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Europäische Radonschutzkonferenz
Radon protection conference
Neue Herausforderungen für die Bau- und Lüftungsbranche
New challenges for the European construction and ventilation branches
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Inhalt / content
Programm / agenda
......................................................................................................................................................................... 04
Willkommen / welcome
................................................................................................................................................................. 06
Teilnehmerliste / participant list
................................................................................................................................................. 08
Referentenliste / list of speakers
................................................................................................................................................
12
Fachvorträge / articles
Jiranek, Martin
Radon protective and remedial measures in the Czech Republic ................................................................................ 14
Scivyer, Chris
The evolution of practical and cost-effective radon solutions for new and existing UK buildings ..............18
Dorusch, Falk; Fregnan, Franco
A Recommendation for Radon Restorations/ Guidance for Optimal Restoration Process ...............................22
Collignan, Bernard
French experience in management and research on the protection of building with respect to radon .....26
Knez, Friderik
Radon mitigation in Slovenia
...................................................................................................................................................... 28
Holmgren, Olli; Arvela, Hannu
Finnish experiences in radon prevention in new construction and energy saving constructions .................32
Karimi-Auer, Julia
Baupraxis betreffend Radon in Österreich – Regelungen, Erfahrungen und Zukunftsausblick ......................36
Bochicchio, Francesco
The approach of the Italian National Action Plan on radon for prevention in new buildings
and mitigation in existing buildings and considerations on the effects of the forthcoming
new European Directive .................................................................................................................................................................40
Kerz, Nicolas
Berücksichtigung von Radon im Bewertungssystem Nachhaltiges Bauen ..............................................................44
Uhlig, Reinhold; Hartmann, Thomas
Regelungen des baulichen Radonschutzes für Neubau und Gebäudesanierung in Deutschland
– aktueller Stand und erforderliche Entwicklungen unter Berücksichtigung der neuen
Europäischen Richtlinie ................................................................................................................................................................. 46
Linares-Alemparte, Pilar
The future Spanish Building Code on the radon protection area and the current regulatory
situation in Spain .............................................................................................................................................................................50
Smyth, Eamonn
Radon in Ireland and the New National Radon Strategy ................................................................................................ 54
Park, Mattias
Radon mitigation in dwellings using radon exctractors .................................................................................................. 58
Notizen / notes
.................................................................................................................................................................................. 60

4 | Programm
agenda | 5
Montag 02.12.2013
Grußworte
9:00 Uhr
Hartmut Schwarze (Sächsisches Staatsministerium für Umwelt und Landwirtschaft)
9:10 Uhr
Alf Furkert (Architektenkammer Sachsen)
9:20 Uhr
Klaus Pöllath (Hauptverband der Deutschen Bauindustrie e.V.)
Fachvorträge
9:30 Uhr
Martin Jiranek (TU Prag, Tschechien): Radonschutz- und -sanierungsmaßnahmen in Tschechien
10:15 Uhr
Chris Scivyer (BRE, UK): Die Entwicklung von praktischen und kosteneffektiven Lösungen für neue
und bestehende Gebäude im Vereinigten Königreich
11:00 Uhr
Falk Dorusch (FHNW, Schweiz): Eine Empfehlung zum Vorgehen bei Radonsanierungen /
Wegleitung für den optimalen Sanierungsablauf
11:45 Uhr
Mittagspause
13:00 Uhr
Bernard Collignan (CSTB, Frankreich): Französische Erfahrungen in Bezug auf Anwendung und
Forschung im Bereich des Radonschutzes in Gebäuden
13:45 Uhr
Friderik Knez (ZAG, Slowenien): Radonsanierung in Slowenien
14:30 Uhr
Olli Holmgren (STUK, Finnland): Finnische Erfahrungen im Radonschutz bei neuen Gebäuden und
beim energetischen Bauen
15:15 Uhr
Kaffeepause
15:45 Uhr
Julia Karimi-Auer (STMK, Österreich): Baupraxis betreffend Radon in Österreich – Regelungen,
Erfahrungen und Zukunftsausblick
16:30 Uhr
Francesco Bochicchio (ISS, Italien): Die Herangehensweise des italienischen Aktionsplans zum
Radonschutz in neuen Gebäuden und bei der Sanierung bestehender Gebäude und Überlegungen
über die Auswirkungen der neuen EU Grundnorm
17:00 Uhr
Nicolas Kerz (BBSR, Deutschland): Berücksichtigung von Radon im Bewertungssystem
Nachhaltiges Bauen
19:00 Uhr
gemeinsames Abendessen im Augustiner an der Frauenkirche
Dienstag 03.12.2013
Fachvorträge
9.00 Uhr
Thomas Hartmann (ITW Dresden): Regelungen des baulichen Radonschutzes für Neubau und Ge-
bäudesanierung in Deutschland – aktueller Stand und erforderliche Entwicklungen unter Berück-
sichtigung der neuen Europäischen Richtlinie
9:45 Uhr
Pilar Linares (CSIC, Spanien): Die zukunftsfähige spanische Baurichtlinie zum Radonschutz und die
gegenwärtige Rechtssituation in Spanien
10.30 Uhr
Kaffeepause
11:00 Uhr
Eamonn Smyth (DECLG, Irland): Radon in Irland und die neue nationale Radonstrategie
11:45 Uhr
Mattias Park (Corroventa, Schweden): Radonminimierung in Gebäuden mit Lüftungsanlagen
12:30 Uhr
Mittagspause
13:30 Uhr
Malgorzata Wysocka / Krysztof Ciupek (Polen): Radonmessungen in Polen
Podiumsdiskussion
14:15 Uhr
Offene Fragen vor Umsetzung der EU-Grundnorm
Diskussionsleitung: Oliver Solcher (Fachverband Luftdichtheit im Bauwesen e. V.)
15:45 Uhr
Ende der Veranstaltung
Monday, 2nd December 2013
Opening session
9.00 h
Hartmut Schwarze (Ministry for the Environment and Agriculture)
9.10 h
Alf Furkert (Chamber of Saxon Architects)
9.20 h
Klaus Pöllath (German Construction Industry Federation)
Presentations
9.30 h
Martin Jiranek (Czech Technical University Prague): Radon protective and remedial measures
in the Czech Republic
10.15 h
Chris Scivyer (BRE, UK): The evolution of practical and costeffective radon solutions for new and
existing buildings in the UK
11.00 h
Falk Dorusch (FHNW, Switzerland): A Recommendation for Radon Restorations /
Guidance for Optimal Restoration Process
11.45 h
Lunch break
13.00 h
Bernard Collignan (CSTB, France): French experience in management and research on the protection
of buildings with respect to the radon
13.45 h
Friderik Knez (ZAG, Slovenia): Radon mitigation in Slovenia
14.30 h
Olli Holmgren (STUK, Finland): Finnish experiences in radon prevention in new construction and
energy saving constructions
15.15 h
Coffee break
15.45 h
Julia Karimi-Auer (STMK, Austria): Building practices concerning radon in Austria – regulations,
experiences and future prospects
16.30 h
Francesco Bochicchio (ISS, Italy): The approach of the Italian National Action Plan on radon for pre-
vention in new buildings and mitigation in existing buildings and consideration on the effects of the
forthcoming new European Directive
17.00 h
Nicolas Kerz, (BBSR, Germany): Addressing of Radon at the Assessment System Sustainable Building
19.00 h
Dinner in the Restaurant Augustiner next to Womans Church
Tuesday 3rd December 2013
Presentations
9.00 h
Thomas Hartmann (ITW Dresden): Regulations of edificial radon protection for new and existing
buildings in Germany – current state and required developments considering the upcoming BSS
9.45 h
Pilar Linares (CSIC, Spain): The future Spanish Building Code on the radon protection area and the
current regulatory situation in Spain
10.30 h
Coffee break
11.00 h
Eamonn Smyth (DECLG, Ireland): Radon in Ireland and the new national radon strategie
11.45 h
Mattias Park (Corroventa, Sweden): Radon mitigation in dwellings using radon exctractors
12.30 h
Lunch break
13.30 h
Malgorzata Wysocka / Krysztof Ciupek (Poland): Radon measurements conducted in Poland
Panel discussion
14.15 h
Open questions regarding the implimantation of the Europian directive
Chair: Oliver Solcher (Association for Air-Tightness in Buildings)
15.45 h
End of workshop
Programm
agenda

Willkommen
welcome
Zur europäischen Radonschutzkonferenz am 02. und 03. De-
zember 2013 heißen wir Sie herzlich in Dresden willkommen.
Das Schwerpunktthema dieser Veranstaltung ist der bauli-
che Radonschutz vor dem Hintergrund der anstehenden EU-
Richtlinie - RICHTLINIE DES RATES zur Festlegung grundle-
gender Sicherheitsnormen für den Schutz vor den Gefahren
einer Exposition gegenüber ionisierender Strahlung und zur
Aufhebung der Richtlinien 89/618/Euratom, 90/641/Eura-
tom, 96/29/Euratom, 97/43/Euratom und 2003/122/Euratom.
Diese Richtlinie steht kurz vor der Verabschiedung. Die Mit-
gliedstaaten der EU sind verpflichtet, sie bis zum Jahr 2018
in nationales Recht umzusetzen. Sie enthält erstmals ver-
bindliche Regelungen zur Einhaltung eines Referenzwertes
für Radon in Gebäuden. Es handelt sich um den für Arbeits-
plätze und Wohngebäude einheitlichen Wert von 300 Bq/m
3
.
Der Freistaat Sachsen will die Zeit bis zur Umsetzung in
deutsches Recht nutzen, um sich und alle Betroffenen mög-
lichst gut auf diese Umsetzung vorzubereiten. Dazu wur-
de eine Radon-Strategie beschlossen, in der die Aktivitäten
zum Erreichen dieser Zielsetzung festgeschrieben wurden.
Diese bauen auf den zahlreichen bisherigen Aktivitäten des
Freistaates Sachsen zum Radonschutz
(www.radon.sachsen.
de) auf und berücksichtigen die Forderungen zum Radon-
schutz an Arbeitsplätzen (Artikel 54) und zum Radonschutz
in Wohnungen (Artikel 74) der o. g. Richtlinie.
Neben der Information der Öffentlichkeit und der Durch-
führung von Messprogrammen stellen Weiterbildungsmaß-
nahmen im Baubereich die wesentlichen Bestandteile dieser
Strategie dar.
We welcome you to the European Radon Conference in
Dresden, December 2nd and 3rd 2013!
The focus of this convention is constructional and physical
radon protection against the background of the upcoming
European Union (EU) basic safety standards – Council Di-
rective laying down basic safety standards for protection
against the dangers arising from exposure to ionising ra-
diation; replacing 89/618/Euratom, 90/641/Euratom, 96/29/
Euratom, 97/43/Euratom and 2003/122/Euratom.
This directive is on the brink of enacting. EU Member States
are obliged to implement it in national law until 2018. For
the first time binding regulations to comply with a reference
level for indoor Radon are part of this directive. At work-
places and in dwellings the standardized value of 300 Bq/
m
3
is stipulated.
The German Federal State of Saxony is intending to use the
time until the implementation into German law to prepare
the regulatory body and all concerned parties as good as
possible for 2018. Therefor a Radon-Strategy was developed
and concluded where the activities to accomplish this aim
were defined.
These activities are based on numerous previous programs
and actions for radon protection of the State of Saxony.
They take the requirements of the new Council Directive
into consideration, especially regarding radon protection on
workplaces (article 53(54)) and radon protection in dwel-
lings (article 74).
Beside the information of the public and the realization of
measurement programs, training measures in the building
construction sector are the main components of this strategy.
In der Praxis kann Radonschutz entweder durch eine aus-
reichende Dichtheit der erdberührenden Bauteile eines Ge-
bäudes, durch das Absaugen und Ausleiten der Bodenluft
unterhalb eines Gebäudes oder durch eine ausreichende Be-
lüftung im Gebäude erreicht werden. Diese im Grunde einfa-
chen Sachverhalte gilt es an die Hauseigentümer, aber auch
an die Träger öffentlicher Gebäude sowie an alle betroffenen
Institutionen des Baubereiches zu vermitteln. Des Weiteren
müssen die Betroffenen über die technischen Maßnahmen
zum Erreichen der Gebäudedichtheit und / oder der geeig-
neten Methode zur Bodenluftableitung oder zum Erreichen
der Luftwechselrate informiert werden.
In den meisten europäischen Ländern gibt es schon seit
vielen Jahren Aktivitäten zum Radonschutz. Einige Länder
haben gesetzliche Regelungen entwickelt, welche über die
der anstehenden Richtlinie hinausgehen.
Der Freistaat Sachsen will die Kenntnisse und die Erfahrun-
gen, die bei den europäischen Nachbarn vorhanden sind,
nutzen. Er pflegt aus diesem Grund mit einigen europäi-
schen Kollegen bereits seit vielen Jahren einen fachlichen
Austausch.
Wir freuen uns, dass für die Konferenz 14 Referenten aus 13
europäischen Ländern gewonnen werden konnten, die ihre
Erfahrungen und Erwartungen in Bezug auf die anstehen-
den Regelungen vorstellen.
Auch freuen wir uns, dass viele Teilnehmer aus den unter-
schiedlichsten Berufsfeldern und Institutionen sich für die-
ses Thema interessieren und bedanken uns für ihre Teilnah-
me und ihren individuellen Beitrag zu dieser Konferenz.
In practice radon protection can be realized either by suf-
ficient airtightness of the building parts with direct con-
tact to the foundation, or by extraction and discharge of
the soil air below a building, or by adequate ventilation of
the building. These essentially simple facts must be com-
municated to house owners but also to responsible persons
for public buildings and to all concerned institutions in the
building construction area. Additionally they have to be in-
formed about the technical means to attain airtightness of
buildings and/or adequate methods to extract soil air or to
achieve the required rate of air change.
In most of the European countries since many years acti-
vities for radon protection exist. Some countries developed
legal regulations with standards exceeding (i.e. below) those
of the new Council Directive.
The Federal State of Saxony is happy to have advantage
of know-how and experiences of the European neighbors
and is willing to share own knowledge and experience with
them. Therefor since many years fruitful exchange with
some of the European colleagues was practiced.
We are happy to welcome 14 speakers from 13 European
countries to our conference who will present their experi-
ences and expectations regarding the upcoming regulation.
And we are very happy too about the great number of par-
ticipants from different professional fields and institutions
who are interested in this topic.
We want to thank you all for your participation and your
individual contributions to this conference.
6 | Willkommen
welcome | 7

8 | Teilnehmerliste / participant list
Teilnehmerliste / participant list | 9
Üllar Alev
Tallinn University of Technology
Estonia
Roland Baumann
Institut f. Strahlenschutz
Germany
Gianluca Bertoni
Econs SA
Switzerland
Tobias Beyermann
Gebäudemesstechnik
Germany
Steffen Bieder
BFW Mitteldeutschland e.V.
Germany
Patrycja Bielawska-Roepke
Ingenieurkammer Sachsen
Germany
Gerhard Binker
Binker Materialschutz GmbH
Germany
Luca Bonzi
Tecnavia S.A.
Switzerland
Patrick Bruggmann
Ampack AG
Germany
Krzysztof Ciupek
Central Laboratory for Radiological Protection
Poland
Roberto Colucci
Tecnavia S.A.
Switzerland
Teilnehmerliste / participant list
Elzbieta Domin
Wroclaw University of Technology
Poland
Katrin Dörfelt
Verein RADIZ Schlema e. V.
Germany
Anita Duschek
Landkreis Zwickau
Germany
Antje Eichler
Hauptverband der Deutschen Bauindustrie e. V.
Germany
Freia Frankenstein-Krug
Sächsische Energieagentur SAENA GmbH
Germany
Bettina Gabriel
Staatsbetrieb Sächsisches Immobilien- und
Baumanagement (SIB)
Germany
Kunibert Gerij
BFW Berlin
Germany
Julia Gilberg
Technische Universität Dresden
Germany
Volker Grimm
Technische Hochschule Mittelhessen
Germany
Gerlinde Frieda Grimm
Technische Hochschule Mittelhessen
Germany
Uwe Heidrich
Hochschule Zittau/Görlitz
Germany
Ivo Heiland
Staatsbetrieb Sächsisches Immobilien-
und Baumanagement
Germany
Thomas Heinrich
Staatliche Betriebsgesellschaft für Umwelt und
Landwirtschaft (BfUL)
Germany
Hartmut Herzberg
Herzberggebäudeanalyse GmbH
Germany
Michael Hesse
SealEco GmbH
Germany
Sue Hodgson
Public Health England - Centre for Radiation Chemical
and Environmental Hazards
England
Grit Höfer
Bauindustrieverband Sachsen/Sachsen-Anhalt
Germany
Gunnar Horak
SARAD Geolab GmbH
Germany
Christian Huber
Atelier für Architektur
Germany
Stephanie Hurst
Sächsisches Staatsministerium für Umwelt und
Landwirtschaft (SMUL)
Germany
Oliver Jann
Bundesanstalt für Materialforschung und –prüfung
Germany
Thomas Junge
DREWAG-Stadtwerke Dresden
Germany
Andrea Kaltz
Sächsisches Landesamt für Umwelt, Landwirtschaft
und Geologie (LfULG)
Germany
Joachim Kemski
Sachverständigenbüro
Germany
Klaus Konschak
GAMMA-CONSULT STREHLA
Germany
Heinz-Günter Kraus
Verein RADIZ Schlema e. V.
Germany
Jörg Kropp
Hochschule Bremen
Germany
Agata Kula
Wroclaw University of Technology
Poland
Frank Leder
Sächsisches Staatsministerium für Umwelt und
Landwirtschaft (SMUL)
Germany
Bernd Leißring
GEOPRAX - Bergtechnisches Ingenieurbüro
Germany
Dana Marceta
Landesamt für Umwelt, Wasserwirtschaft und
Gewerbeaufsicht Rheinland-Pfalz
Germany

