Drybase Liquid DPM can be applied to a substrate to provide Radon protection in accordance with BRE211 which states:

In areas with an increased radon potential, sufficient protection will be provided by a well-installed damp-proof membrane (DPM) modified and extended to form a radon barrier across the footprint of the building. This gas-tight barrier is known as basic radon protection.

Drybase Liquid DPM has been tested by Saarland University and was found to be Radon tight at 2 mm thickness.

To apply Drybase Liquid DPM for Radon protection, apply a minimum of 2 3 coats, allowing the previous coat to dry for an hour or so before applying the next coat. To achieve a 2 mm thickness the coverage of Drybase may be less than the stated 4.5 m² per 5 litres.

The second coat of Drybase Liquid-Applied DPM can be used as a primer for cementitious levelling screed as long as it is applied while the second coat of Drybase Liquid-Applied DPM is still tacky.

Alternatively, create a mechanical key on the Drybase Liquid-Applied DPM layer by sprinkling fine washed sharp sand or kiln dried graded quartz sand while it is still tacky.

If both the first and second coats of Drybase Liquid-Applied DPM have already cured, a further coat can be applied to act as a primer for levelling materials such as cementitious levelling screeds. Any subsequent layers should be applied while the Drybase Liquid DPM is still tacky.

Yes, however you will need to use be a polymer-modified tile adhesive.

Please ask the tile adhesive manufacturer for the thickness required and to ensure compatibility between the tile adhesive and Drybase Liquid-Applied DPM.

Cementitious levelling screed should be laid at a thickness of between 50 and 70 mm or greater. Always take into account BS8204, the manufacturers guidelines and the required load bearing capacity.

If more than occasional foot traffic or commercial use is expected, we recommend that the cementitious levelling screed is laid as a thicker layer.

The surface of the cementitious levelling screed should be finished according to the type of wearing surface or flooring that is to be laid.

If the use of a thin sheet or tiled floor is required, then the use of a self levelling smoothing compound over the cementitious levelling screed should be specified.

Drybase Liquid DPM is not UV-resistant and will lose adhesion and disintegrate within approximately 12 months if applied externally due to UV light. It cannot be applied to vertical surfaces.

Drybase Liquid-Applied DPM does not have a strong bond to the substrate and will therefore not strongly adhere to vertical surfaces. It may also slump if applied to vertical surfaces, making it difficult to add any water based finishes like plaster or paint on to.