What are the bedding requirements for PE pipe?
Customers normally advise that trench bottoms should be excavated to provide a reasonably even bed along the pipe length and free of sharp stones or other objects that could damage the pipe. Sand for pipe bedding should be used where possible and soil containing sharp, angular gravel or cobbles should not be used for bedding of PE pipe. The depth of the trench should be suitable to provide the required cover when reinstated.
PE pipes having a protective outer sheath (multi-layer) may be laid in heterogeneous ground without sand bedding thus allowing a wide range of excavated materials to be re-used.
Where the pipe is to be laid through rock or ground of variable consistency, customers normally advise that the trench should be excavated approx. 75mm below its normal depth, and a bedding material placed before the pipe to provide a bed of suitable consistency.
Where the pipe is to be laid through contaminated ground then the soil should be checked to determine if it would bechemically aggressive to PE. If necessary the aggressive material should be removed and imported bedding and backfill should be used.