Teilnehmerliste / participant list | 11
Hans-Christoph Mehner
Hochschule Zittau-Görlitz
Germany
Winfried Meyer
Bundesamt für Strahlenschutz
Germany
Wolfgang Misch
Deutsches Institut für Bautechnik (DIBt)
Germany
Jens Müller
Gemeindeverwaltung Bad Schlema
Germany
Dimitar Natchev
Ingenieurkammer Bulgarien
Bulgaria
Oscar Nordlund-Ristori
Independia Group
Sweden
Jerzy Olszewski
Institute of Occupational Medicine
Poland
Sandra Patalla
RheinEnergie AG
Germany
Ralf Pörschke
Architekt
Germany
Werner Preuße
Staatliche Betriebsgesellschaft für Umwelt und
Landwirtschaft (BfUL)
Germany
Roland Preusser
AQUATERRA Dresden GmbH
Germany
Tadeusz Przylibski
Wroclaw University of Technology
Poland
Axel Puhlmann
BFW Bau Sachsen e.V.
Germany
Kathrin Reichelt-Georgi
Sächsisches Staatsministerium des Innern
Germany
Wolfgang Ringer
Österreichische Agentur für Gesundheit und
Ernährungssicherheit (AGES)
Austria
Josef Rittgen
Rittgen - Beratende Ingenieure
Germany
Franz Anton Rößler
Technische Hochschule Mittelhessen
Germany
Andrea Sperrhacke
Sächsisches Landesamt für Umwelt, Landwirtschaft
und Geologie (LfULG)
Germany
Maria Stefano
Ingenieurkammer Bulgarien
Bulgaria
Karsten Steudel
Landratsamt Zwickau
Germany
Kurt Sudeck
Germany
Corina Thiele
Sächsisches Staatsministerium der Finanzen
Germany
Markus Trautmannsheimer
Bayerisches Staatsministerium für Umwelt und Verbraucherschutz
Germany
Cornelia Trültzsch
Sächsisches Staatsministerium für Wirtschaft, Arbeit und Verkehr
Germany
Verena Tykiel
Deutsches Institut für Bautechnik (DIBt)
Germany
Frank Ullrich
Thüringer Landesanstalt für Umwelt und Geologie (TLUG)
Germany
Corina Unger
SARAD GmbH
Germany
Giancarlo Vanoni
Tecnavia S.A.
Italy
Katarzyna Walczak
Institute of Occupational Medicine
Poland
Sabine Wehrenpfennig
Landeshauptstadt Dresden, Stadtplanungsamt
Germany
Johan Wintheim
Independia Group
Germany
Friedrich Wodarczack
Hochschule Zittau-Görlitz - University of Applied Sciences
Germany
Jana Ziemer
GICON GmbH
Germany
10 | Teilnehmerliste / participant list

12 |
12 |
articles
Francesco Bochicchio
Istituto Superiore di Sanità
(Italian National Institute of Health)
Italy
Bernard Collignan
Centre Scientifique et Technique du Bâtiment
(Scientific and Technical Center for Building)
France
Falk Dorusch
FHNW, University of Applied Sciences Northwestern
Switzerland
Switzerland
Alf Furkert
Architektenkammer Sachsen
(Chamber of Saxon Architects)
Germany
Thomas Hartmann
Institut für Technische Gebäudeausrüstung Dresden (ITG)
(Institute for Building Systems Engineering Dresden)
Germany
Olli Holmgren
Radiation and Nuclear Safety Authority - STUK
Finland
Martin Jiranek
Czech Technical University Prague
Czech Republic
Julia Karimi-Auer
Amt der Steiermärkischen Landesregierung
(Agency of the Styrian Government)
Austria
Nicolas Kerz
Bundesinstitut für Bau-, Stadt- und Raumforschung (BBSR)
(Federal Institute for Research on Building, Urban Affairs and
Spatial Development)
Germany
Referentenliste / list of speakers
Friderik Knez
ZAG - Slovenian National Building and Civil
Engineering Institute
Slovenia
Pilar Linares-Alemparte
Eduardo Torroja Institute of Construction Sciences
(CSIC)
Spain
Mattias Park
Corroventa Avfuktning AB
(Corroventa dehumidification)
Sweden
Klaus Pöllath
Hauptverband der Deutschen Bauindustrie e. V.
(German Construction Industry Federation)
Germany
Hartmut Schwarze
Sächsisches Staatsministerium für Umwelt und
Landwirtschaft (SMUL)
(Saxon State Ministry of the Environment
and Agriculture)
Germany
Christopher Scivyer
Building Technology Group, (BRE)
England
Eamonn Smyth
Dep. of the Environment, Community and Local
Government (DLCLG)
Ireland
Oliver Solcher
Fachverband Luftdichtigkeit im Bauwesen e. V.
(Association for Air-Tightness in Building)
Germany
12 | Referentenliste / list of speakers
Fachvorträge / articles | 13

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Abstract
Principles of designing and realization of radon preventive
and remedial measures in the Czech Republic are descri-
bed. Requirements for radon-proof membranes and other
components that are part of radon reduction systems are
presented.
1. Protection of new buildings
Principles of protection
Design and realization of radon preventive measures has
been standardised in the Czech Republic since 1995, when
the Czech national standard CSN 730601 „Protection of
buildings against radon from the soil“ [1] was introduced.
The way in which protection is carried out depends on the
radon index of the building. This quantity is determined
by the radon index of the foundation soils, type of buil-
ding and its position in the soil profile with respect to the
ground level and by all building activities influencing the
permeability of foundation soils. Principles of protecting
buildings with respect to radon index of the building are
summarized in Tab. 1.
Radon protective and remedial measures
in the Czech Republic
Martin Jiránek
Czech Technical University in Prague, Faculty of Civil Engineering,
Czech Republic, email: jiranek@fsv.cvut.cz
14 | Fachvorträge / articles
Fig. 1. Network of perforated pipes convenient for new buildings
Radon-proof membrane
The only materials that may be used as radon-proof mem-
branes are those with barrier properties that have been
verified by measuring the radon diffusion coefficient [2,
4, 5], and that have proven durability corresponding to
the expected lifetime of the building. Bitumen membranes
with Al foil cannot serve as a radon-proof membrane due
to their very low tear resistance, and plastic membranes
with dimples are unsuitable due to evidence that it is al-
most impossible to form airtight joints with this materi-
al. Applicability of the particular membrane for a specific
dwelling is derived from the calculation of its thickness.
The calculation takes into account the radon diffusion co-
efficient in the insulation, soil parameters (radon concen-
tration and permeability) and house characteristics (area
in contact with the soil, air exchange rate and interior air
volume) [1, 3].
Sub-slab ventilation
Sub-slab ventilation systems in new buildings are usually
provided by a network of flexible perforated pipes placed
in a sub-floor layer of coarse gravel. Perforated pipes are
connected to a vertical exhaust pipe, which terminates
above the roof. A typical arrangement of a sub-slab venti-
lation system is shown in Fig. 1, and a floor structure with
soil ventilation is presented in Fig. 2. The soil air is sucked
from the perforated pipes by a fan or rotating cowl that is
installed at the top of the vertical exhaust pipe.
Tab. 1. Principles of protecting new buildings
Radon index
of the building
Protection
Low
Continuous waterproof membrane
Medium
Continuous radon-proof membrane
High
Continuous radon-proof membrane in
combination with either sub-slab
ventilation, or air-gap ventilation
If the permeable gravel layer is placed under the house or the
ground floor is equipped with an underfloor heating, radon-
proof membrane must be provided in combination with either
sub-slab ventilation, or air-gap ventilation regardless of the
radon index of the building.
Fig. 2. Floor structure with the soil ventilation
Fig. 3.
Floor structure
with an air gap
above or below
a radon-proof
membrane
Floor air gap ventilation
Air gaps in floor structures are usually formed by plastic
membranes with dimples or various types of plastic pro-
filed components. The floor air gap can be created above or
under a radon-proof membrane (Fig. 3). The best solution
is to ventilate the air gap above the roof. Natural or forced
ventilation can be used. A slight underpressure within the
gap is recommended
Fachvorträge / articles | 15

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16 | Fachvorträge / articles
2. Remediation of existing buildings
Principles of remediation
The type and the level of remediation depends on the de-
gree of exceeding the reference level 400 Bq/m
3
for indoor
radon concentration, type of the house and applicability of
the measure into the existing structure.
Buildings in which the reference level is not so much ex-
ceeded (indoor radon concentration is below 600 Bq/m
3
)
can be easily and inexpensively mitigated by sealing of
radon entry routes, improving the cellar – outdoor ventila-
tion, preventing the air movement from the cellar into the
first floor, increasing the ventilation intensity, etc.
Fig. 4. Perforated
tubes drilled into
the sub-floor layer
from the cellar
Fig. 5. Perforated
tubes drilled into
the sub-floor layer
from the external
trench
Buildings with indoor radon concentration above 600 Bq/
m
3
should be remediated by more effective methods. The
basic and the most effective solution is the installation
of a sub-slab depressurization. The preference should be
given to systems that can be installed without the recons-
truction of floors and obstructions within the living space.
The soil air can be sucked from perforated tubes drilled
into the sub-floor layer from the cellar (Fig. 4) or from an
external trench excavated in the ground along one or more
sides of the house (Fig. 5). Other possibility is to install the
perforated tubes from the floor pit excavated in one room,
where afterwards a new floor with a radon-proof memb-
rane had to be placed (Fig. 6). Beneath each habitable room
at least one perforated pipe should be inserted.
In houses with damp walls and floors the possible best so-
lution could be the installation of ventilated floor air gaps
or replacement of existing floors by new ones in which the
radon-proof insulation and the soil depressurization sys-
tem will be combined. Flexible perforated pipes placed in a
sub-floor layer of coarse gravel (Fig. 7) are usually used for
soil air suction. Pipes are laid along walls in order to stop
radon from entering the dwelling through the wall-floor
joint or through vertical holes and cracks within the wall.
Passive ventilation of soil or air gaps is usually not suf-
ficient and therefore forced ventilation is recommended.
The fan is usually installed at the top of a vertical exhaust
Fig. 7. Network of perforated pipes in the drainage layer suitable
for remediation
Fig. 6. Perforated tubes installed from the floor pit excavated in
one room
3. Acknowledgement
This paper has been supported by the research project P104/11/1101, funded by the Grant Agency of the Czech Republic.
References
1. SN 73 0601 Protection of houses against radon from the soil. Czech Standards Institute, Praha 2006
2. Jiránek M, Fronka A.: New technique for the determination of radon diffusion coefficient in radon-proof membranes. Radiation
Protection Dosimetry 2008; 130(1): 22-25.
3. Jiránek M, Hulka J.: Applicability of Various Insulating Materials for Radon Barriers. In: The Science of the Total Environment 272
(2001), pp 79-84
4. Jiránek M, Svoboda Z.: Transient radon diffusion through radon-proof membranes: A new technique for more precise determinati-
on of the radon diffusion coefficient, Building and Environment (2008), doi:10.1016/j.buildenv.2008.09.017
5. Jiránek M., Kotrbatá M.: Radon diffusion coefficients in 360 waterproof materials of different chemical composition. In: Radiation
Protection Dosimetry (2011), doi:10.1093/rpd/ncr043
pipe or in a suitable place in the garden. Passive systems
must be installed in such a way that they can be very easily
changed to forced systems.
In existing houses radon-proof insulation, as a single mea-
sure is not so effective, because it usually cannot be ap-
plied under the walls and thus radon can be still transpor-
ted through wall-floor joints. Therefore combination with
a soil ventilation system is recommended.
Fachvorträge / articles | 17

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image
image
image
image
Sump systems (sub-slab depressurisation) Each can
be supplemented by additional sealing works to
floors, walls and service penetrations.
Average indoor radon levels exceeding 20,000 Bq/m
3
have
been lowered to below the UK recommended action level
of 200 Bq/m
3
using these techniques. Typically for homes
built since the 1950’s these measures are unlikely to cost
more than £1200 to install and in many cases can be ins-
talled on a do-it-yourself basis by the homeowner for half
the cost.
The UK government have funded a series of radon aware-
ness campaigns since the late 1980’s which have targeted
areas known to have elevated radon levels. Managed on
a national basis these campaigns tried to identify dwel-
lings with elevated radon levels and encourage owners to
remediate. As part of this process occupiers were offered
free measurement, supplemented by guidance on remedi-
al measures, via leaflets, telephone help lines and more
recently Websites. Whilst some limited grants are also
available most remedial measures have to be funded by
the homeowner.
Over the last 10 years or so the government has re-fo-
cussed its campaigns to fund local awareness campaigns
for which the local authorities provide the public face. The
key features of these campaigns are:
Offering free measurement via the local authority
Running training events for local authority staff,
housing professionals, surveyors, builders and medi-
cal practitioners.
Introduction
The UK radon programme has been running for nearly 30
years, in which time a considerable amount of progress has
been made in understanding the physics of radon, develo-
ping a comprehensive range of cost effective radon solu-
tions for both new and existing buildings, and engaging
with officials and professionals in health, construction,
and property transactions, as well as the general public.
Problems with radon in water and radon emanating from
building materials are both rare in the UK. We are primarily
concerned with reducing the amount of radon that enters
buildings from the ground.
Reducing radon levels in existing buildings
Many different remedial methods have been trialled in the
UK over the years with varying degrees of success. As a re-
sult of this work we now have a set of three key techniques
that can be used to solve the majority of radon problems in
existing homes and other buildings:
Improved house ventilation
Improved underfloor ventilation (natural or mechani-
cal ventilation)
‚The evolution of practical and
cost-effective radon solutions for new
and existing UK buildings‘
Chris Scivyer MCIOB
Principal Consultant, Building Research Establishment Limited,
Garston, Watford WD25 9XX, UK
18 | Fachvorträge / articles
Figure 2 externally located sump system (left), whole house
ventilation system (right)
Figure 1: the various routes by which radon gas enters a building
from the ground.
Figure 3 full radon protection to a suspended concrete floor (left) and an in-situ concrete floor (right).
Local public exhibitions and surgeries with national
experts and local contractors available to advise on
solutions
Providing advice locally and in some cases home
visits
These activities have proven very successful in increasing
the uptake of measurement and have had resulted in in-
creased uptake of remediation works. Their success is due
to the local authorities being seen to lead the campaigns.
Being managed locally the public have a local point of con-
tact for advice and guidance. House owners trust the local
authority more than the government so are more willing to
act! The key aims have been to offer simple and consistent
messages on health risks and remediation methods, and to
minimise effort demanded of householders.
With the drive for improving energy efficiency in UK ho-
mes additional guidance is being developed to ensure that
radon is considered at the same time. It is recommended
that homes are tested for radon before works are underta-
ken and where appropriate radon solutions can be incor-
porated into refurbishment works.
Protecting new buildings in the UK
The various building regulations covering England and
Wales, Scotland and Northern Ireland require radon pro-
tection to be provided in all new buildings in areas of si-
gnificant radon risk based upon maps derived from house
measurement and geological data.
For England and Wales, depending upon the risk in the
area, there are three levels of protection:
Areas where no protective measures are required
Basic radon protection (a radon barrier across the
footprint of the building).
Full radon protection (radon barrier supplemented by
a sump or subfloor void to enable subfloor depressu-
risation to be applied later should it prove necessary
see Figure 3.
Research carried out in the early 1990’s suggested a rela-
tively high success rate with these techniques. In the case
of protected suspended concrete floors with ventilated
underfloor spaces 99% achieved and an average indoor
Fachvorträge / articles | 19

20 | Fachvorträge / articles
radon level of less than 200 Bq/m
3
. In fact the average for
all floor types was close to 55 Bq/m
3
. Interestingly proper-
ties re-tested 20 years later showed little change in the ef-
fectiveness of the protection measures. There was a slight
increase nearer to 60 Bq/m
3
.
Whilst these results are very good recent changes to buil-
ding regulations, to improve energy efficiency of buildings
and to provide level access for disabled people, conflict
with the detailing applied for radon protection. Further-
more we have noticed a slight increase in the number of
recently built properties being identified with elevated ra-
don levels. Further investigation is needed, but it appears
that changes in design to satisfy level access are compli-
cating the design and installation of the radon barrier and
provision of underfloor ventilation. BRE are about to esta-
blish a working group of interested parties from the cons-
truction industry to review existing construction detailing
and to develop revised guidance to support the Building
Regulations. In addition it is intended to increase the ge-
neral awareness of providing radon protection during con-
struction. The message has unfortunately been somewhat
drowned out by the drive for energy efficiency.
Training Builders
It has always been difficult to provide adequate radon
training for building professionals and operatives due to
the transitory nature of the construction industry and the
way in which radon levels vary from area to area across
the UK. One-off training events have proven successful,
particularly when organised to coincide with a local radon
measurement campaign and the events are subsidised. The
incentive for builders to attend is the likelihood that local
properties will require remediation. But interest tends to
fade as the show leaves town! For areas where it is not
viable to organise training events BRE have recently deve-
loped the first of a potential series of Web based training
packages. There is a small charge, but anybody wherever
they are located can access it.
Radon in the Workplace
The UK has long had regulations to address the risk from
radon in the workplace. Unfortunately the regulations
have never really been enforced. The better employers have
taken action but most have not. This is an area in which
further awareness raising activities are currently being
discussed.
Radon and buying and selling of property
Encouraging radon measurement and remediation as part
of the buying and selling process is an important way of
reducing radon risk. People are more likely to install radon
reduction measures as part of other works that are being
funded when moving into a property. Radon has for some
time been one of the issues that is included within the
standard searches that are carried out by Solicitors and
Estate agents for the purchaser prior to purchase.
Conclusion
Over the last 20 years the UK has carried out a conside-
rable amount of work to develop a range of cost-effective
technical solutions for reducing radon risk in both existing
and new buildings. We already satisfy the requirements
of the new European Basic Safety Standard but there is
further work to be done. The principal aims now are to
increase the uptake of remediation measures in existing
buildings and to improve the standard and consistency of
protective measures installed in new buildings.
For further information visit the BRE website at
www.bre.co.uk

image
Summary
The Swiss Federal Office of Public Health (FOPH) assigned
the Institute of Energy in Building to provide a specialist
department for radon in the German speaking part of Swit-
zerland. Objectives are to support the communication and
cooperation between radon experts all over Switzerland.
The topic is included in trainings and education programs.
Concerned house owners are supported with technical ex-
pertise in case of new building programs and restoration
measures to reduce the radon concentration in buildings.
Zusammenfassung
Das Schweizerische Bundesamt für Gesundheit (BAG) hat
das Institut Energie am Bau der Fachhochschule Nord-
westschweiz mit der Führung einer Radonfachstelle für
die Deutschschweiz beauftragt. Ziel des Mandats ist es,
den fachlichen Austausch der Radonfachstellen der West-
schweiz und des Tessin sowie die Kooperation unabhängi-
ger Radonexperten zu fördern. Ebenfalls wird das Thema
„Radon“ in die Aus- und Weiterbildung eingebracht. Die
enge Vernetzung mit dem BAG stärkt den Austausch von
Kompetenzen in der Radonprävention und -sanierung.
Eine weitere Aufgabe der Radonfachstelle besteht darin,
betroffene Hauseigentümer mit technischer Expertise bei
Neubauprojekten und Sanierungsmassnahmen zur der Re-
duktion des Radongehalts in Gebäuden zu unterstützen.
Für den täglichen Gebrauch ist es hilfreich, das Procedere
einer Radonsanierung zu strukturieren und zu vereinheit-
lichen. Um Radonfachpersonen, involvierten Planern und
andere interessierte Fachleute die Routine einer Radon-
sanierung zu erleichtern, wird ein strukturiertes Vorgehen
als Wegleitung, Kommunikationshilfe und Gedankenstütze
vorgeschlagen.
Established Instruments/tools:
The Swiss Federal Council adopted a national action plan to
protect the population from radon in habitable rooms. This
plan defines appropriate and effective measures, based on
newest scientific research and international standards. The
topic of radon has been incorporated into updated regula-
tions and rules [1] and is applied in ‚cutting edge‘ building
standards [2,3].
There are a lot of resources available for radon experts
for planning and execution of preventive measures and
remedial work [4], such as extensive building-reports on
remedial work, documented examples of restorations [5],
recommendations for efficient use of building technology
as well as the radon-manual of Switzerland [7]. Radon ex-
perts are strongly advised to document all remedial work
and use a standardized questionnaire.
Recommended Action
For daily use, it is advisable to structure and unify the ap-
proach of remedial work for radon. Radon experts, engi-
neers and other interested parties are given an approach that
can be used as guide, communication aid and mnemonic aid.
A Recommendation for Radon Restorations/
Guidance for Optimal Restoration Process
Eine Empfehlung zum Vorgehen bei Radonsanierungen/
Wegleitung für den optimalen Sanierungsablauf
Falk Dorusch, Franco Fregnan, (FHNW, Switzerland)
Institute of Energy in Building, School of Architecture, Civil Engineering and Geomatics,
University of Applied Sciences and Arts Northwestern Switzerland
www.fhnw.ch/iebau,
franco.fregnan@fhnw.ch, falk.dorusch@fhnw.ch
22 | Fachvorträge / articles
Fachvorträge / articles | 23

24 | Fachvorträge / articles
Phase 0: First Contact
Usually a radon expert is contacted by concerned building
owners, engineers or architects.
In the first conversations it‘s important to evaluate the
current situation and to find out about any suspicion the
concerned person might have. The first contact should also
be used to get an overview about planned, ongoing and
finished work on the building in question. It can be helpful
to obtain blueprints, cross-sections and pictures of the
building and, if available, any existing data on the radon
contamination.
The client should be asked for any available data while
both parties should agree on confidentiality. Based on the
available data, the radon expert can get a first overview of
the situation. This first consultation is usually free of charge.
Phase 1: Technical Pre-Project, Cost Quotation
If the client shows interest for further support by the ex-
pert, a technical pre-project should be worked out.
As a preparation, all available documentation is reviewed
for its correctness and completed where necessary. Buil-
ding applications can be used as further resources. All
building plans should be investigated for potential com-
promised rooms, entry points for radon as well as possible
ways for it to spread in a building.
The general state of the building as well as the properties
of the building should be looked upon closely. The struc-
ture of the building, the wall-, ceiling- and floor-compo-
sition and vertical or horizontal punctures in the building
should be identified and evaluated.
Special care should be given to all components that are
in contact with the surrounding earth. These components
should be analyzed with great care, particularly with re-
gards to potential leaking. If data exists on the radon con-
tamination, it is to be checked for plausibility and reprodu-
cibility. It should be clear from the data when, where and in
what time-interval the data have been acquired. The exact
place of the measurement should be documented and ac-
cessible in the building.
The geologic situation at the building location should be
evaluated. Ideally a high-resolution geological map of
the area can be used and examined for clefts, cleaves and
groundwater leakages in close proximity to the building. It
can be useful to consult an available ground expert testi-
mony or to evaluate drilling expertises e.g. from geother-
mal probes.
For exact assessment a visit of the site and the building is
insightful. The visit can be combined with a meeting with
the owner or engineer. Visiting the building, it is important
to compare the blueprints with the real circumstances and
document the building by taking pictures. The structure
and composition of the floors, walls and suspended cei-
lings should be investigated closely and potential entry
points for radon identified and documented.
Buildings with multiple floors offer the challenge of iden-
tifying paths for radon by air convection.
Sources of radon in the building itself, such as floor co-
vering, stone workspaces and collections of minerals
should be identified. The result of the technical pre-project
should be a proposal with suggestions on further assess-
ments (measurements, analysis of building parts), a list of
potential restoration measures and a time schedule. The
technical pre-project is usually conducted with a fixed
time-budget and the cost is included in the total project.
Phase 2: Analysis, Inventory of Deficiencies
Primarily potentially highly radon affected rooms in the
building should be identified. Short measurements of po-
tential entry points for radon - radon sniffing - during the
first visit as well as checking the leakage of isolated rooms
in the building with blower-door-measurements during
the first visit would be ideal. If the available documents
offer no insight into the composition of walls, ceilings and
floors, the first visit also offers an opportunity for sensory
investigation or a sounding drill hole.
The results of the visit have to be well documented. The
FOPH offers a template for a site inspection protocol. The
protocol should give the house owner enough informati-
on to get a clear picture of the radon risk his building is
subjected to.
Possible remedial work should be outlined in the proto-
col which should also include recommendations from the
expert.
Results of the investigation should be properly explained
to the client as well as possible consequences.
The first visit can be followed up by further meetings if
the owner asks for it or long-term measurements in the
building, e.g. for a heating period, are required. The expert
contacts the cantonal radon expert or the FOPH if necessary.
Phase 3: Selection of Remedial Work
The Selection of an appropriate remedial method is part of
a multifarious decision process.
With the available data, the expert works out remedial
work for the particular building.
A test might be necessary to see whether a given material
or installation would provide a good solution for a parti-
cular building.
The expert researches appropriate material, contacts tech-
nical firms, manufacturers and suppliers, checks quotes
and creates a definite offer of the remedial work.
Phase 4: Counsel and Supervision During the Remedial
Work
During the remedial work the expert can take on many
different roles. In smaller projects he can, mandated by
the owner, act as general contractor and coordinate the
involved parties and artisans. He suggests the contractors
and organizes the different work orders. He takes care of
the materials necessary and supervises the whole process.
If needed, an external expert can be involved, e.g. from ma-
nufacturers, consultants from build material producers etc.
If building technology such as as ventilation system is in-
stalled, the radon expert controls the startup, supervises
the approval of the construction and optimizes it. After
everything has been installed, another long-term measu-
rement of radon contamination should be done.
All work and results should be documented in a report. This
report should then be made available to the house owner.
Phase 5: Supervision After Remedial Work
After all remedial work has been concluded, the owner of
the building should be informed of the success of the re-
medial work.
It is possible to issue a certificate of the radon contamina-
tion before and after remedial work as well as the remedial
work that has been done.
The house owner should be informed that the success of
the remedial work should be regularly checked. This «con-
trol of effect» can be made by regular measurements (e.g.
every 3 to 5 years).
Sources:
1
Der Schweizerische Bundesrat, Strahlenschutzverordnung,
2013
2
Norm SIA 180, Wärmeschutz, Feuchteschutz und Raumklima
in Gebäuden, in Vernehmlassung
3
Norm SIA 380/1, Thermische Energie im Hochbau, 2009
4
Bundesamt für Gesundheit, Informationen für Bauherren zu
radonsichere Bauen, 2006
5
Bundesamt für Gesundheit, BAG-Empfehlungen: bauliche
Massnahmen für Neubauten und Sanierungen, 2012
6
Bundesamt für Gesundheit, Radon, Einfluss der energeti-
schen Sanierung, 2012
7
Bundesamt für Gesundheit, Radonhandbuch Schweiz, 2000
Fachvorträge / articles | 25

image
For the French population, exposure to radon is the prima-
ry source of exposure to ionizing radiation, before medical
exposure. Radon is a lung carcinogen for humans, classi-
fied in Group I in the classification of the International
Agency for Research on Cancer ( IARC). According to esti-
mates undertaken by the French Institute for Public Health
Surveillance (InVS), between 1200 and 2900 deaths from
lung cancer are attributable each year to indoor radon ex-
posure in France, which correspond between 5% and 12%
of deaths lung cancer observed in France.
These figures should be compared with estimates for other
risk factors. For example, for 1999, it was estimated that
approximately 2000 and 4200 lung cancer deaths were at-
tributable to occupational exposure to asbestos.
In France, the management of risk from radon exposure
into buildings started in 1999 with the first recommen-
dations for public buildings located in areas identified as
priorities.
Since 2004, the regulatory framework on the management
of the radon risk, fixed management methods in public
places such as schools, including buildings internship,
health and social institutions, spas and jails. The owners
of these establishments are obliged, when they are located
in one of the 31 priority departments, to make measure-
ments of radon activity concentration and, if necessary, to
implement the necessary measures to reduce the occupant
exposure.
Measurements of radon activity concentration are carried
out by bodies approved by the French Nuclear Safety Au-
thority (ASN).
In 2007, the management of the radon risk is extended to
workplaces. The Labour Code has introduced various im-
provements of existing rules protecting workers against
ionizing radiation from natural sources. It requires that,
in the underground workplaces where some defined acti-
vities are exercised, and situated in the priority areas, the
employer has to carry out measurements of radon activity
concentration by an approved body. The regulatory system
has been fully operational since late 2009.
Finally, a law dating from July 2009 completed the legis-
lative provisions of the Code of Public Health for the ma-
nagement of the radon risk in extending the requirement
to measure the radon activity concentration in other cate-
gories of buildings. The law should allow an extension of
the regulatory framework including residential buildings.
The decree law enforcement, in preparation, will include
the maximum level of radon activity concentration abo-
ve which it is necessary to reduce exposure to radon and
categories of buildings affected by these new provisions.
Also in line with the National Plan for Health and the En-
vironment (PNSE) and to meet the demand of European
Directive Euratom, France has developed National Plans of
Action against Radon. The first plan implemented (2005-
2008) allowed in the one hand, the implementation of
important measures for radon risk prevention and in the
other hand a close collaboration between the different ac-
tors involved in radon issue.
French experience in management and
research on the protection of building
with respect to radon
Bernard Collignan (CSTB, France)
DR Research Engineer
26 | Fachvorträge / articles
31 French priority departments
Currently, a second action plan is underway (PAR 2011-
2015). The plan developed is the result of collaboration
between the ASN and the Ministries of Housing, of Health
and of Labour, and with the support of public research
centers such as the Institute of Radioprotection and Nuc-
lear Safety (IRSN), the Scientific and Technical Center for
Building (CSTB), the InVS and organizations and regional
authorities.
The major focuses of the second plan are:
To establish a policy on radon risk management in
existing buildings for residential use,
To develop regulations for new buildings,
To follow the efficiency of the regulation stated for
existing public buildings and for working places.
To develop and to implement new management tools
and operating device for performing building diagno-
stics and construction work for building professionals
To coordinate policy studies and research
The Scientific and Technical Center for Building (CSTB) is
an independent French public institution dedicated to in-
novation into building. It is an industrial and commercial
public research center known in France as an EPIC. It is
placed under the joint supervision of Ministry of Housing
and the Ministry of Sustainable Development. It has a
workforce of around 950 employees. CSTB works on the
improvement of comfort and safety in buildings and their
environment in three complementary areas: research and
consultancy, quality evaluation and knowledge dissemina-
tion. CSTB fields of expertise are sustainable development,
safety and risk prevention, construction quality, structure
optimization, housing and urban development, informati-
on technology. CSTB has a long experience in dealing with
National and European activities and an research projects.
The Health and Buildings (HB) Division at CSTB has a staff
of 30 permanent (including 8 senior scientists). The HB di-
vision is dealing with research and consulting in the va-
rious fields interfacing buildings and health, and is more
particularly the technical and scientific coordinator of the
indoor air quality observatory (OQAI). It develops particu-
lar expertise in assessing the indoor air quality through
numerical and experimental research studies (laboratory,
experimental house, in situ).
Referring to radon risk into building, CSTB works for many
years in the building protection. CSTB provides scientific
and technical support to the government. It contributes to
various actions listed in the National Radon Action Plan.
It develops for many years expertise in the field of buil-
ding protection development and improvement through
standardization activities, applied research and supporting
actors of the building. It also participates in European ac-
tions on the subject.
Different field and experimental studies had been underta-
ken to ameliorate and asses the performances of building
protection systems:
Analysis of efficiency and cost of remedial actions in
existing buildings,
Test of feasibility of Soil Depressurization Systems
and dimensioning
Study on Passive Soil Depressurization System
Use of ventilation system to prevent radon income
Impact of thermal rehabilitation on radon exposure
Elaboration of a short term in-situ methodology to
assess radon potential in buildings
Main results of these studies will be summarized in this
presentation.
Some available publications on these subjects are listed
below.
Scientific Journals
- Radon remediation and prevention status in 23 European
countries. O. Holmgren; H. Arvela; B. Collignan; M. Jiranek; W.
Ringer. Radiation Protection Dosimetry 2013; doi: 10.1093/rpd/
nct156
- Development of a methodology to characterize radon entry
into dwellings. Collignan B., Lorkowski C., Améon R. Building
and Environment 57, 176 – 183, November 2012.
- Experimental study on passive Soil Depressurisation System
to prevent soil gaseous pollutants into building, Abdelouhab
M, Collignan B, Allard F. Building and Environment 45, 2400 –
2406, May 2010.
International conferences:
- Development of an air flow model for passive Soil Depressuri-
zation System design to protect building against radon. T.M.O.
Diallo, B. Collignan, F. Allard. 7th International Conference on
Protection Against Radon at Home and at Work. 2nd – 6th
Sept. 2013. Prague. Czech Republic.
- The Effect of New Building Concepts on Indoor Radon. W.
Ringer, J. Gräser, H. Arvela, O. Holmgren, B. Collignan. IRPA 13,
Glasgow, Scotland, 13 – 18 May 2012
- Basement Depressurisation using dwelling mechanical exhaust
ventilation system. Collignan B., O’Kelly P., Pilch E. 4th Euro-
pean Conference on Protection against radon at home and at
work. Praha, 28th june – 2nd july 2004.
- Dimensioning of soil depressurization system for radon
remediation in existing buildings. Collignan B., O’Kelly P.
Proceedings of ISIAQ 7th International Conference Healthy
Buildings 2003, Singapore, 7th – 11th December 2003, Vol. 1,
pp 517-523.
Fachvorträge / articles | 27

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28 | Fachvorträge / articles
Summary
In the paper experience in radon mitigation in Slovenia is
presented with the emphasis on different failure reasons.
Practical side of the mitigation is considered. Although the
paper does not deal with full description of different mi-
tigation systems employed general information on tech-
niques and their effectiveness is given. All employed sys-
tems are SSD (sub-slab depressurization) type. Cases with
unexpected results are also considered.
1. Introduction
History of systematic radon risk awareness and mitigation
in Slovenia is about 25 years long. Earlier radon research
and papers exist but they are limited to individual cases.
The approach effectively begun with 5 year national pro-
gram of measurements that included 730 kindergartens,
890 primary schools and 1000 apartments. Afterwards ad-
ditional measurements were done over time. The number
of schools is rather high – today there are 450 primary
schools registered in Slovenia, many have more than one
building. Thus one could claim virtually full coverage in
primary schools. On the other hand 1000 dwellings is a
respectable sample but it represents much smaller porti-
on of the full stock that comprises approximately 600.000
buildings – 500.000 of them being individual buildings.
Spatial distribution of higher risk is not uniform across
Slovenia due to different geological conditions. Karst ter-
rain presents higher risk and is found in southern Slovenia.
On the other hand individual buildings are smaller areas
are also identified with higher risk in cases where buil-
dings are built on compacted fly ash ground. These cases
are more seldom and are found mainly in vicinity of major
railway stations or in vicinity of steel factories.
2. Radon mitigation
Over the years ZAG has been involved in radon mitigation
in about 20 cases. Most of the cases were triggered by
alarmingly high measurements in schools found in previ-
ously mentioned study. As a rule average concentrations
before mitigation by far exceeded 1000 Bq/m
3
. Mitigation
was considered successful if concentrations after the mi-
tigation were less than 400 Bq/m
3
. In the following text
some interesting cases, important for understanding of
whole approach are described. The cases are summarized
in the Table 1 and are shown schematically on Figure 1
and Figure 2.
Radon mitigation in Slovenia
Friderik Knez, (ZAG Ljubljana
1
)
Figure 1: Schematic of different mitigation approaches (history cases) used in cases #1, #2 and #3.
1
Slovenian National Building and Civil Engineering Institute
Figure 2: Schematic of different mitigation approaches (new cases) used in cases #4, #5 and #6.
# Building
Basic building
description
Radon
source
CRn,initial
[Bq/m
3
]
CRn,inter
[Bq/m
3
]
CRn,mit
[Bq/m
3
]
Mitig.
[year]
Mitig.
principle
1
Jan
č
e
Wooden floor, fly-
ash in the structure.
Fly ash in the
floor structure
Over 1.000
less than 400
-
1997
SSD
2
Lokev pri Sežani
Wooden floor,
beneath large void
(estimated 1,5 m
3
/
m2 floor)
Soil
> 1.000
200-850
-
1997
New floor,
SSD
3
Dolenja vas
Concrete floor,
long shaft network
(piping, sewage)
Soil, radon
distributed by
shafts
600-4.150
100-3.165
< 100 - 500
1997
Ventilation
of shafts +
SSD (part)
4
Prevole
Concrete,
inaccessible walls
Soil
3.200
Not yet avail.
-
2012
SSD
5
Muljava
Concrete floor on
ground, under floor
suspected mixed
debris
Soil
4.000
380
-
2011
SSD
6
Vavta vas
Concrete (?), stone
walls, under floor
suspected debris
Soil
1.750
340
169
2013
SSD, sealing
Table 1: description of studied cases; C
Rn,initial
stands for average radon concentration before mitigation, C
Rn,inter
stands for average radon
concentration after first mitigation before correction and C
Rn,mit
stands for final mitigated average radon concentration. Exact values in
cases #1, #2 and #3 are incomplete.
Fachvorträge / articles | 29

3. History cases and new cases
Most of history cases are not very well documented. How-
ever common approach has been used in all mitigation ca-
ses form the first period. The cases are described in items
#1, #2 and #3 in Table 1. This approach was based on EPA
guidelines always involving a form, usually modified sub-
slab depressurization (SSD). In some cases SSD was assis-
ted by e.g. shaft ventilation. New cases are listed as cases
#4, #5 and #6.These have been executed recently.
Case #1
: the floor was old and incorporated loose fly-ash.
Some fly-ash was also in tampon layer as well. Lower part
of floor structure was wooden, permeable. In diagnostics
process pressure field extension was verified and estima-
ted as sufficient for SSD with 1 radon pit. The pressure
field was extended across whole school thanks to relatively
permeable tampon layer. The system employed was active,
piping through the old chimney to the roof. The ventilation
system was effective. Side effect of the system was sig-
nificantly drier wooden structure leading to minor wood
shrinkage and cracks.
Case #2:
the floor structure was wooden, inspection re-
vealed no pressure field extension and later large void in
contact with soil was found. In was decided that the floor
structure was not suitable for SSD thus new floor structure
was constructed with collector pipe system. Chimney was
used for vertical communication. The system was active,
however at first inadequate fan (bathroom type) was used
and later replaced with axial fan.
Case #3:
in radon concentration measurements it was es-
tablished that in main building radon originates from the
soil and is concentrated in shafts. It was also established
that this is by far most intensive route. Therefor ventilation
system for shafts was used and shaft lids were resealed or
closed permanently. In adjacent building radon was ente-
ring the rooms through concrete slab; SSD was executed in
that room and floor sealed with aluminum foil. While SSD
is proven successful and is still running the foil was proven
to be a bad choice due to moisture transport. Tight foil
caused floor swelling and was thus removed. Now system
is running as pure SSD system.
30 | Fachvorträge / articles
Case #4:
source of radon is soil (concentration of radon
in soil was measured over 100.000 Bq/m3. The floor struc-
ture is concrete, beneath the floor there is a layer of mixed
stone aggregate. Given the structure an SSD was designed
that would enter the aggregate layer horizontally. The SSD
system was supposed to be executed by local contractor.
However he failed to comply with the design and has
critically altered the design without consulting us, first.
Instead of a proper SSD system he has linked the layers
under the concrete slab with closed storage room in-front
of the wall. In these rooms originally piping should have
been be mounted. Then he has installed fans to ventilate
these rooms. Due to poor understanding of principles he
also created openings to allow for air-flow into the rooms.
The fans create some under-pressure in the closed storage
rooms but extension of the pressure field is very questio-
nable. Since the owner has already ordered measurements
of radon concentration it is decided to wait and see the
effect of the SSD, although predicted insufficient.
Case #5:
the floor structure is made of concrete. Under-
neath the structure soil was not known. Pressure field ex-
tension was extremely difficult to establish and is assumed
low. Nevertheless SSD was attempted as thin air layer was
expected just beneath the ground slab. The system was
properly executed by local contractor and measurements
have proven sufficient effect. The case is a proof that by
following the design SSD can work in almost all cases.
Case #6:
the floor structure is made of concrete. Part of
the building‘s walls exhibit wide crack in the target area of
mitigation. Selected mitigation strategy was SSD. To that
purpose a pilot system was installed in the cellar, accessing
the layer to be ventilated. The results however did not sup-
port the effectiveness. The reason is not known but men-
tioned crack might have short-circuited the depressuriza-
tion system. In order to resolve the issue another system
was installed, again accessing permeable layer. The system
on second spot was proven to be effective. However con-
centration in one room did not drop sufficiently. It is a
room directly above the cellar. Inspection has shown that
the floor is not tight enough. Because floor in cellar is not
suitable for SSD/SMD sealing with liquid waterproofing
system was proposed, but not yet done.
4. Follow-up
Lately there has been a follow-up activity to revisit mitiga-
ted sites. Some very valuable information was gained poin-
ting out some unexpected risks and difficulties in provision
of long-lasting solutions. These are described as follows.
Risk 1: unauthorized interventions: Common problem with
durability of radon mitigation solution is that in most
of the cases additional interventions were done. Most of
them are due to energy efficiency measures and due to ad-
aptation of building. None of such cases was verified with
original system designers. Due to lack of understanding of
the radon mitigation system this was either removed or
seriously hindered.
Risk 2:
failure to operate system properly: In case #2 the
radon mitigation system was properly executed. However
instructions for use were not respected. The system was
not operated continuously. The result was decrease of con-
centration with a phase-shift. Proper operation was again
explained to the staff.
Risk 3:
failure to comply fully with instructions for system
execution: In some cases (#3 and #4) the radon mitigation
system was improperly executed due to lack of understan-
ding of the purpose of individual components. The mecha-
nical engineer could not understand there is a need for
under-pressure but not for air-flow. The result: additional
openings close to the fan largely decreased under-pressure
field extension. The mitigation result was negative, the
concentrations remained virtually unchanged. After the
intervention and closing of the openings the concentra-
tions were measured again and were found at target level
of around 100 Bq/m
3
.
Risk 4:
users rely on mitigation system without further
measures: In case #6 the user of the building does not feel
any need for further considering concentration monito-
ring. He relies completely on set of system confirmation
measurements (not intended to establish radon concent-
ration relevantly), done in mitigation phase, which is not
appropriate.
5. Conclusion
It is essential that radon mitigation is done, if possible, in
one operation form measurement of radon concentration
to final mitigation system execution and verification. It
was clearly shown that the effectiveness of radon mitiga-
tion system in Slovenia largely depends on early involve-
ment of system installer, which is sometimes difficult due
to different reasons.
It is also essential that the system is monitored by profes-
sionals periodically and that clear warning is given against
any intervention in the building without consulting the ex-
perts. Although this might seem obvious and easy to do it
might not be easy after 10 or 20 years of operation of the
system. The same is true for operation of the system – edu-
cation on nature and use of the system is very important.
Thirdly – also surveillance by authorized body is necessary
in order to avoid shortcuts in execution or operation of
the system. This is especially true if awareness of radon
risk is low.
Finally – if properly executed relatively simple systems can
successfully mitigate radon.
References
[1] Radon and Real Estate, EPA,
http://www.epa.gov/radon/
realestate.html, accessed 23. 11. 2013
[2] Poročilo o stanju v okolju (2002), ARSO, 2002,
http://www.arso.
gov.si/, accessed 23. 11. 2013
Fachvorträge / articles | 31

image
32 | Fachvorträge / articles
Introduction
Elevated radon concentrations in indoor air are normally
caused by the convective flow of radon-bearing soil air.
Due to the high radon concentration in soil air, typically
10 000–100 000 Bq/m
3
, even very low leakage air flows of
0.1–1 m
3
/h (0.03–0.3 l/s) can raise indoor radon concent-
rations above the reference level of 200 Bq/m
3
.
Convective leakage flows are created by the indoor–out-
door pressure difference. Soil air flows into indoor spaces
through gaps, cracks and openings in the base floor. Two
mechanisms create the pressure difference: first, natural
forces such as the indoor–outdoor temperature difference
and wind, and second, forced mechanical ventilation. Ty-
pical pressure differences created by the indoor–outdoor
temperature difference range from 0–3 Pa (pascal).
Slab on ground is by far the most prevalent base-floor
type for newly-constructed low-rise residential houses in
Finland, accounting for 65% of houses. The key feature
of this base-floor type regarding radon prevention is the
gap between the floor slab and foundation wall (Figure 1).
This gap promotes the flow of radon-bearing soil air into
living spaces. When taking into account the leaking foun-
dations of semi-basement houses and basement houses,
altogether 80% of Finnish low-rise residential buildings
represent a foundation and base-floor type with a high
radon risk. Preventive measures in new construction are
thus an essential part of attempts to reduce radon concen-
trations in Finnish housing.
Regulations and guidance
The Finnish building code for radon prevention and the as-
sociated practical guidelines were revised in 2003 to 2004
(Building Information Ltd. 2003, Ministry of environment
2004). In the building code it is written that “In the design
and construction work, radon risks at the construction site
shall be taken into account.” The indoor radon concentra-
tion must be below 200 Bq/m
3
. A radon-technical design
may be left out only in case the local radon surveys clearly
show that the radon concentration inside residential buil-
dings is consistently below the permitted maximum value.
To study the effect of the new regulations, STUK carried
out a random sample survey of new construction in 2009
(Arvela et al. 2012).
Finnish experiences in radon prevention
in new construction and energy saving
constructions
Olli Holmgren and Hannu Arvela
Radiation and Nuclear Safety Authority – STUK, P.O. Box 14, 00881 Helsinki, Finland
The revised guidance for radon-resistant new construction
focuses on practices needed in houses with slab on ground
as well as in houses with walls in contact with soil. The
preventive measures include a radon piping (a network of
perforated drainage pipe) installed below the floor slab
and sealing of the joint between the floor slab and the
foundation wall using a strip of bitumen felt (Figure 1).
The discharge of the radon piping is lead open above roof.
The temperature difference and wind create an air flow to
the exhaust duct, which reduces the radon concentration
in the pore air of the sub-slab gravel. When needed, one
can install a fan on the exhaust duct which, when active,
effectively reduces the indoor radon concentration.
Energy saving construction
The new practices of low-energy construction require
improved thermal insulation, high air tightness and the
implementation of mechanical supply and exhaust venti-
lation (MSEV) with heat recovery. Practically all new cons-
truction in Finland is presently provided with MSEV due to
the demands for energy conservation. Simultaneously, the
air tightness of newly build houses has been increasing,
typical ACH50 values being already 1–4 h
-1
. However, the
number of actual passive houses is still small in Finland.
The effect of air tightness and pressure differences on the
indoor radon concentration in houses with different ven-
tilation strategies have been studied in detail in (Arvela et
al. 2013) through calculations, modelling and experimental
studies.
Results
Based on the new construction survey, the average radon
concentration of new houses, completed in 2006 to 2008,
was 95 Bq/m
3
, the median being 58 Bq/m
3
, Table 1. The
average was 33% lower than in houses completed in 2000
to 2005. The decrease was 47% in those provinces with the
highest indoor radon concentrations and 26% elsewhere
in the country. The decrease compared to houses comple-
ted in 1980 to 1999 was more than 40%, Figure 2. The
percentage of houses exceeding the reference level of 200
Bq/m
3
had also markedly decreased, from 16% to 11%. In
high radon provinces, the percentage was decreased from
42 % to 16.5 %.
Radon concentrations were by far the lowest in houses
with a reinforced uniform floor slab and those with a
crawl space. In both of these classes, the average radon
concentration was below 45 Bq/m
3
and the median below
30 Bq/m
3
. In houses with a slab on ground, the average
was 96 Bq/m
3
and the median 68 Bq/m
3
. In semi-basement
and basement houses with block walls in contact with
soil, the average and the median were 151 Bq/m
3
and 100
Bq/m
3
, more than 50% higher than in houses with a slab
on ground. The main reason for these elevated values is
the defective measures for radon prevention in the block
walls made of lightweight aggregate concrete. Leakages of
radon-bearing soil air through the block walls in contact
with soil can also be seen in the percentage of houses ex-
ceeding the reference level of 200 Bq/m
3
. This figure was
22 %, as compared to 11 % for single family houses with
slab on ground.
Preventive measures had been carried out in 54% of single
family houses with slab on ground. The percentage was
92% in the six provinces with the highest indoor radon
concentration (Zone 1) and 38% elsewhere in the country
(Zone 2 in Table 1). Nationwide, the new regulations issu-
ed in 2003 to 2004 have doubled the level of prevention
activity.
The effectiveness of preventive measures was assessed
through a comparison of indoor radon concentrations
in houses with prevention compared to those where no
preventive measures had been taken. In this comparison,
local reference values from the indoor radon database, in-
Figure 1. Sealing of the gap between the foundation wall and floor slab, and installation
cluding 87 000 houses throughout Finland (Valmari et al.
of radon piping according to the Finnish radon prevention guidelines. Image from RT
81–11099 (Building Information Ltd).
Fachvorträge / articles | 33

image
34 | Fachvorträge / articles
2010), were utilized. The details can be found in (Arvela et
al. 2012). In single family houses with slab on ground, pas-
sive radon piping and the installation of a strip of bitumen
felt reduced the indoor radon concentration by 55%. The
average reduction for radon piping with no sealing mea-
sures was 40%.
The effect of ventilation strategies on radon concentration
was examined using the STUK’s radon measurement data-
base (Arvela et al. 2013). The data for houses constructed
in 1985–1994 was used in order to obtain a homogeneous
data set. Radon concentration in total of 5312 houses was
analysed. The result was such that the use of MSEV re-
duced radon by 30 % compared to houses with natural
ventilation.
MSEV makes it possible to control the pressure difference
using balanced ventilation. In practice, in countries where
fully balanced ventilation is recommended, slight positive
or negative pressures (i.e. unbalance) exist in living spaces
due to inaccuracies and variation in air flow adjustments
and measurements. The results of our study (Arvela et al.
2013) indicate that in an airtight MSEV house with ACH50
<1 h
-1
, pressure differences from 1–10 Pa may occur when
10 % difference between supply and exhaust air exists.
When the typical natural pressure differences due to the
indoor–outdoor temperature difference are 1–3 Pa, these
additional pressure differences created by the ventilation
system and high air tightness markedly increase the flow
of radon-bearing soil air into living spaces if there are any
gaps in the base floor.
Conclusions
According to the results of the new construction sur-
vey, there is high variation in the prevention activity in
different areas of the country. Local authorities require
prevention measures commonly in those areas with the
highest radon concentrations, which has also resulted in
a considerable decrease in indoor radon concentrations.
On the other hand, in those areas where no prevention
has been taken, indoor radon concentrations have remai-
ned as before or have even increased. Radon-resistant new
construction practices represent economic investments.
The effect of preventive measures is so significant that
installation of the passive radon piping and bitumen felt
is recommended throughout the country. Builders should
require architects and all participants in building projects
to implement radon prevention measures according to the
current guidelines. After completion of the new house, it
is important to measure the radon concentration to con-
firm the low radon level. If radon concentration is above
the reference level, it is easy to activate the radon piping
with a fan.
Table 1:
Average and median radon concentration and
percentage of houses exceeding 200 Bq/m
3
in the new
construction survey (2009) for the six provinces of Finland
with the highest radon concentration (Zone 1) and else-
where in the country (Zone 2). Comparison with the win-
ter measurement of the nationwide sample survey (2006)
(Mäkeläinen et al. 2010).
The requirement for radon prevention in connection with
the application for building permission and the wides-
pread and skilled implementation of preventive measures
throughout the country could result in an average of 50%
reduction in indoor radon concentrations compared to
the present housing stock with no prevention. This would
considerably reduce exposure to radon and the harmful
health effects of indoor radon in the coming decades.
The aims towards high air tightness are synergetic for ra-
don prevention and low energy construction: the base floor
and foundation constructions should be carefully sealed.
On the other hand, due to the interaction of mechanical
ventilation and high air tightness, the pressure difference
in buildings can be markedly enhanced in some cases. This
may lead to elevated indoor radon levels if there are minor
leakages in the base floor. The minor leakages can affect
the radon concentration, even in cases where the leaks do
not markedly reduce the total air tightness. The potential
for high negative pressures considerably increases when
the air tightness ACH50 is below 1.0 h
-1
. This is a challenge
for efficient radon prevention in new construction. Guide-
lines for ventilation adjustment in MSEV houses may also
need revision.
Radon concentration (Decrease in levels in the new construction survey, compared
with the sample survey (2006), % or percentage points, pp)
New construction survey (2009)
Sample survey (2006), winter meas.
Survey and region
Average
Bq/m
3
Median
Bq/m
3
Percentage
>200 Bq/m
3
Average
Bq/m
3
Median
Bq/m
3
Percentage
>200 Bq/m
3
Zone 1
125 (47%)
74 (55%)
16.5 (25 pp)
237
166
41.9
Zone 2
83 (26%)
53 (28%)
8.4 (3.8 pp)
112
74
12.2
Whole country
95 (33%)
58 (33%)
10.6 (8.8 pp)
142
87
19.4
Zone 1: Provinces of Itä-Uusimaa, Kymenlaakso, Päijät-Häme, Pirkanmaa, Etelä-Karjala and Kanta-Häme;
Zone 2: Other provinces
Figure 2. Radon concentration in low-rise residential houses according to the year of
construction based on the national Finnish sample survey in 2006 (1949–2005). The last
bar (2006–2008) represents the results of the new construction survey (2009).
References
– Arvela H., Holmgren O., Reisbacka H. (2012) Radon prevention
in new construction in Finland: A Nationwide sample survey
in 2009. Radiation Protection Dosimetry (2012), 148 (4): 465-
474; doi: 10.1093/rpd/ncr192.
– Arvela, H., Holmgren, O., Reisbacka, H. and Vinha, J. (2013)
Review of low-energy construction, air tightness, ventilation
strategies and indoor radon: results from Finnish houses
and apartments. Radiation Protection Dosimetry 2013,
doi:10.1093/rpd/nct278.
– Building Information Ltd. (2003) Radon Prevention, RT
81–11099 (LVI 37–10513). Helsinki (2003). (In Finnish)
– Ministry of Environment. (2004) Foundations, Regulations and
Guidelines 2004. The National Building Code of Finland. Part
B3. Helsinki (2004).
– Mäkeläinen I, Valmari T, Reisbacka H, Kinnunen T, Arvela H.
(2011) Indoor Radon and Construction Practices of Finnish
homes from 20th to 21st century. Proceedings of the third
European IRPA congress, 14-18 June 2010, Helsinki, Finland,
pp 561-569. STUK/NSFS, electronic publication 2011.
– Valmari, T., Mäkeläinen, I., Reisbacka, H. and Arvela, H. Suo-
men radonkartasto 2010. Radonatlas över Finland 2010. Radon
Atlas of Finland 2010. Report STUK-A245. Radiation and Nuc-
lear Safety Authority. Helsinki 2010. ISBN 978-952-478-537-2.
www.stuk.fi.
Fachvorträge / articles | 35

