R a d o n S a f e

Norway, Sweden and Finland are among the countries with highest concentrations of indoor radon in the world.It has therefore become a major focus in the construction industry on strategies both for radon prevention in new buildings and mitigation in existing. The authorities require that risk of radon gas penetration into buildings is eliminated.

A recommended solution is sealing building by use of airtight radon membrane under the construction with sufficient resistance to radon gas penetration.

Protan AS has developed Protan RadonSafe, a membrane which offers an optimal protection against penetration of radon gas into new buildings

The Protan RadonSafe membrane ensures an airtight seal that prevent radon gas penetrating into the building when installed by professionals, trained by Protan.

Protan RadonSafe.Radon is an invisible, odourless gas which will typically seep through constructions where penetration is easiest. It is therefore vital to ensure that corner details, pipe penetrations and other penetrations are 100% airtight. Protan RadonSafe is a reinforced TPO membrane for protection of buildings from exposure to radon penetration from the ground. Application areas for the membrane are application classes B or C.

Protan RadonSafe may be installed both in application classes B and C. Overlaps are joined by hot-air welded seams.This ensures high density of seams to prevent radon penetration.

Facts

• Radonisanoblegasproducedbytheradioactivedecayofuraniumandthorium,whichareelementsnaturallypresentintheearth’scrust. It is invisible and odourless, and non-detectable by any of the human senses. This noble gas is prevalent in varying concentrations in certain types of rock. Due to its specific geological conditions, climate and local traditions of construction the Nordic countries have the highest indoor concentrations of radon in the world.

• RadongasesareproducedbynaturalradioactivityLarge differences between indoor and outdoor temperatures, especially during winter, tend to increase the concentration of radon gas inside buildings. Radon concentration in dwellings should never exceed 200 Bq/m3 (Becquerel). The costs of various measures vary, but it will always be cheaper and easier with preventive measures during construction, such as installation of radon membranes.

• PlanningandBuildingActof1997,uptodatewithchangesin2007§8-33Section4Radon “Construction of buildings shall in terms of building design ensure that people who reside in a building are not exposed to radon concentrations in indoor air, which may cause increased risk to human health.» NRPA (Norwegian Radiation Protection Authority) recommends measures are taken when radon concentration exceeds 100 Bq/m³. A European regulation under preparation is expected to require indoor concentra-tions of radon below 100 Bq/m³.

• Radonconcentrationsareagrowingproblem.High concentrations of radon gas can be harmful to humans. 15% of all cases of lung cancer in Norway are probably due to radon exposure, which makes it the second most important risk factor for lung cancer, next after smoking.

About the membraneProtan RadonSafe is a membrane that is produced in several layers.Top and bottom sides are consisting of TPO. In the middle there is the reinforcement of strong polyester fabric. This membrane construction ensures both good radon density and good strength.

Sheets of Protan RadonSafe membrane, corners and penetrations are welded together with hot air welding. This material selection and welding method ensures homogenous seams which are fully air sealed and of greater strength than the membrane itself.

Protan RadonSafe comes with prefabricated details and accessories to ensure that complex details are easily and properly sealed during installation. In addition, the installation is performed by professional roof contractors who have been trained by Protan.

Endnote from Sintef 12.02. 2010«Care has to be taken to ensure airtight joints, connections and feed-throughs at all places and no perforations of the radon barrier.».

B1 - Protan RadonSafe loosely installed under concrete

B2 - Protan RadonSafe between two layers of insulation

B3 - Protan RadonSafe under insulation

PP geotextile >100 g/m 2

Class B gives three installation options / opportunities

Radon Fact Sheet Product Name: Protan Radonsafe

12.02.2010 / BPJ, KNN

Ce

Cg

Ca n

AV

P = 1/R

Cm

S

q∆p

ν

Aw

P = 1/R

w

w

Product Information – Radon Barrier

Name: Protan RadonSafe Company: Protan AS Radon Diffusion Transmittance: 0.38·10-8 m/s [1] Radon Diffusion Resistance: 2.6·108 s/m [1] Air Permeance of Radon Barrier: Not measured yet [2]

General

The radon concentration in indoor air (Ca) has been calculated for the given product for various cases (fig.1), e.g. with respect to radon diffusion resistance (R), radon concentration in building ground (C g), air permeance of ground (q), air pressure difference between outdoor ground and indoor at ground level (∆p), indoor/outdoor air pressure equilibrium height (h), building (room) area towards ground (A), building (room) volume (V) and number of air changes per hour (n) due to ventilation, infiltration and exfiltration through walls and roof (as the floor is included in q). The term q∆pA represents the air leakage through ground (m3/h). Further details are given in Jelle et al. [3].

