MC-Proof Is Radon-tight

Jun 17, 2020

Present in numerous regions around the world, radon gas occurs in varying concentrations in the soil and will enter building interiors unless prevented from doing so by an impermeable barrier. Radon is a proven cause of lung cancer, so it is essential to ensure that this radioactive gas is prevented from ingress into living spaces.

Bitumen-free reactive sealant MC-Proof eco (formerly Expert Proof eco) from MC-Bauchemie has a high crack-bridging capacity and is radon-tight, as was recently confirmed in a certification test.

A previously underestimated risk

The particular danger with radon lies in the fact that the gas is colourless, odourless and tasteless and is therefore imperceptible. Radon concentrations can only be determined with special instruments in the hands of experts.

The result of the decay of uranium and radium, this once underestimated gas has been present in the depths of the earth for millions of years and, depending on the permeability of the soil, can rise to the surface. Once in the open air, the gas is quickly diluted and rendered harmless.

However, it can enter buildings through leaky foundation floor slabs, cracks in masonry or through cable and pipe penetrations to accumulate in the interior air. Radon concentrations are at their highest in cellars, basements or ground-floor rooms with no basement, thereafter decreasing from floor to floor.

According to the Federal German Office for Radiation Protection (BfS - Bundesamt für Strahlenschutz), the annual average value of radon concentration in living spaces in Germany, for example, is about 50 Bq/m3. Around five to ten percent of homes in Germany have values of over 100 Bq/m3 in their living spaces and about 0.04 percent have values of over 1,000 Bq/m3.

Preventing radon ingress

Together with the Federal German Ministry for the Environment, the BfS has developed a concept comprising protective measures designed to reduce radiation exposure to radon in living and recreational interiors. Germany’s new Radiation Protection Act states that building owners in areas with high radon exposure are required to implement effective sealing measures to prevent or significantly impede the ingress of radon from the foundation soil.

Such steps are mandatory where the annual average value of 100 Bq/m3 is exceeded. New buildings have to be provided with a continuous barrier throughout to prevent the penetration not only of ground damp but also that of radon, while leaks in existing buildings need to be identified and eliminated.

Reactive sealant MC-Proof eco provides protection against radon

MC-Proof eco, the fast-hardening, highly flexible and bitumen-free reactive barrier sealant from MC-Bauchemie, is not only suitable for waterproofing cellars, basements and rooms in contact with the ground against damp and water ingress, but also against radon – as has been confirmed by a certification test carried out in accordance with Technical Specification ISO/TS 11665-13 (Measurement of radioactivity in the environment - Air: radon 222 - Part 13: Determination of the diffusion coefficient in waterproof materials: membrane two-side activity concentration test method; 2017).

The measurements were performed with instruments calibrated by the BfS. The test confirmed that a 4 mm thick coating with MC-Proof eco is sufficient to ensure radon tightness. The test certificate was issued in January 2020 and is valid for five years.

Reliable proofing

MC-Bauchemie's structural sealant can be applied without primer on vertical, horizontal and inclined surfaces in cellars or basements, and on floor slabs, foundations and similar. The two-component reactive coating is also suitable as a waterproofing membrane in the transition to water-impermeable components and as a base level moisture barrier in splash water areas or for fixing protection and drainage boards.

In addition to its impermeability to water and radon, it is also carbonation-retarding and resistant to de-icing salts to EN 13687-2:2002-05. MC-Proof eco is easy to apply and can be both painted and plastered over.

About MC-Bauchemie
MC-Bauchemie Müller GmbH & Co. KG is a leading international manufacturer of building chemical products and technologies. Headquartered in Bottrop, Germany, the group of companies with over 2,500 employees operating in more than 40 countries around the world has – in the 55-plus years of its existence – consistently made a name for itself through the development of advanced solutions for the treatment of concrete and the protection and maintenance of buildings and structures.


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Saki M. Moysidis


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