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36 | Fachvorträge / articles
In diesem Artikel zur Baupraxis betreffend Radon in Öster-
reich werden folgende Themenbereiche beleuchtet:
Baugesetzliche Rahmenbedingungen
Bautechnische Grundlagen
Erfahrungen und Ausblick
Baugesetzliche Rahmenbedingungen
Das Baurecht in Österreich befindet sich im Kompetenz-
bereich der neun österreichischen Bundesländer. Daraus
ergibt sich die Situation, dass bei einer Einwohnerzahl
von rund 8,5 Millionen neun verschiedene Baugesetze mit
jeweils von einander abweichendem Verfahrensrecht und
ebenso abweichenden bautechnischen Bestimmungen ne-
beneinander stehen können.
Beginnend ab 1948 wurde mehrfach der Versuch unter-
nommen, insbesondere für die bautechnischen Bestim-
mungen eine Harmonisierung (Vereinheitlichung) in Ös-
terreich herbeizuführen. Erst im April 2007 führten diese
Bestrebungen erstmals zu einem Erfolg, nämlich als sechs
bautechnische Richtlinien, die sogenannten OIB
1
-Richtli-
nien, als ein harmonisiertes bautechnisches Regelwerk ver-
öffentlicht wurden. Diese OIB-Richtlinien dienen als Basis
für die Harmonisierung der bautechnischen Vorschriften in
den österreichischen Bundesländern und können von die-
sen freiwillig zu diesem Zweck herangezogen werden. Die
Erklärung einer rechtlichen Verbindlichkeit der OIB-Richt-
linien ist den Bundesländern vorbehalten. Zwischenzeitlich
haben sieben von neun Bundesländern die OIB-Richtlinien
als bautechnische Bestimmungen in das jeweilige Baurecht
übernommen und haben damit dem Harmonisierungsge-
danken Rechnung getragen (Vorarlberg, Tirol, Kärnten,
Steiermark, Burgenland, Wien und Oberösterreich). Le-
diglich die Bundesländer Niederösterreich und Salzburg
haben ihre eigenen, landesspezifischen bautechnischen
Bestimmungen beibehalten.
Dieser Entwicklungsprozess ist für das Thema des bauli-
chen Radonschutzes von besonderer Relevanz, da in den
OIB-Richtlinien erstmals Bestimmungen zur bautechni-
schen Radon-Vorsorge enthalten sind. So wird in der OIB-
Richltinie 3 betreffend Hygiene, Gesundheit und Umwelt-
schutz, Stand Oktober 2011, in Pkt. 8.2 folgendes geregelt:
„Aufenthaltsräume sind so auszuführen, dass keine die
Gesundheit der Benützer beeinträchtigende ionisierende
Strahlung aus Baumaterialien und Radonemission aus dem
Untergrund auftritt. Hinsichtlich der ionisierenden Strah-
lung aus Baumaterialien gilt dies jedenfalls als erfüllt,
wenn Bauprodukte bestimmungsgemäß verwendet werden,
die die landesrechtlichen Vorschriften über Bauprodukte
erfüllen.“
In jenen sieben österreichischen Bundesländern, die die
OIB-Richtlinien als bautechnische Bestimmungen in die
Baugesetzgebung übernommen haben, ist die oben an-
geführte Bestimmung betreffend Radon rechtsverbindlich
einzuhalten. Die angeführten Anforderungen bezüglich
eines baulichen Radonschutzes gelten grundsätzlich für
Neubauten und auch Nutzungsänderungen, nicht aber für
Bestandsbauten. Zur Klärung der Frage, wie ein baulicher
Radonschutz nach der obigen Bestimmungen auszusehen
hat, ist in Österreich auf bautechnische Regelwerke wie
zum Beispiel die ÖNORMEN-Serie S 5280 zurückzugreifen.
Darauf wird im folgenden Kapitel „Bautechnische Grund-
lagen“ näher eingegangen.
Bautechnische Grundlagen
Bereits seit mehr als zehn Jahren exisitiert die ÖNORMEN-
Serie S 5280
2
mit dem Titel „Radon“. Diese Normenserie
gliedert sich derzeit in drei Teile:
Teil 1:
Messverfahren und deren Anwendungsbereiche
(Ausgabe 2008-05-01)
Teil 2:
Technische Vorsorgemaßnahmen bei Gebäuden
(Ausgabe 2012-07-15)
Teil 3:
Sanierungsmaßnahmen an Gebäuden (VORNORM
– Ausgabe 2005-06-01)
Aus bautechnischer Sicht sind insbesondere Teil 2 und Teil
3 von Interesse.
Baupraxis betreffend Radon in Österreich –
Regelungen, Erfahrungen und
Zukunftsausblick
Dipl.-Ing. Julia Karimi-Auer
Amt der Steiermärkischen Landesregierung Abteilung 15 - Energie, Wohnbau, Technik,
Fachabteilung Energie und Wohnbau, Graz
In Teil 2 werden Maßnahmen bei Neubauten in Abhängig-
keit der Radonpotentialklasse geregelt. Die Regelung er-
folgt über ein einfach abzuarbeitendes Flussdiagramm, das
im Wesentlichen folgenden Schluss zulässt:
Zusätzlich zu einer dem Stand der Technik entsprechenden
Bauwerksabdichtung gegen Feuchtigkeit und Wasser als
stets anzuwendende und ausreichende Grundmaßnahme
sind in folgenden Fällen Maßnahmen erforderlich:
Gebäude verfügt über kein baulich abgetrenntes
Kellergeschoß oder keinen belüfteten Kriechkeller
Aufenthaltsräume befinden sich im Keller
Bauwerk liegt in der Radonpotentialklasse 2 oder 3
(d.h. Radonpotential der Gemeinde mindestens 200
Bq/m³)
Die erweiterten Maßnahmen zur baulichen Radonvorsorge
sind in der ÖNORM S 5280-2, Radon - Teil 2: Technische
Vorsorgemaßnahmen bei Gebäuden, beschrieben (z.B. Aus-
führung einer Unterbodenabsaugung / Radondrainage).
Die Wirksamkeit von getroffenen, baulichen Vorsorgemaß-
nahmen sollte bei einem Radonpotential der Gemeinde
von 200 Bq/m³ und mehr nach Ausführung der jeweiligen
Maßnahme durch Radon-Messungen überprüft und bestä-
tigt werden.
Bezüglich baulicher Maßnahmen für den Radonschutz in
Bestandsbauten wird auf den Teil 3 der Normenserie ver-
wiesen. Dieser Normenteil liegt derzeit noch als Vornorm
auf und soll 2015 neu aufgelegt werden. Zur baulichen
Radonsanierung nennt die Norm zehn verschiedene Me-
thoden, die weitgehend auf Erfahrungen beruhen, die im
Rahmen von nationalen Radon-Programmen in Österreich,
den USA, Kanada, Schweden, Finnland, Großbritannien, der
Schweiz, Südtirol und Deutschland gesammelt wurden. Bei
diesen zehn Methoden handelt es sich um:
Unterbindung des konvektiven Luftstroms zwischen
Keller und den darüberliegenden Räumen
Reduktion des infolge des Kamineffekts herrschenden
Unterdrucks im Gebäude
Erhöhte natürliche Belüftung unterhalb der Boden-
platte
Unterbodenabsaugung (siehe auch Bild 1 und Bild 2)
Mechanische Belüftung des Gebäudes
Zwischenbodenabsaugung
Erzeugung von Überdruck im Gebäude (Kellerge-
schoß)
Verfugung von Öffnungen, Rissen und Spalten bzw.
Versiegelung von Flächen durch Anstriche oder Be-
schichtungen
Abschirmung des Untergrundes durch Injektions-
schirme
Darüber hinaus beschreibt die Vornorm ÖNORM S 5280-3
detailliert, wie bei einer baulichen Radon-Sanierung vor-
zugehen ist (notwendige Erhebungen, Messungen und
Maßnahmen).
1
Slovenian National Building and Civil Engineering Institute
2
Bezug beim Österreichischen Normungsinstitut (ON), Heinestraße 38, 1020 Wien
Rohrführung im Rahmen einer Unterbodenabsaugung über einen stillgelegten
Abgasfang (Radonsanierung in einem Privathaus)
Fachvorträge / articles | 37

image
38 | Fachvorträge / articles
Fachvorträge | 39
3
Österreichische Agentur für Gesundheit und Ernährungssicherheit (AGES), Wieningerstrasse 8, 4020 Linz
Erfahrungen und Ausblick
Das Bundesland Oberösterreich, das bereits seit dem Jahr
1997 sowohl Radonsanierungen als auch Maßnahmen zum
radonsicheren Bauen bei Neubauten finanziell fördert,
nimmt diesbezüglich in Österreich eine Vorreiterrolle ein.
Im Rahmen dieser Radonförderungen wurden in Oberös-
terreich seit dem Jahr 1997 67 Neubauförderungen und
55 Bestandsförderungen durchgeführt. Bei Bestandssa-
nierungen wurde vielfach und erfolgreich die Methode
der Unterbodenabsaugung angewandt, sodass im Rahmen
dessen entsprechende Erfahrungen gewonnen werden
konnten. Diese Erfahrungswerte werden in Zukunft ausge-
baut werden können, da das radonsichere Bauen für Neu-
bauten in Österreich nun fast flächendeckend gesetzlich
vorgeschrieben ist. Um diese neuen und bisher nicht dage-
wesenen Regelungen betreffend radonsicherem Bauen in
der baubehördlichen Bewilligungspraxis zu verankern, wird
dieses Thema in Rahmen von Schulungen für Bausachver-
ständige vorgetragen.
Weitere Erfahrungen sind aus dem derzeit im Bundes-
land Steiermark laufenden Radon-Projekt zu erwarten. Bei
diesem in Zusammenarbeit zwischen der AGES
3
und dem
Amt der Steiermärkischen Landesregierung abgewickelten
Projekt wurden in drei Gemeinden der Steiermark Radon-
Messungen in rund 1000 Haushalten durchgeführt. Auf
Basis der ausgewerteten Messergebnisse wird auch in der
Steiermark eine finanzielle Förderung für Radonsanierun-
gen eingerichtet werden.
Weiterführende Informationen
– OIB-Richtlinie 3 „Hygiene, Gesundheit und Umweltschutz“
betreffend baulichen Radonschutz:
www.oib.or.at
– Allgemeine Informationen zu radonsicherem Bauen im
Bundesland Oberösterreich:
www.land-oberoesterreich.gv.at/
thema/radon
– Bezug der ÖNORMEN-Serie S 5280 (Teil 1-3):
www.on-norm.at
– Österreichweite Abfrage des Radonpotentials auf Gemeinde-
basis:
www.radon.gv.at/radonsuche.html
– Allgemeine Informationen des Bundesministerium für Land-
und Forstwirtschaft, Umwelt und Wasserwirtschaft:
www.lebensministerium.at/umwelt/strahlen-atom/strahlen-
schutz/radon/radonpotenzial.html
– Rechtsinformationssystem des Bundes:
www.ris.bka.gv.at
Über die Autorin
Julia Karimi-Auer hat das Studium des Bauingenieurwesens an
der Technischen Universität in Graz abgeschlossen und danach
etliche Jahre als Statikerin im Hoch- und Tiefbau sowie Projekt-
leiterin im konstruktiven Wasserbau (Wasserkraftwerksplanung)
gearbeitet. Seit 2005 ist sie als bautechnische Amtssachverstän-
dige und Referentin für bautechnische Fragen beim Amt der
Steiermärkischen Landesregierung / Österreich tätig.
Kontakt: julia.karimi-auer@stmk.gv.at
Die Fotos stammen von der Autorin.
Rohrführung im Rahmen einer Unterbodenabsaugung über einen stillgelegten
Abgasfang (Radonsanierung in einem Privathaus)

40 | Fachvorträge / articles
Introduction
The Italian National Radon Action Plan (INRAP) was pre-
pared in 2002 by a working group of several experts and
approved by the Ministry of Health. Its implementation
started on 2005. The approach of the INRAP as regards
prevention in new buildings and mitigation in existing
buildings evolved from the original text of 2002, taking
into account some main results of recent epidemiologi-
cal studies, recommendations of the European project
RADPAR (Radon Prevention and Remediation) (Bartzis et
al, 2012), as well as approaches included in recent/forth-
coming national and international regulations, including
the WHO Handbook on Indoor Radon (WHO, 2009) and the
European Directive on Basic Safety Standards which is ex-
pected to be approved in the next few months.
As regards the recent epidemiological studies on radon
exposure in dwellings and in mines, the main results are
the followings: i) a statistically significant increased risk
of lung cancer can be observed for long-term exposures to
relatively low values of radon concentration, i.e. for values
not greater than 200 Bq/m3, which are relatively common
in dwellings and workplaces (Darby et al, 2005); ii) the risk/
exposure data are well described by a linear-no threshold
function, and other functions (including function with a
threshold) do not improve the data fit (Darby et al, 2005);
the risk of lung cancer evaluated on the basis of recent
epidemiological studies in mines resulted to be about two
times higher than previous evaluations by ICRP which
were the basis of international and national regulations up
to few years ago (Tomasek et al, 2008).
As regards international and national recommendations
and policies on radon, all the most recent ones (starting
from the WHO Handbook on Indoor Radon, published in
2009) tend to require a higher protection of population
and workers (Bochicchio, 2011), not limited to radon-prone
areas, and to adopt lower reference levels for radon con-
centration.
The Italian National Action Plan and preventive measures
in new buildings
The approach chosen within the INRAP as regards the pre-
ventive measures in new buildings is strongly related to
the main long-term goal of the INRAP, which is the re-
duction of the health burden related to radon exposure.
Moreover, it takes into account the elements reported in
the Introduction.
On these basis it was decided that preventive measures
– to reduce the ingress of radon from soil and to facili-
tate installation of post-construction systems to further
reduce radon concentration – should be introduced in all
the new buildings, contrary to the alternative approach
to do it in selected areas only (i.e. in radon-prone areas),
in order to maximize the radon health burden reduction.
This approach has also a favorable cost-effectiveness. As a
clear consequence of this approach, preventive measures
should be introduced also in case of considerable building
renewals involving soil-building interface.
In order to make this approach feasible in a large number
of buildings, it is very important that the chosen preven-
tive measures are not expensive and easy to be applied,
i.e. not requiring training or specific knowledge on radon.
The approach of the Italian National
Action Plan on radon for prevention in new
buildings and mitigation in existing buildings
and considerations on the effects of the
forthcoming new European Directive
Francesco Bochicchio (ISS, Italy)
on behalf of the Working Group of the Italian National Radon Action Plan on Preventive
Measures and Remedial Actions against Indoor Radon*
These contents were included in 2008 in a specific re-
commendation on this issue approved by the Scientific
Committee of the Italian National Radon Action Plan (SC-
INRAP, 2008). A similar recommendation was given in UK
some months before the Italian one, also considering cost-
effectiveness evaluation (UK-HPA, 2008).
This recommendation is intended to be formally imple-
mented in regional building regulations and local building
codes, and several Italian Regions and Municipalities has
already adopted it, although a uniform adoption in Italy
has to be obtained, yet. Such uniform adoption will proba-
bly result from the transposition of the forthcoming Euro-
pean Directive into the Italian national legislation, howe-
ver it could be anticipated in the next few years.
In order to facilitate the implementation of the SC-INRAP
recommendation, a guideline has been prepared by a wor-
king group within the framework of INRAP. This guideline,
which is going to be published, contains eight cards/sche-
mes, corresponding to the eight typical situations resulted
from a classification of the building type in terms of pre-
sence of a crawl space (two options: yes/not) and in terms
of position of the lowest rooms respect the ground level
(four options: building with underground rooms; building
with partially underground rooms, i.e. with basement;
building with lowest rooms at ground level, and building
lowest rooms above ground level).
Each card/scheme illustrates basic recommendations with
the support of some drawings.
The basic goals of the illustrated preventive measures are:
i) reduce the ingress of radon from soil, ii) facilitate ins-
tallation of post-construction systems to further reduce
radon concentration. The first goal is reached by means
of both a barrier (a low-permeability membrane) installed
below the lowest floor of the building and a passive venti-
lation system installed in the crawl space (if it is present)
or in the sub-soil. The second goal is reached by preparing
connections of the above cited ventilation system to an
active pump. Therefore each card/scheme illustrates two
passive systems (a membrane + passive ventilation sys-
tem) to reduce radon in every new building, as well as the
position of the pump to be connected to the (crawl space
or sub-soil) ventilation system in case, after construction,
radon concentration needs to be further reduced.
As regards membranes, normal membranes (i.e. not spe-
cific for radon) are recommended, provided they have an
adequate thickness and allow a good sealing.
The Italian National Action Plan and mitigation in existing
buildings
As regards mitigation in existing buildings, at present the-
re is no specific approach adopted in Italy.
A regulation is on force in Italy only for underground
rooms of workplaces (including schools), so that most of
the mitigated buildings are actually workplaces, typically
schools. Moreover, the action level for workplaces in the
current Italian regulation is 500 Bq/m3, so that the esti-
mated number of workplaces with radon concentration
exceeding the action level is relatively low.
However, the forthcoming European Directive on Basic
Safety Standards will require that Member States adopt
a maximum reference level of 300 Bq/m3 for both work-
places and dwellings, so that a much higher number of
buildings are estimated to need mitigation in order to re-
duce radon concentration below the reference level that
Italy will decide to adopt.
It could be difficult to develop a network of local building
professionals trained and qualified in radon mitigation. In
such cases, similarly to the approach adopted for preven-
tive measures, the “normal” building professionals should
be used also for radon remedial actions, provided that they
receive operative instructions from professionals qualified
in radon mitigation.
1
Slovenian National Building and Civil Engineering Institute
2
Bezug beim Österreichischen Normungsinstitut (ON), Heinestraße 38, 1020 Wien
Fachvorträge / articles | 41

42 | Fachvorträge / articles
Some considerations on the effects of the forthcoming
new European Directive
The forthcoming new Directive will represent a unique in-
strument to strongly improve the protection from radon in
European countries. It is the first time that protection from
radon in dwellings in included in an European directive
– which has to be transposed into national legislation of
Member States – and requirements on radon in workplaces
have also significantly increased. Some flexibility has been
introduced in the directive in order to allow Member States
to take into account national circumstances. However, a
transposition more protective than the basic safety stan-
dards is possible, as clearly specified in the directive.
It is desirable that transposition will occur (within the next
four years, as required by the directive) at the highest pro-
tective level possible. Therefore, the experience gained in
several countries should be used to the maximum extend.
The recommendations produced within the RADPAR pro-
ject (Bartzis et al, 2012), which resulted from an elaborati-
on of such experience discussed among several European
countries, could be a useful tool.
* Composition of the Working Group of the Italian National
Radon Action Plan on Preventive Measures and Remedial
Actions against Indoor Radon
The WG is composed by both radon and building experts.
In the first phase the following persons contributed to the
WG: G. Torri (ISPRA, Roma, Italy) coordinator of the WG,
F. Bochicchio (ISS, Roma, Italy) coordinator of the INRAP,
C. Giovani (ARPA Friuli-Venezia Giulia, Italy), S. Innamorati
(ISS, Roma, Italy), L. Minach (APPA Bolzano, Italy), A. Ste-
fano (ISS, Roma, Italy), R. Trevisi (ISPESL, Roma, Italy), G.
Zannoni (Univ. Ferrara, Italy).
In a second phase the following persons contributed to
the WG: F. Bochicchio (ISS, Roma, Italy), S. Bucci (ARPA
Toscana, Firenze, Italy), A. Stefano (ISS, Roma, Italy), M. Ci-
uffreda (Roma Municipality, Italy), C. Succhiarelli (Roma
Municipality, Italy), C. Alimonti (Roma Municipality, Italy).
References
Bartzis J, Arvela H, Bochicchio F, Bradley J, Colligan B, Fenton
D, Fojtikova I, Gray A, Grosche B, Gruson M, Holmgren O, Hul-
ka J, Jiranek M, Kalimeri K, Kephalopoulos S, Klerkx J, Kreuzer M,
McLaughlin J, Mueller S, Ringer W, Rovenska K, Schlesinger D, Ve-
noso G, Zeeb H (2012). The RADPAR Recommendations. Report
of the European project RADPAR (Radon Prevention and Reme-
diation), 27 pp (available at
http://web.jrc.ec.europa.eu/radpar/
documents.cfm).
Bochicchio F. (2011) The newest international trend about regula-
tion of indoor radon. Radiat Prot Dosim 146 (1–3): 2–5.
Darby S, Hill D, Auvinen A, Barros-Dios JM, Baysson H, Bochic-
chio F, Deo H, Falk R, Forastiere F, Hakama M, Heid I, Kreienbrock
L, Kreuzer M, Lagarde F, Mäkeläinen I, Muirhead C, Oberaigner W,
Pershagen G, Ruano-Ravina A, Ruosteenoja E, Schaffrath Rosario
A, Tirmarche M, Tomáček L, Whitley E, Wichmann HE, Doll R. (2005)
Radon in homes and lung cancer risk: collaborative analysis of
individual data from 13 European case-control studies. BMJ 330:
223–226.
EC (European Commission) (2013). Proposal for a Council Directi-
ve laying down basic safety standards for protection against the
dangers arising from exposure to ionising radiation. (A version
close to the expected final version can be found at the documents
repository of the European Council,
http://register.consilium.euro-
pa.eu/pdf/en/13/st08/st08682-re02.en13.pdf)
SC-INRAP (Scientific Committee of the Italian National Radon Ac-
tion Plan) (2008). Recommendation on radon protective measures
in all new buildings (in Italian). Available at
www.iss.it/binary/tesa/
cont/PNR_Raccomandazione.pdf.
Tomasek L., Rogel A., Tirmarche M., Mitton N., Laurier D. (2008)
Lung cancer in French and Czech uranium miners: radon-associa-
ted risk at low exposure rates and modifying effects of time since
exposure and age at exposure. Radiat. Res. 169(2), 125–137.
UK-HPA (United Kingdom-Health Protection Agency) (2008). HPA
advice on radon protective measures in new buildings. 21 May.
WHO (World Health Organization) (2009). WHO Handbook on In-
door Radon: A Public Health Perspective. Geneve.

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44 | Fachvorträge / articles
Hintergrund zu den Entwicklungen
Im Jahr 2008 entwickelte das Bundesministerium für Ver-
kehr, Bau und Stadtentwicklung (BMVBS) in Kooperation
mit der Deutschen Gesellschaft für Nachhaltiges Bauen
(DGNB), einen ersten nationalen Satz an Nachhaltigkeits-
kriterien zum Ziele der transparenten sowie ganzheitlichen
Bewertung von Gebäuden. Die Systementwicklung folgte
dabei den aktuellsten Entwicklungen der europäischen
Nachhaltigkeitsnormung und integrierte neben den we-
sentlichen drei Säulen der Nachhaltigkeit zusätzlich tech-
nische und prozessuale Fragen in insgesamt fünf Haupt-
kriteriengruppen.
Das aktuelle System umfasst für die Neubaubewertung
insgesamt 40 Kriterien zur Bewertung der Gebäudequa-
lität und sechs Kriterien zur Beschreibung der Standort-
merkmale, darüber hinaus steht die Berücksichtigung des
Gebäudelebenszyklus im Vordergrund.
Berücksichtigung von Radon im
Bewertungssystem Nachhaltiges Bauen
Dipl. Ing. Nicolas Kerz
Bundesinstitut für Bau-, Stadt- und Raumforschung
Referat II 5 Nachhaltiges Bauen
In Adaption der gemeinsamen Arbeitsergebnisse, pflegt
das BMVBS seit dem Jahre 2009 das Bewertungssystem
Nachhaltiges Bauen (BNB) für Bundesgebäude (Abb.2).
Entsprechend der aktuellen Erlasslage des BMVBS, ist der
Leitfaden Nachhaltiges Bauen (Abb. 3) und damit verbun-
den das BNB als erforderliche Nachweismethodik für den
zivilen Hochbau des Bundes verbindlich eingeführt wor-
den. Für Verwaltungsneubauten, Unterrichtsneubauten so-
wie Komplettmodernisierungen von Verwaltungsgebäuden
ab einer Investitionssumme von 2 Mio. Euro gilt, dass eine
Gebäudebewertung mit abschließender Konformitätsprü-
fung im Mindeststandard Silber umzusetzen ist.
Derzeitige Adressierung von Radon im BNB
Wie können Gebäudebewertungssysteme wie das Bewer-
tungssystem Nachhaltiges Bauen bei der Reduktion von
Schadstoffen im Gebäude im Allgemeinen und im Spe-
ziellen bei geogenem Radon dienlich sein?
Das Bewertungssystem Nachhaltiges Bauen verfolgt das
primäre Ziel, das Baugeschehen in seiner Ganzheitlichkeit
„messbar“ hinsichtlich vereinbarter Nachhaltigkeitsanfor-
derungen zu beschreiben und zu bewerten. Aufgrund der
erreichbaren Qualitätsstufen kann es ein Anreizsystem für
Bauherren, Planer, Nutzer sowie allen anderen Akteuren
des Bauwesens darstellen. Das Bewertungssystem geht
dabei über die gesetzlichen und normativen Regelungen
deutlich hinaus.
Was bedeutet dies wiederum für den Bereich der Raum-
luftqualitäten?
Mit Beginn der Systementwicklung wurde die klare Ent-
scheidung getroffen, dass die Thematik der Raumluftqua-
lität im Zusammenhang mit Schadstoffemissionen aus
Bauprodukten ein höherer Stellenwert beigemessen wer-
den muss, als es die bisherige Regelungsdichte in Deutsch-
land zulässt. Somit kann beispielsweise kein BNB-Zertifikat
vergeben werden, wenn die Belastung der Raumluft durch
flüchtige organische Verbindungen sowie Formaldehyd
über die empfohlenen Grenzwerte hinausgehen. Zudem
wurde wurden Qualitätsstufen definiert, nach denen das
Gebäude eingestuft wird (Abb.4 und 5).
Für die verbindliche Messung und Bewertung geogenen
Radons in der Raumluft fehlt derzeit noch eine vergleich-
bare Tabelle im Bewertungssystem Nachhaltiges Bauen.
Das Wissen um die Thematik führte unter anderem dazu,
dass in einem ersten Schritt die Qualität der Lüftungsrate
– im Kriterium die zu ermittelnde Personenlüftungsrate –
eine Stellvertreterfunktion übernehmen musste.
Nachhaltige Gebäude mit sehr guten Endbewertungen, ver-
fügen in der Regel über hohe personenbezogene Lüftungs-
raten, die weitestgehend nur durch kontrollierte Lüftung
zu erreichen sind. Gleiches Vorgehen erfolgt im Bereich der
technischen Qualität des Gebäudes bei der Bewertung der
Luftdichtheit der Gebäudehülle – je dichter die Gebäude-
hülle, desto besser die Bewertung der Luftdichtheit.
Somit erfüllt heute das BNB noch nicht direkt, zumindest
aber indirekt wesentliche Anforderungen an radonsicheres
Bauen.
Die Thematik geogenes Radon wird derzeit im BNB-System
für Neubauten im Bereich der Beurteilung des Standortes
u.a. durch das Kriterium BNB_BN_ 6.1.2 Verhältnisse am
Mikrostandort adressiert. Unter Einbeziehung der gebiets-
spezifischen Radonkarte wird die Einstufung des Stand-
ortes informativ dem Bewertungsprozess zugeführt und
stellt somit eine wichtige Basisinformation für die Gebäu-
deplanung dar.
Im Ergänzungsmodul BNB Nutzen und Betreiben wird die
Thematik Radon während der Nutzungsphase im Kriteri-
um BNB_BB 3.1.3 Tatsächliche Innenraumhygiene direkt
betrachtet und bewertet. Für die Bauherren, die regelmä-
ßige Qualitätskontrollen mittels BNB-Modul Nutzen und
Betreiben während der Nutzungsphase vereinbaren, ist die
Radonmessung somit nunmehr obligatorisch.
Abb. 2: Bewertungssystem Nachhaltiges Bauen;
www.bnb-nachhaltigesbauen.de
Abb. 3: Leitfaden
Nachhaltiges Bauen,
BMVBS 2013
Abb. 1: Logo des Bewertungs-systems Nachhaltiges Bauen
Abb. 4: Auszug BNB_BN - 3.1.3 – Teilkriterium Flüchtige organische Stoffe
Abb. 5: Auszug BNB_BN 3.1.3 – Teilkriterium Personenbezogene Lüftungsrate
Zukünftige Entwicklungen
Aufgrund der nationalen und europäischen Entwicklungen
im Hinblick auf Festlungen zu Referenzwerten für geoge-
nes Radon, ist die Integration von verbindlichen Nachwei-
sen zur Radonkonzentrationen im Gebäude für das Bewer-
tungssystem Nachhaltiges Bauen ebenfalls angedacht. Mit
dem geplanten Update des BNB zum Ende des Jahres 2014,
ist die Integration von ersten Qualitätsstufen für Radon im
Steckbrief 3.1.3 Innenraumhygiene erklärtes Ziel. Die Ab-
leitung der Qualitätsstufen erfolgt dabei in enger Abstim-
mung mit dem Bundesamt für Strahlenschutz.
Der Vorteil eines freiwilligen Bewertungssystems liegt u.a.
darin, dass die zu erreichenden Mindestanforderungen
sich einerseits an den nationalen Grenz-/ Referenzwerten
orientieren und andererseits für die BNB-Zielwerte deut-
lich geringere Konzentrationen im Sinne eines nachhalti-
gen Gebäudes vereinbart werden können. In Abhängigkeit
der europäischen Entwicklungen bzgl. der Einstufung/
Beurteilung der Eigenstrahlungen von Baustoffen, besteht
ebenfalls die Möglichkeit diese Thematik mittelfristig in
das BNB-System zu integrieren. Hier werden bei Bedarf die
dafür erforderlichen Abstimmungen mit dem Bundesamt
für Strahlenschutz sowie dem Deutschen Institut für Bau-
technik geführt.
Fazit
Mit dem Bewertungssystem Nachhaltiges Bauen besteht
unabhängig von Richtlinien, Verordnungen und Gesetzen
die Möglichkeit, Gebäude zukünftig in Ihrer Ganzheitlich-
keit besser bewerten zu können. Da es sich um ein offenes
und ständig in der Weiterentwicklung befindliches System
handelt, können Aspekte wie geogenes Radon sukzessiv
stärker als bisher im System Berücksichtigung finden.
Fachvorträge / articles | 45

image
46 | Fachvorträge / articles
1. Einführung
1.1 Problemstellung
Der bauliche Radonschutz hat in Deutschland bisher noch
nicht den Stellenwert erreicht, der sich aus den Erkennt-
nissen zur Gesundheitsgefährdung infolge einer erhöh-
ten Radonkonzentration in Aufenthaltsräumen ergibt. Die
Gründe hierfür sind in erster Linie in fehlenden verbindli-
chen Regelungen und einem geringen Kenntnisstand der
Baufachleute zum baulichen Radonschutz zu finden. Im
Rahmen dieses Beitrages sollen, aufbauend auf einer kur-
zen Darstellung der für Deutschland geltenden Vorausset-
zungen sowie der aktuellen Situation Schlussfolgerungen
für erforderliche Maßnahmen zur Umsetzung der Europäi-
schen Grundnorm in nationales Recht beschrieben werden.
1.2 Bodenradonkonzentration in Deutschland
In Deutschland konzentrieren sich die Gebiete mit hohen
Bodenradonwerten auf einige Mittelgebirgs- und Alpenre-
gionen (siehe Bild 1). Insbesondere sind die Bundesländer
Sachsen und Bayern, im weiteren Thüringen, Baden-Würt-
temberg, Rheinland-Pfalz, Saarland und Nordrhein-West-
falen betroffen.
Schätzungen [1] gehen davon aus, dass in Deutschland
jährlich ca. 1.900 Menschen an durch erhöhte Radonkon-
zentration hervorgerufene Lungenkrebserkrankungen sterben.
1.3 Regelungen im Bauwesen
Der im Bauwesen tätige Architekt, Bauingenieur und Fach-
planer muss im Prozess der Planung sowie Bauausführung
eine Vielzahl unterschiedlicher Regelungen berücksichti-
gen. Die folgende Zusammenstellung lässt die Komplexität
der zu berücksichtigenden Gesetze, Normen und sonstigen
Regelungen erahnen. Auf die Frage, wie bzw. wo sich in
diese Regelungen der bauliche Radonschutz einordnen
lässt, wird im anschließenden Abschnitt 2 eingegangen.
Die gesetzliche Grundlage des Bauens in Deutschland
stellt das Baugesetzbuch dar, in dem u.a. formuliert ist,
Regelungen des baulichen Radonschutzes für
Neubau und Gebäudesanierung in Deutschland
– aktueller Stand und erforderliche Entwicklungen unter
Berücksichtigung der neuen Europäischen Richtlinien
Prof. Dr.-Ing. Walter-Reinhold Uhlig
HTW Dresden, Fakultät Bauingenieurwesen/Architektur
Kompetenzzentrum für radonsicheres Bauen und Sanieren (KORA e.V.)
Prof. Dr.-Ing. Thomas Hartmann
HTWK Leipzig, Fakultät Maschinenbau und Energietechnik
ITG Institut für Technische Gebäudeausrüstung Dresden GmbH
dass gesunde Wohn- und Arbeitsverhältnisse zu be-
rücksichtigen sind.
Die föderale Struktur Deutschlands spiegelt sich im
Baurecht dahingehend wider, dass eine Vielzahl von
grundsätzlichen Fragen in den Bauordnungen der Län-
der gesetzlich geregelt ist.
Sowohl das Baugesetzbuch als auch die Bauordnungen der
Länder können keine konkreten Festlegungen zur planeri-
schen Lösungen sowie deren Umsetzung enthalten. Der-
artige Regelungen sind z.B. in Verordnungen des Bundes,
DIN-Normen, Normen des VDI sowie weiterer Verbände
enthalten. Darüber hinaus existiert eine Reihe, zum Teil auf
freiwilliger Basis begründeten, Regelungen.
In Verordnungen sind besonders wichtige Aspekte des
Bauwesens, wie z.B. Fragen des energetischen Bauens,
geregelt.
In DIN-Normen sowie diese ergänzenden Normen
von Fachverbänden ist eine Vielzahl unterschiedlicher
technischer Lösungen sowie Verfahren beschrieben.
Mit Ausnahme bauaufsichtlich eingeführter DIN-Nor-
men haben sie allerdings lediglich Empfehlungscha-
rakter. Normen bilden zudem nicht automatisch die
allgemein anerkannten Regeln der Bautechnik (aaRdB)
ab. Letztere müssen in der Wissenschaft als theoretisch
richtig erkannt, in der Praxis umfassend bekannt sein
und sich aufgrund langjähriger praktischer Erfahrung
bewährt haben. Für die Feststellung einer mangelfreien
Bauleistung haben die aaRdB überragende Bedeutung.
Um eine hohe Bauqualität zu gewährleisten und ggf.
Gefahrensituationen zu vermeiden, können für einzel-
ne Bauprodukte bzw. Verfahren über freiwillige Ver-
einbarungen, z.B. in der Form eines RAL-Gütezeichens,
ergänzende Kriterien geregelt werden.
Zunehmend werden Europäische Richtlinien als Grundla-
gen für nationale Regelungen beschlossen, wobei den Län-
dern in der Form der Umsetzung ein gewisser Spielraum
zugestanden wird.
2. Aktueller Stand zu Regelungen des
baulichen Radonschutz in Deutschland
Wie in den meisten Ländern Europas existieren in Deutsch-
land keine gesetzlichen Regelungen zum baulichen Radon-
schutz. Lediglich für einige wenige Gruppen von Arbeits-
plätzen sind gesetzliche Grenzwerte zur Begrenzung der
Radonkonzentration am Arbeitsplatz festgelegt worden.
Aus den grundsätzlichen Anforderungen des Baugesetzbu-
ches zur Schaffung gesunder Arbeits- und Lebensbedin-
gungen sowie weiterer gesetzlicher und normeller Rege-
lungen lassen sich, wie Giesbert und Kleve in ihrem Beitrag
auf dem 3. Sächsischen Radontag [2] schlüssig dargestellt
haben, keine zwingenden Regelungen zum baulichen Ra-
donschutz ableiten. Empfehlungswerte zur Begrenzung der
Radonkonzentration in Aufenthaltsräumen sind im Radon-
handbuch Deutschland [3] zusammengefasst.
Bauliche Regeln zur Umsetzung des Radonschutzes, Rege-
lungen aus dem Bereich der Lüftungstechnik, Vorschriften
zur Baustoffprüfung sowie Festlegungen zur Umsetzung
des baulichen Radonschutzes sind für Deutschland nicht
bekannt. Der wichtige Begriff der allgemein anerkannten
Regeln der Bautechnik kann auf bauliche und anlagen-
technische Lösungen des Radonschutzes (noch) nicht oder
nur bedingt angewendet werden.
3. Kenntnisstand zum baulichen
Radonschutz
Im Grunde genommen sind die baulichen und lüftungs-
technischen Möglichkeiten zur Umsetzung des baulichen
Radonschutzes für Neubau und Sanierung bekannt, auch
Bade-Westfalen
wenn diese – wie in Abschnitt 2 ausgeführt - noch nicht
den Stand allgemein anerkannter Regeln erreicht haben.
Für Neubauten liegt der Schwerpunkt auf der Realisierung
einer dichten Gebäudehülle im Bereich der erdangrenzen-
den Bauteile. Besondere Sorgfalt ist dabei auf die luftdich-
te Verwahrung von Rohrdurchführungen sowie den sorg-
fältigen Abschluss von Bauteilanschlüssen untereinander
zu legen, um konvektive Luftströmungen zu verhindern.
Lüftungstechnische Maßnahmen, auf die im Folgenden
im Zusammenhang mit Sanierungsaufgaben eingegangen
wird, können die baulichen Maßnahmen im Neubau ergänzen.
Im Falle der Sanierung bestehender Gebäude ist es oft
nicht möglich, die Gebäudehülle so abzudichten, dass der
konvektive Luftstrom zwischen Erdreich und Gebäudeinne-
rem verhindert wird. Für diese Fälle können die folgenden
Maßnahmen zur Reduzierung der Radonkonzentration in
den Räumen angewendet werden:
Erhöhung der Luftwechselrate in den genutzten Räu-
men: Diese Maßnahme wird vorrangig als Sofortmaß-
nahme angewendet, wenn sehr hohe Radonkonzent-
rationen in der Raumluft festgestellt worden sind. Da
ein erhöhter Luftwechsel gleichzeitig zu höheren Ener-
gieverlusten führt, ist diese Maßnahme für beheizte
Räume allenfalls als temporäre Maßnahme geeignet.
Umkehr des konvektiven Luftstroms zwischen Ge-
bäudeinnerem und dem Erdreich: In der Regel stellt
sich ein Unterdruck im unteren Bereich des Gebäudes
gegenüber dem Luftdruck im angrenzenden Erdreich
ein. Dieser Unterdruck kann durch eine höhere Raum-
lufttemperatur gegenüber der Temperatur im Erdreich
(Winterzustand), durch den sogenannten Kamineffekt
oder aber durch Windanströmung an das Gebäude ent-
stehen. Möglichkeiten, den Unterdruck im Gebäude ab-
zubauen, sind zum Beispiel die Abschottung der Keller-
räume von den darüber liegenden Gebäudebereichen
(Reduzierung des Kamineffekts) sowie die Reduzierung
des Luftdruckes im Erdreich direkt unterhalb der Ge-
bäudesohle. Für letztere Maßnahme werden beispiels-
weise sogenannte Radonbrunnen unterhalb oder direkt
neben dem Gebäude errichtet bzw. wird unter der Bo-
denplatte eine Flächendränage mit direkter Anbindung
an die Außenluft eingebaut. Eine weitere Möglichkeit
ist die Schaffung bzw. lüftungstechnische Aktivierung
von Hohlräumen in bzw. kurz unter der Bodenplatte.
Alle hier genannten Maßnahmen werden so konzipiert,
dass Luft aus dem Boden abgesaugt und somit ein Un-
terdruck im gebäudeangrenzenden Erdreich induziert
wird.
Fachvorträge / articles | 47

