Pipe Below Ground

Trenching and Bedding

uPVC pipe may be laid with the same as pipe of other material, detail of trenching and embedment will vary depending on the soil condition, authorities body or type of project. The trench should be as narrow as practical, but should be still sufficient to allow the proper placing and compaction of bedding material to fill at the side of the pipes. Recommended minimum trench width by standard is 200mm wider than outside diameter of pipes as showed in table 12.

Trench depth should be enough to allow for the bedding/underlay, pipes diameter and the minimum recommended pipes cover as showed in table 13. Particular attention should be given when the pipe passed under roadway or other load bearing structure.

Pipe Embedment Material

The material of embedment should be free from sharp edges to avoid scratch of pipe, sand or granular material are strongly recommended.

The embedment divided by three zone:

(as showed in following typical cross-section figure)

1. Bedding or underlay - The material directly under the pipe usually recommended 75mm to 150mm the thickness layer.


2. Side support - The material directly beside the pipes and top of bedding with minimum 100mm width are recommended.


3. Pipe overlay - The material directly the top of the pipes the minimum 150mm.