Precautions against radon
As radon is a contaminant, it falls under requirement C3 of the building regulations that states, “Reasonable precautions shall be taken to avoid danger to health and safety caused by substances (including contaminants) found on or in the ground being covered by the building.”
It is stated in Technical Guidance Document C of the building regulations that measures should be taken to protect new buildings from radon entering from the ground.
New builds, high-radon areas
Any area where the RPII national survey indicates that more than 10% of the houses are likely to have a radon level exceeding the NRL of 200 Bq/m^3^ are considered high radon areas.
The provision of a sealed radon membrane of low permeability combined with a potential means of extracting radon from the substructure such as a standby sump or sumps with connecting pipework is a typical method of protection. If a post-construction survey indicates that the actual radon level is greater than the NRL, the sump(s) can be activated by the installation of a fan.
New builds, normal radon areas
Any area where the RPII national survey indicates that less than 10% of the houses are likely to have a radon level exceeding the NRL of 200 Bq/m^3^ are considered outside high radon areas.
A sump(s) along with connecting pipework terminated and capped at appropriate points outside the external walls or in the attic space should be provided. Clear and permanent markings should be placed on the pipe terminals from the radon sump that state their functions. If a post construction survey indicates that the actual radon level is greater than the NRL, the sump(s) can be activated by the installation of a fan.
Radon membranes
Installed radon membrane
Image - Typical installation of radon membrane
TGD C also recommends that all radon membranes have independent certification from an approved body such as the National Standards Authority or Ireland (NSAI) Irish Agreement Board (IAB),
Minimum performance levels
The parameters listed in the table below should be certified.
Table HR1 - Minimum performance level for LDPE radon proof membranes - Extract from TGD C
Parameters, minimum performance levels, and tests for LDPE membranes are listed above. For non-LDPE membranes these tests may vary. However, performance levels should equate.
