Floor type: Suspended floors and solid floor
One of the simplest ways of reducing radon is to create a simple passive radon barrier. Thick Damp Proof Membranes (DPMs) are the best known example of radon barrier protection.
Damp proof membranes and sealing floors
A DPM radon barrier should be at least 300 microns or 1200 guage thick to meet building regulations in the UK. Look out for the orange DPM which is often known as “Radon Approved” DPM, although other colours are available. These are also the specified minimum thickness stated by the BRE/UK Govt. It is recommended that a DPM of the specified thickness should be fitted in any new home or extension in a radon affected area, with a precautionary sump, to be able to fit a radon fan in the case radon levels remain high after occupation.
Sealing gaps and holes in the floor are also a well-known method of barrier radon protection. Sealing floors can be very labour-intensive, and may have limited impact, so if you have high levels of radon it may be best to consider other alternatives.
Blocking air flows up chimneys can be a good barrier method of remediation.