As pressure increases to develop on, or adjacent to, land which was formerly industrial, derelict or used for landfill, measures must be taken to protect buildings and construction from the effects of gas.
This gas can be from several sources such as landfill gas, relict methane associated with coal measures, natural organic strata, naturally-occurring radon and sewage.
Guidelines for such measures are contained within Buildings Regulations Document C and Building Research Establishment Report BRE212 as well as Waste Management Paper 27. These guidelines recommend gas concentrations above which protection is required and this may be achieved using vent pipes in a granular blanket beneath the floor slab, either with a natural or forced vent extraction.
MGS's Demco division provides all the major HDPE pipework and other components for passive venting systems including:
