A key element of the government’s sustainable development strategy is to provide 60% of new housing on previously developed land or converted buildings by 2008.
This increases the uncertainty of ground conditions where there can be serious risk of contamination or from old foundations. More care has to be taken in assessing the requirements of sub-structures such as drainage systems.
There is a choice of two types of drainage system: rigid (clay or concrete) or flexible (plastic). Clay pipes with suitable choice of sealing ring are recognised by the industry as providing the surest system against contaminants. Research by CERAM in association with DETR has shown that clay pipes can be installed using recycled granular bedding and surround which is classified in the BRE Digest No. 433.
The combination of the structural strength and chemical resistance of clay together with available recycled granular bedding provide a cost effective sustainable solution to drainage on brownfield sites.