Special Requirements

For radon barriers with non-welded joints (e.g. joints sealed with two-sided adhesive tape and/or sealing compound), the requirement of the air permeance of the radon barrier is 5·10-4 m3/(m2hPa) carried out according to the measurement method [4], thus the air permeance of the ground is set to 10·10-4 m3/(m2hPa) in the calculations of the radon concentration in indoor air (may be subject to change). For welded products the corresponding values are 2·10-4 m3/(m2hPa) and 4·10-4 m3/(m2hPa), respectively. The maximum radon diffusion transmittance for obtaining a SINTEF Technical Approval is 4·10-8 m/s for radon barriers with welded joints and 2·10 -8 m/s for radon barriers with non-welded joints (may be subject to change). Today’s recommended minimum ventilation in Norwegian dwellings is 0.5 air changes/h, which is not fulfilled in many buildings, and thus a somewhat more conservative estimate of 0.25 air changes/h is applied in the calculations. The requirements have to be evaluated with respect to the ground radon concentration at the actual location, and other preventive and remedial measures against radon may be required.

Graphical Plots

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Radon Resistance (108 s/m)

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n C

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(B

q/m

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Radon

Gg = 50 000 Bq/m3

n = 0.25 h-1

V/A = 2.4 m

q = 10·10-4 m3/(m2hPa)∆p = 1.7 Pa

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Ground Radon Concentration (Bq/m3)

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Radon

R = 2.6·108 s/m

n = 0.25 h-1

V/A = 2.4 m

q = 10·10-4 m3/(m2hPa)∆p = 1.7 Pa

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Number of Air Changes per Hour (h -1)

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Radon

Gg = 50 000 Bq/m3

R = 2.6·108 s/mV/A = 2.4 m

q = 10·10-4 m3/(m2hPa)∆p = 1.7 Pa

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Air Permeance (10 -4 m3/(m2hPa))

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Radon

Cg = 50 000 Bq/m3

R = 2.6·108 s/m

n = 0.25 h-1

V/A = 2.4 m∆p = 1.7 Pa

Fig.1. Radon concentration in indoor air vs. radon diffusion resistance, radon concentration in building ground, number of air changes per hour and air permeance of ground.

End Notes Care has to be taken to ensure airtight joints, connections and feed-throughs at all places and no perforations of the radon barrier.

References

1. SP Technical Research Institute of Sweden, Report P605277, 2007. 2. SINTEF Building and Infrastructure, Report [not carried out yet]. 3. B. P. Jelle, K. Noreng, T. H. Erichsen and T. Strand, ”Implementation of Radon Barriers, Model Development and Calculation of Radon

Concentration in Indoor Air”, Accepted for publication in Journal of Building Physics, 2009. 4. SINTEF Building and Infrastructure Method 167/01, “Radon Membrane: Testing of Airtightness” (Radonmembran: Prøving av

lufttetthet), 2001.

Technical excerpt from SINTEF.Note End Notes

Technical dataQuality Values Protan RadonSafe Test method

Roll length 20 m EN 1848-2

Width 2 m EN 1848-2

Thickness 0,8 mm EN 1849-2

Surface weight 0,8 kg/m2 EN 1849-2

Tensile strength 1000 / 1000 N/50mm EN 12311-2

Elongation 15 / 20 % EN 12311-2

Trapezoidal tear strength 400 / 400 N EN 12310-2

Puncture resistance, Impact 350 mm EN 12691

Puncture resistance, Static load 200 N EN 12730

Dimensional stability ± 1,0 % EN 1107-2

Shear resistance of joints - overlap joints 800 N/50 mm EN 12317-2

Radon Diffusion Transmittance 2,2x10-8 m/s SP-method

Radon Diffusion Resistance 4,5x107 s/m SP-method

Detail of sealing against wall by use of Protan steelbar, airsealing tape or mastic

Detail of pipe sealing at building site by use of Protan RadonSafe-H

PROTAN RadonSafe-Hmembrane

Protan ASP.O. Box 420, Brakerøya, 3002 Drammen, Norway

Phone: +47 32 22 16 00 • info@protan.nowww.protan.com

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