In letzter Zeit werden - vor allem im Neubau, aber
auch bei energetischen Gebäudesanierungen - ver-
stärkt Lüftungsanlagen errichtet, die die Regelung der
Luftwechselrate ermöglichen. Beispielsweise durch In-
tegration eines Wärmeübertragers können mit dieser
Lösung die Energieverluste, die sich durch den hygi-
enisch oder bautechnisch motivierten erhöhten Luft-
wechsel ergeben, deutlich reduziert werden. Werden
diese Systeme mit einem geringen Überdruck im Ge-
bäude betrieben (das ist bei Zu-/Abluftanlagen sowie
bei reinen Zuluftanlagen möglich), führen diese Syste-
me im Zusammenhang mit den erhöhten Luftwechsel-
raten zwingend zu einer – zumeist deutlichen – Redu-
zierung der Radonkonzentration in der Raumluft.
Eine fachgerechte Umsetzung der hier kurz skizzierten
baulichen und lüftungstechnischen Maßnahmen kann nur
dann erfolgreich realisiert werden, wenn die Bauschaf-
fenden, aber auch öffentliche und private Bauherren über
genügend Wissen zum baulichen und anlagentechnischen
Radonschutz verfügen. Sowohl im Kreise der Architekten-
schaft als auch der Bauingenieure und weiterer Fachplaner
sind die Lösungen des baulichen Radonschutzes aber bisher
noch zu wenig bekannt. Zudem fehlt sowohl bei den Bau-
herren als auch den Bauschaffenden häufig die Sensibili-
tät hinsichtlich der Erkennung eines Radonproblems. Dies
ist in erster Linie auf fehlende verbindliche Regelungen (s.
Punkt 2) zurück zu führen, aber auch auf die Tatsache, dass
der bauliche Radonschutz bisher in der Ausbildung an Uni-
versitäten und Hochschulen nur eine geringe Rolle spielt
und Weiterbildungsmaßnahmen selten angeboten bzw. nur
von wenigen angenommen werden. Zudem fällt auf, dass
Veröffentlichungen zum baulichen Radonschutz nahezu
ausschließlich aus den Bereichen des Strahlenschutzes
kommen, u.a. durch das BfS, einige Landesämter bzw. Län-
derministerien sowie einige renommierte private Büros, in
erster Linie wiederum aus dem Bereich des Strahlenschut-
zes, der Strahlenschutzmessung sowie der Geologie. Auf-
fällig und durchaus als problematisch einzuschätzen ist die
Tatsache, dass demgegenüber aus dem Bauwesen so gut
wie keine Veröffentlichungen und sonstigen Aktivitäten
bekannt sind. Das betrifft sowohl die Berufsverbände und
Kammern, Verwaltungseinheiten, die Bauforschung sowie
Planer und die Baustoffindustrie. Diese Beobachtung ist
deshalb als problematisch einzuschätzen, da dadurch die
spezifischen Fragen und Antworten, die sich im Zusam-
menhang mit der Planung und Bauausführung ergeben (s.
u.a. Hinweise zu rechtlichen Regelungen des Bauwesens in
Punkt 1.3.) zu wenig Berücksichtigung finden.
4. Aktivitäten in Deutschland
4.1 Ein Überblick über die zu lösenden Fragen
Die Ausführungen der Abschnitte 2 und 3 zeigen, dass im
Vorfeld der Umsetzung der Europäischen Grundnorm in
nationales deutsches Recht eine Reihe von Fragen geklärt
und umgesetzt werden müssen. Das betrifft vor allen Din-
gen die folgenden Schwerpunkte:
Schaffung klarer Prüfregeln für Baustoffe und Bau-
konstruktionen;
Formulierung von Regeln zur Messung der Radon-
konzentration in der Raumluft vor sowie nach einer
Baumaßnahme einschließlich der Einführung von Re-
ferenzwerten;
Beschreibung geeigneter baulicher und anlagentech-
nischer Radonschutzmaßnahmen einschließlich der
Formulierung von Qualitätsstandards in der Bauaus-
führung;
Umfassende Schulung und Weiterbildung der Bauaus-
führenden sowie Sensibilisierung der öffentlichen und
privaten Bauherren für Fragen des Radonschutzes.
4.2 Institutionelle Aktivitäten
Traditionell werden Fragen des Radonschutzes im Bundes-
amt für Strahlenschutz (BfS) behandelt. Dabei muss einge-
schätzt werden, dass bisher die in Punkt 4.1 aufgeworfe-
nen Fragen deutlich zu kurz gekommen sind. Die aktuelle
Situation in Deutschland ist für das Bauwesen insofern
unbefriedigend, dass in nahezu alle Richtungen Rechtssi-
cherheit fehlt. Die Lösung kann nur darin gefunden wer-
den, dass eine intensive Zusammenarbeit mit der Baubran-
che mit dem Ziel gefunden wird, dieser klare Regelungen
an die Hand zu geben. Es ist dabei unerheblich, ob diese in
Form von Gesetzen, DIN- oder anderen Normen oder aber
durch die Formulierung von Qualitätsstandards, z.B. über
ein RAL-Gütesiegel erarbeitet und eingeführt werden.
Entsprechende Regelungen sind dabei für die folgenden
Themengruppen erforderlich:
Definition von Zielwerten: Hier dürften die Referenz-
werte der EU-Grundnorm entsprechende Klarheit brin-
gen, auch wenn für das Bauwesen die Anwendung von
Referenzwerten bisher nicht üblich ist und deshalb zu
Unsicherheiten bei der rechtlichen Bewertung führen
wird. Da es aber weitestgehend Konsens ist, dass die
Definition von Grenzwerten aus fachlicher Sicht prob-
lematisch ist, sollte das Bauwesen mit dieser Situation
umzugehen lernen.
Festlegung von Regularien zur Radonmessung und
Qualitätskontrolle: Es müssen eindeutige Regelungen
erarbeitet und eingeführt werden, wann und in wel-
cher Form sowie mit welchen Verfahren die Radon-
konzentration gemessen wird. Ebenso sind einheit-
liche und reproduzierbare Regelungen zur Messung
der Radonexhalation aus Baustoffen festzulegen. Bei
allen Festlegungen muss dabei der Schwerpunkt auf
der Reproduzierbarkeit von Messungen und damit der
Möglichkeit einer unabhängigen Kontrolle sowie der
Definition klarer Qualitätsstandards liegen.
Beschreibung von Bau- und Technikstandards für den
baulichen Radonschutz im Neubau und bei der Sa-
nierung: Wie bereits in Abschnitt 3 festgestellt, sind
bauliche und lüftungstechnische Lösungen für Neu-
bau und Sanierung weitestgehend bekannt. Fragt man
allerdings Bauingenieure und Architekten nach ihrem
diesbezüglichen Wissen, muss festgestellt werden,
dass die Möglichkeiten bisher viel zu wenig bis zu den
baupraktisch Tätigen durchgedrungen sind. Eine ähnli-
che Situation kann auch für die Lüftungsbranche kon-
statiert werden. Sowohl für den Bauschaffenden als
auch den Bauherren dürfte die Tatsache, dass vor allen
Dingen im Sanierungsbereich die übliche Wirkungskette:
Realisierung einer baulichen und anlagentechnischen Lö-
sung mit einer definierten Ausführungsqualität führt plan-
bar zu einem bestimmten Ergebnis
für den Radonschutz nicht zwingend anwendbar ist. Dies
wird mit Sicherheit zu rechtlichen Fragen und ggf. Irritati-
onen führen, die dringend einer Klärung bedürfen.
4.3 Aus- und Weiterbildung
Die Vermittlung ausreichender Kenntnisse zum baulichen
Radonschutz ist für alle im Bauwesen Tätigen eine zen-
trale Aufgabe der nächsten Jahre. Hier sind neben den
Universitäten und Hochschulen vor allen Dingen Weiter-
bildungsträger, die Kammern, aber auch staatliche Stellen
angesprochen. Die bisherigen Aktivitäten in Deutschland
konzentrieren sich im Wesentlichen auf Initiativen aus
Bayern und Sachsen mit der
Ausbildung zur Radonfachperson (nach Schweizer Vor-
bild), der
Durchführung des Sächsischen Radontages durch das
Kompetenzzentrum für radonsicheres Bauen und Sa-
nieren (KORA e.V.) gemeinsam mit dem Sächsischen
Ministerium für Umwelt und Landwirtschaft (SMUL),
der gemeinsam mit seiner Vorgängertagung in diesem
Jahr bereits zum 9. Mal stattfand sowie
einigen wenigen Initiativen von Weiterbildungsträgern
und Fachpersonen in ganz Deutschland.
Allerdings kann erfreulicher Weise beobachtet werden,
dass es in den letzten Jahren ein steigendes Interesse an
Weiterbildungsmaßnahmen im Bereich des baulichen Ra-
donschutzes gibt.
Die Integration des baulichen Radonschutzes in das Ar-
chitektur- und Bauingenieurstudium ist bisher lediglich
an der HTW Dresden gelungen, wo seit 2009 eine eigen-
ständige Lehrveranstaltung angeboten wird. Auch hier gibt
es inzwischen erste Aktivitäten, diese Initiative auf weitere
Universitäten und Fachhochschulen zu übertragen.
5. Zusammenfassung
Das Wissen zum baulichen Radonschutz ist vorhanden und
vielfältig erprobt. Trotzdem kann es aktuell nicht als „all-
gemein anerkannte Regeln der (Bau-)technik“ eingeordnet
werden, da nicht davon auszugehen ist, dass die Fragen
und Lösungen des baulichen Radonschutzes allgemein be-
kannt sind und es bisher keine klaren Regularien für deren
Umsetzung gibt. Der Beschluss der EU-Grundnorm und
dessen Überführung in nationales Recht erfordert deshalb
in den nächsten Jahren vielfältige Aktivitäten. Dabei sind
vor allen Dingen die im Bauwesen tätigen Hochschulen
und Forschungseinrichtungen, Weiterbildungsträger und
öffentlichen Einrichtungen, aber auch die Gesetzgebung in
Bund und Ländern gefragt, das Wissen zum Radonschutz
in die Baupraxis zu überführen und gleichzeitig ein Regel-
werk zum baulichen Radonschutz zu schaffen.
Literaturverzeichnis:
[1] Gesundheitliche Auswirkungen von Radon in Wohnungen
(www.bfs.de/de/wirkungen/wirkungen_radioaktive_stoffe/radon_
ges.html)
[2] Gisbert, Ludger und Guido Kleve: Öffentlich-rechtliche Ver-
antwortung und zivilrechtliche Haftung für Radonbelastung; Ta-
gungsband 3. Sächsischer Radontag, Dresden 2009
[3] Bundesministerium für Umwelt, Naturschutz und Reaktorsi-
cherheit: Radon-Handbuch Deutschland, Bonn 2001
48 | Fachvorträge / articles
Fachvorträge / articles | 49

50 | Fachvorträge / articles
Abstract
This paper aims to summarize the current situation in
Spain in terms of regulations and procedures related to
protective measures targeting radon gas by providing a
general overview on the normative and regulatory lands-
cape and describing the guidelines of the draft legislation
for protection against radon gas in Spain´s national buil-
ding regulations.
The Consejo de Seguridad Nuclear (Council for Nuclear
Safety, or CSN), has been addressing radon issues since
1989, and recently has delivered a map which identifies
the specific national geographies that are demonstrated
to be prone to radon risk, specific regulations for work-
places and a documented methodology to deal with radon
protection.
The Ministerio de Vivienda (Ministry of Housing), appro-
ved in 2006 a performance-based national building regu-
lation which specifies the fundamental requirements or
performance that buildings must provide for compliance.
This regulation, known as Código Técnico de la Edificación
(Building Code, CTE), addresses hygiene and health, inclu-
ding indoor air quality, and specifies the conditions indoor
air must have in relation to general pollutants. It does not,
however, include any explicit guidelines relating to the im-
pact of radon on air quality.
The Ministerio de Fomento (Ministry of Public Works), in
collaboration with the CSN and relying on technical sup-
port from the Instituto de Ciencias de la Construcción
Eduardo Torroja (Eduardo Torroja Institute for Construc-
tion Sciences, IETcc), from the Consejo Superior de Investi-
gaciones Científicas, (High Council for Scientific Research,
CSIC), is currently developing a draft extension to the CTE,
revisiting the requirement for indoor air quality to take
into consideration protection against radon in residential
buildings.
1. Current state of radon risk awareness
and protection in Spain
Protecting people against radon in buildings is a burgeo-
ning issue. To date, the main issues addressed by building
performance analyses were more “traditional”, dealing
with energy saving, noise insulation, damp protection, fire
safety, and so on. Because of improved awareness provi-
ded by European directives and international and national
entities (such as WHO and the Spanish Ministry of Health
and Social Policy), national authorities have more recently
begun to develop guides, recommendations and instruc-
tions on the matter.
1.1. Nuclear Safety Council (CSN), maps, instructions and
guidance documents
The Nuclear Safety Council (CSN) is the Spanish authority
in charge of nuclear safety and radiology protection: na-
tural and artificial.
Although there is no specific state policy on radon pro-
tection the CSN, in collaboration with other entities and
universities, has dedicated the last 25 years to the bet-
ter understanding of existing radon levels with the aim
of improving the use of public resources in the design of
protection strategies.
As a partial transposition of 96/29 EURATOM Directive [1],
CSN approved the Royal Decree 783/2001 “Regulation on
sanitary protection against ionizing radiation” [2]. Another
part of the Directive had been transposed in the Royal
The future Spanish Building Code on the
radon protection area and the current
regulatory situation in Spain
Linares-Alemparte, Pilar - Architect
Eduardo Torroja Institute for Construction Sciences. CSIC
García-Ortega, Sonia - Industrial Organization
Engineer
Eduardo Torroja Institute for Construction Sciences. CSIC
Decree 1836/1999 “Regulation on nuclear and radioactive
facilities” [3]. The Royal Decree 783/2001 describes which
commercial & industrial activities must control their ra-
don levels, but without specifying which control measures
must be taken.
To further develop this work, CSN published (2012), the
compulsory “Instruction IS-33 on radiological criteria for
the protection against the exposition to natural radiation”
[4] which establishes the protective measures (technical
and administrative), required to be taken in workplaces,
based on an annual mean radon concentration during
working hours:
< 600 Bq/m
3
, no control is necessary
600 &
1000 Bq/m
3
, low control is necessary
> 1000 Bq/m
3
, high control is necessary
In schools and workplaces where people spend long
periods of time, including prisons and hospitals; the
reference level is lower: 300 Bq/m
3
.
Furthermore, CSN has developed a number of methodolo-
gy-based guidance documents, among which we highlight
“GS-11.01 Guideline on laboratories competences and ser-
vices of radon measurement in air” [5], “GS-11.02 Control
of natural radiation exposition” [6] and “GS-11.04 Method
for the assessment of radon exposition in work places” [7].
In addition to the above mentioned instructions and gui-
delines, CSN has developed a map of radon-prone areas
in Spain which shows the potential radon exposition rate
of peninsular land at a 1:1.000.000 scale [8]. The map has
been produced combining data from indoor radon measu-
rements with natural č-radiation (microroentgens per hour
at 1 m above ground, MARNA map) [9] [10], and geologi-
cal maps. This approach relaxes the need for high density
sampling by using commonly available information. It can
be applied for an initial definition of radon-prone areas.
The map classifies an area as radon-prone when the 90th
percentile of predicted indoor radon concentration in its
building stock is greater than the reference level: 300 Bq/m
3
.
As can be seen from the map, the radon-prone area ext-
ends in areas of the North – West and the centre of Spain.
Taking into account the Spanish Population and Housing
Census from the Instituto Nacional de Estadística (Natio-
nal Institute of Statistics) [11], map of radon-prone areas
[8], MARNA map [9] and other measurement campaigns
[12], the number of adversely affected households is esti-
mated at around 1.6 million households from a total of
25.2 million.
The indoor radon database used to do the radon-prone
areas map currently has over 11000 records. The sampling
density is spatially heterogeneous, tending to be higher in
areas with high radon level and more populated. This da-
tabase has got some limitations: it neither details precise
location, nor provides information on building construc-
tion details. Furthermore, the number of measurements is
reduced compared to the building stock.
A new sampling campaign was launched in 2013 with a
predicted three-year lifespan, in order to provide base
data to improve the current radon-prone map covering
the whole territory of Spain, including the Balearic and the
Canary islands.
Fachvorträge / articles | 51

52 | Fachvorträge / articles
1.2. Ministry of Public Works and Building Code
In 2006 the Ministry of Housing approved the current na-
tional Building Code (CTE) [13] - a performance-based re-
gulation which specifies the fundamental requirements or
performance which buildings must fulfil.
The CTE comprises: Energy saving, Noise insulation, Struc-
tural safety, Use safety and Accessibility, Safety in case of
an event of fire, and Hygiene and health. This final require-
ment deals with matters such as protection against damp
& condensation, waste management, water supply & drai-
nage, and indoor air quality. The requirement for indoor
air quality specifies the conditions required in relation to
general pollutants, but it does not include an explicit re-
quirement on radon.
Therefore, and because of the rising awareness of society
and various recommendations of international and natio-
nal entities, the Spanish Ministry of Public Works, with the
collaboration of CSN and the technical support of the Edu-
ardo Torroja Institute for Construction Sciences from the
CSIC, is developing a draft on radon protection regulation
to be included in a forthcoming revision to the CTE.
2. Radon protection regulations within
the Building Code
The main goal of this regulation is to protect the popula-
tion from the negative effects on health produced by the
accumulation of indoor radon gas.
The scope of this regulation would specifically be housing,
due to the long exposure times and because workplaces
are already regulated in Instruction IS-33.
It is well known that indoor radon concentration depends
directly, among other factors, on building characteristics.
Therefore this regulation intends to enforce the implemen-
tation of appropriate building solutions, depending on the
actual indoor radon concentration in existing buildings, or
on the expected concentration in new buildings.
A concentration limit will be set up that will be used to
calibrate the remedial or protective measures to take.
The proposed methodology is different for existing and
new buildings. For existing buildings the process starts
with the measurement of the indoor radon concentration
prior to any works and then, according to this level, a set
of remedial solutions will be advised until the measured
concentration is below the limit. For new buildings the
process starts with the estimation of the radon high con-
centration risk and then, according to the risk level, a set
of protective solutions will be recommended.
2.1. Estimation of the radon high concentration risk in new
buildings
Between the two most commonly used methods in inter-
national radon regulations for establishing the high con-
centration indoor radon risk, the use of on-site measure-
ments of relevant soil characteristics is proposed instead
of the use of the available radon-prone areas map.
The map of radon-prone areas we mention above can be
used for guiding territorial policies on radon protection
and for getting to know the degree of the problem in each
geographical area - though recall that data is sparse in
some areas.
Therefore the on-site measurements alternative has been
chosen as a better way to determine the risk. Following the
Czech Republic method described in čSN 73 0601 [14], the
risk is established as a function of the soil radon concent-
ration and the soil air permeability.
2.2 Remedial and protective solutions
Having estimated the risk or measured the indoor radon
concentration, there will be a graduated scale of applicable
solutions to address each grade of pollution. The solutions
included in the draft are already well-documented in the
literature [14] [15] [16], and reportedly effective. For new
buildings, the currently proposed graduated scale inclu-
des for medium risk the use of radon-proofed barriers and
for high risk the use of, in addition to the barrier, other
systems based on sub-floor depressurization (sumps) or
ventilation.
Acknowledgments
Marta García-Talavera. CSN.
References
[1] Council Directive 96/29 EURATOM Laying down basic stan-
dards for the health protection of the general public and workers
against the dangers of ionizing radiation. OJ L159.
[2] Real Decreto 783/2001, de 6 de Julio, Reglamento de protec-
ción sanitaria contra las radiaciones ionizantes, BOE 178, de 26 de
Julio de 2001.
[3] Real Decreto 1836/1999, de 3 de diciembre, Reglamento sobre
instalaciones nucleares y radiactivas, BOE 313, de 31 de diciembre
de 1999.
[4] CSN Instrucción IS-33 sobre criterios radiológicos para la
protección frente a la exposición a la radiación natural. BOE nº 22
de 26 de enero de 2012.
[5] CSN 2011 Guía de Seguridad 11.01 Directrices sobre la com-
petencia de los laboratorios y servicios de mediad de radón en el
aire (Madrid:CSN).
[6] CSN 2011 Guía de Seguridad 11.02 Control de la exposición a
fuentes naturales de radiación (Madrid:CSN).
[7] CSN 2011 Guía de Seguridad 11.04 Metodología para la
evaluación de la exposición al radón en los lugares de trabajo
(Madrid:CSN).
[8] García-Talavera, Marta et al. Mapping radon-prone areas
using č-radiation dose rate and geological information. Journal of
radiological protection, 33 (3) (2013): 605-20.
[9] Proyecto MARNA. Mapa de radiación gamma natural. Consejo
de Seguridad Nuclear. Colección Informes Técnicos 5.2000. ISBN:
84-95341-12-3.
[10] Quindós Poncela, L.S. Natural gamma radiation map (MARNA)
and indoor radon levels in Spain. Environment International, 29
(2004): 1091–1096.
[11] Censos de Población y viviendas 2011. Instituto Nacional de
Estadística.
http://www.ine.es/en/censos2011_datos/cen11_da-
tos_res_pob_en.htm
[12] CSN Concentraciones de radón en viviendas españolas. Ot-
ros estudios de radiación natural. Colección Informes Técnicos
13.2004. Referencia INT-04.09.
[13] Real Decreto 314/2006, de 17 de marzo, Código Técnico de
la Edificación. Ministerio de Vivienda, BOE 314, de 28 de marzo
de 2006.
http://www.codigotecnico.org/ingles/introduction/
[14] Ochrana staveb proti radonu z podloží. čESKÁ TECHNICKÁ
NORMA. čSN 73 0601
[15] Chris Scivyer. Radon. Guidance on protective measures for
new buildings. BRE Press. 2007. Watford. UK
[16] Bernard Collignan. Guide technique: Le radon dans les bati-
ments. CSTB. 2008
Fachvorträge / articles | 53

Background
The National Radon Survey was carried out by the Radiolo-
gical Protection Institute of Ireland (RPII) during the 1990s.
This survey, which was based on measurements in over
11,000 homes, predicted that 7% of the national housing
stock in existence at the time had radon concentrations
above the National Reference Level of 200 Becquerels per
cubic metre (Bq/m
3
) for radon in homes
1
. Based on the
results of the survey, a map of Radon in Irish Dwellings
was published (Figure 1)
2
, identifying High Radon Areas
3
.
Approximately one third of the country, mainly in the west
and south-east, is classified as a High Radon Area. Due pri-
marily to geological factors the radon problem in Ireland
is greater than for many of our European neighbours. The
average indoor radon concentration in Ireland is 89 Bq/
m
3
, which is the eighth highest among 29 OECD countries
surveyed by the World Health Organisation
4
. Some of the
highest indoor radon concentrations, found anywhere in
Europe, are in Ireland.
It is the greatest source of exposure to ionising radiation
for the general public and the second greatest cause of
lung cancer in Ireland. It is estimated that exposure to ra-
don accounts for approximately 13% of all lung cancers in
Ireland, which equates to some 250 lung cancers each year.
The Reference Level for the long-term exposure to radon
in homes is 200 Bq/m
3
measured in accordance with the
RPII’s measurement protocol. This Reference Level, which
was set by Government in 1990, is in line with the recom-
mendations of the World Health Organisation
5
.
Building Regulations:
The Building regulations introduced requirements in 1997
which stated “Reasonable precautions shall be taken to
avoid danger to health and safety caused by substances
(including contaminants) found on or in the ground to be
covered by a building” and defined “contaminant” as “any
substance which is or could become flammable, explosive,
corrosive, toxic or radioactive and any deposits of faecal
or animal matter;”
The Technical Guidance Document to the regulations spe-
cified two requirements for dwellings and other long-stay
residential buildings depending on the designation of the
location:
1
. High Radon Areas
- a fully sealed membrane of low
permeability over the entire footprint of the building and
a potential means of extracting Radon from the substruc-
ture such as a standby Radon sump or sumps with con-
necting pipe work or other appropriate certified systems
2. Areas other than High Radon Areas
- the provision
of a standby Radon sump or sumps with connecting pipe
work or other appropriate certified systems.
The pipe work from standby Radon sumps, should termi-
nate and be capped either above ground level externally, or
in the attic space. Pipe terminals should be clearly marked
to indicate the function of the pipe work system to facili-
tate later activation should this prove necessary and also
prevent misuse.
Schools
The statutory Reference Level for radon in workplaces of
400 Bq/m
3
also applies to schools. However, in order to
provide the same level of protection as in the home, the
RPII recommends a Reference Level of 200 Bq/m
3
in all
schools. This advice covers pre-schools as well as primary
and post-primary schools.
Between September 1998 and June 2004 the RPII, on be-
half of the Dept. of Education and science (DES), carried
out a national program of radon measurements in primary
and post primary schools in Ireland. All rooms with a radon
concentration over the reference level of 200 Bq/m
3
were
to be identifying and remediated.
38,531 ground floor classrooms and offices in 3,826
schools were measured and 3,028 rooms were found to be
over the reference level. Of these 800 were over 400 Bq/
m
3
and 126 had a measurement over 1000 Bq/m
3
. Large
variations were observed between adjacent rooms in some
cases.
Priority was given to schools with radon measurements
over 400 Bq/m
3
and a consultant was employed by DES
54 | Fachvorträge / articles
Radon in Ireland and the
New National Radon Strategy
Eamonn Smyth - (DECLG, Ireland)
to design active sump remediation systems for 93 schools
between 2000-2002. After a study of ventilation rates in
schools found that existing rates were poor, it was decided
to remediate schools with radon measurements between
200-400 Bq/m
3
by increasing the background ventilation
giving the added benefit of good indoor air quality.
Post remediation tests showed excellent results where ac-
tive sumps were used with 95% of the remediated rooms
below the 200 Bq/m
3
reference level and only 1% above
the 400 workplace reference level. Reductions were also
observed in adjoining rooms not remediated. A 55% re-
duction in levels was observed in rooms remediated by
background ventilation which was sufficient for the range
of measurements treated ie 200- 400 Bq/m
3
.
National Radon Control Strategy
Radon is the greatest source of radiation exposure to the
public. Experience in Ireland and abroad has shown that an
effective response to the radon problem involves a wide
range of interventions including:
effective prevention in new buildings,
identification of existing homes and workplaces with
high radon levels,
remediation of existing buildings,
awareness raising,
training, supports and enforcement.
It is clear that such a response requires action from a wide
range of public bodies and other stakeholders and can
be best achieved within the framework of a coordinated
Government-led strategy.
The aim of the National Radon Control Strategy is to mi-
nimise the exposure to radon gas for people in Ireland
and to reduce to the greatest extent practicable the in-
cidence of radon related lung cancers. Thus, the Strategy
1
The Reference Level is not a rigid boundary between safety and danger but represents a radon concentration above which action to
reduce radon levels is likely to be needed.
2
An interactive radon map is published on the RPII’s website:
www.rpii.ie.
3
A High Radon Area is one where it is predicted that more than 10% of homes will have radon concentrations above 200 Bq/m
3
4
World Health Organisation, 2009, Handbook on Indoor Radon – A Public Health Perspective. This handbook is a key product of the
WHO International radon project which was part funded by the Irish Government.
5
World Health Organisation, 2009, Handbook on indoor radon – A public health perspective. The is available at:
http://www.who.int/ionizing_radiation/env/radon/en/index1.html.
The handbook is a key product of the WHO International radon
project which was part funded by the Irish Government.
recommends a broad range of measures, 48 in total, based
around six thematic areas as follows:
Radon prevention in new buildings;
Use of property transactions (sales and rental) to drive
action on radon;
Raising radon awareness and encouraging individual
action on radon;
Advice and guidance for individual householders and
employers with high radon results;
Promoting confidence in radon services; and
Addressing radon in workplaces and public buildings.
From the construction industry standpoint the main re-
commendations are:
1
Short targeted training courses should be provided for
site staff on the correct installation of radon preventive
measures and on maintaining the integrity of those mea-
sures once installed. The aim of this would be to:
Explain the dangers of Radon
The purpose of the standby sump
The necessity of maintaining the barrier intact
This course to be done through industry groups.
2
Basic information on radon should be included on un-
dergraduate courses related to the construction industry.
Currently the 3rd level training appears to deal with
barriers as part of the Damp Proof Membranes (DPM)
for buildings without any emphasises on the dangers
or reasoning behind the requirements.
National reference levels etc
Fachvorträge / articles | 55

image
56 | Fachvorträge / articles
3
In cooperation with the relevant professional bodies
education on radon should be integrated into the existing
system of continuous professional development (CPD) for
building professionals.
The aim here would be to increase the expertise of the
construction professional both for prevention and re-
sultant remediation
Explain other remediation methods
Design methods to reduce the risk of damage to barriers
4
A web based knowledge resource on radon should be
developed for the building industry. The aim is to have
available:
Information on the dangers,
methods of prevention and remediation,
FAQ’s (Frequently asked questions) for the homeowner
and the professional.
5
The relevant Technical Guidance should be amended to
require that a passive sump be installed in all new dwellings
There is increased evidence that a passive sump redu-
ces radon by 50% or more
Little added cost to the current sump requirements
Aids the proper positioning and installation.
6
The relevant Technical Guidance should be amended to
include provisions, which would allow radon preventive
measures to be more easily identified on site.
7
The current requirement that barriers are required in
High Radon Areas should stand. Research should be car-
ried out to assess the combined effectiveness of passive
sumps and barriers compared to the effectiveness of bar-
riers alone.
8
Research on better barrier systems and the appropria-
te placing of barriers to improve barrier success rate and
decrease post-installation damage should be undertaken.
9
Other Research themes for better prevention and reme-
diation incl.:
Research on passive sumps and barrier vs passive sump
only
Improved barrier installation
More evidence on effectiveness of prevention and re-
mediation
Insulation retrofit and radon levels
Awareness programs are also being developed to increa-
se the testing and remediation of existing buildings. This
combined with the development of a recognised list of
competent remediation companies to give confidence to
the home owner should lead to greater numbers of dwel-
lings being rectified.
It is hoped that all the actions combined will have a signi-
ficant impact on current Radon levels and reduce the risk
to people in Ireland.
Figure 1

58 | Fachvorträge / articles
Fachvorträge / articles | 59
Corroventa assets
Corroventa business unit: Living Environment:
Radon mitigation
Equipment developed for the purpose, rental of instru-
ments for radon measuring
Many years of actual experience in measurement and
investigation, est.19 000, and radon mitigation projects
est. 3 000.
National Targets Radon- Target- and limit values in Sweden.
Homes: 200 Bq/m
3
, Schools: 200 Bq/m
3
Workplaces: 200 Bq/m
3
(Acc. To AFS 2011:18. Valid
from 1th of july 2012)
National radon target (Parliament‘s objective indoor
Climate proposition)
Radon level in all schools and preschools shall be
below 200 Bq/m
3
at year 2010.
Radon level in all homes shall be under 200 Bq/m
3
at
year 2020.
Also: All buildings where people frequently or for lon-
ger period reside at latest the year of 2015 has a docu-
mented efficient ventilation.
Radon work in Sweden, Allocation of responsibility, many
different parties involved in different areas due to indoor
radon.
Situation in Sweden
The situation for dwellings in Sweden, average value in
Sweden, radon concentration and number of dwellings
over a value of 200 Bq/m
3
estimated to 500 000 pcs or
12% and over a value of 400 Bq/m
3
estimated to about
150 000 pcs or 3,7%.
Sources of indoor radon concentrations
1. Soil gas: In Sweden we have bedrock that in principle
for 90% of our suitable area for development has so much
radon gas in the ground that, under certain conditions can
cause measurable radon gas values in our buildings.
2. Building materials: Building materials that produce ra-
don gas itself to such an extent that it gives a not negligi-
ble contribution of radon gas to our homes and buildings.
The most high-producing material is commonly known as
“blue autoclaved lightweight concrete” primarly used in
Sweden during 1920-1975. But the fact is that basically all
domestic stone materials contribute to measurable level of
radon in our homes.
3. Water: We also have radon transported through our tap
water into the housing and which produces radon gas pre-
sence.
What is special for Sweden is the autoclaved lightweight
concrete which we always has to consider when doing ra-
don investigations.
Production of autoclaved lightweight concrete i Sweden
Produced 63000000 (m
3
) during the time period of 1929-
1975 with a gammaradiation of 0,25-1,00 μSv/h.
Estimated presence in existing dwellings in Sweden.
30 000 houses of apartment buildings and 125 000 family
houses.
Season for measurement
The time for measurement of radon level should in Sweden
be made during the period of heating season 1/10 – 30/4.
Assumed period when average daily temperature is below
+10˚C. Most important is that the difference between in-
door and outdoor temperature is sufficient for natural
ventilation to operate.
Placing the radon meter in apartment buildings
In apartment buildings measuring should be done in all
apartments in the bottom floor.
When it´s not above a cellar floor.
In floors above at least one apartment per floor, and
cover at least 20% of the apartments i higher floors.
All apartments in connection with elevator- or ventila-
tionshafts should be measured.
Choose methods of radon mitigation - Some basic themes
that we try to follow when we work with radon mitigation
/ planning.
If it’s building materials that produce radon:
Dilution of the production ”as far as this is possible”.
Venting of the surface layer.
Removal of material producing radon gas
Radon mitigation in dwellings
using radon exctractors
Mattias Park
Corroventa Avfuktning AB, Sweden
If it´s soil gas:
Changing the pressure conditions in the housing body.
Dilution of the incoming air leakage.
Sealing of structures.
If it’s from water:
Venting the water before leading into the house.
The choice of technologies and systems should always
be made so that existing installations can continue to
serve the house in a valuable manner.
Always to consider when selecting systems and technology
The technique should also have a long-term functio-
nal and adjusted to the unique house, where changes
that could negatively affect the building structures are
avoided.
It should under no circumstances occur comfort prob-
lems due to the selected technology / systems.
Energy use should be considered when choosing an
systems and technology. „Use the amount of energy is
reasonably proportionate to the completed case. “
Systems and technology should be easy to service and
repair so that maintenance and repairs can be made
quickly and easily.
Typical radon mitigation family house, example
This is a typical object where an installation of a radon
extractor fan in the basement most often is the cheapest
and most efficient solution. What causes the contami-
nated air to enter the house is the lower pressure in the
house caused by the ventilation, mechanical or caused by
the chimney/stack effect. Therefore the key is to modify
the pressure ratio between the living environment and the
pressure under the house. A common mistake is to increase
the ventilation in the house. That results in an even lower
pressure inside the house which causes even more conta-
minated air to be sucked into the house from the soil and
thus increasing the radon level instead of decreasing it.
For the installation with a radon extractor fan RS400 was
chosen since the soil under the house is relatively porous
and air flow rather than pressure is needed to build up the
required under pressure. The tubing system in the house
could also be built quite compact and thus the pressure
performance of the RS100 is not needed.
The process lowers the pressure under the house to a level
below the pressure inside the house. That eliminates radon
contaminated air from entering the living environment
completely or decreases the amount significantly. Where
possible, leakage between the soil and the house is also
sealed, i.e. at lead through for drainage pipes etc.
Longtime measurement in apartment building
The importance to present the measuring data to the cus-
tomer in a understandable and easy way.
Mitigation of radon with by new ventilation system, S –
FTX, Present result of measuring before and after the in-
stallation. High levels caused of building material. Which
can be very difficult to measure. Therefore measuring of
gamma radiation has to be done. So you get proper vau-
les for the contribution of the Bequerel concentration and
then can calculate the air circulation needed to achieve
desired radon levels.
Some things to remember about Ventilation FTX and pre-
sentation of the result after a mitigation with exhaust ven-
tilation system (F) and supply air vents.
Actionplan – how to plan the steps in a radon mitigation
project.
To deal with concerned tenants and our experiences. The
importance of handing every tenant in a good way is a
factor to consider achieving a good result.
Project with a combination changing the ventilation and
radon extractors.
The action plan radon mitigation. The importance of telling
the customer the plan and timeschedule. Example of ins-
tallation of radon extractors in cellar and presentation of
the measured results after installation.
Some examples of how the installation can be done with
pictures.
General goals when installing is to aim for low noise ,easy
to access for service but not too easy access for tenants.
Good mounting equipment to use is wall brackets, moun-
ting plate, straps and silencer for the exhaust pipe.
Drilling in the ground slab and sealing:
The dimension of the drilled hole has to be big enough
to give access to dig out material from under the slab. At
least a “big bucket” of material. It is important to make
some volume in the gravel under the slab on ground at
each suction point in order for the fan to work properly.
That is to ensure that the hole doesn’t collapse and risk
that material will be sucked into the pipes and do damage
to the equipment.
Drilled hole dimension is often between 80-110 mm. A
diminishing hose is used to fit to the piping system. The
drilled holes can be sealed with various methods.
The longtime measuring presentation with the results be-
fore and after the mitigation project. To use as a receipt for
the customer that he has got the result he paid for. And a
good documentation has to be done also for proving that
the dwelling is “radon secured”.

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