Pipe Bedding — The Complete Guide
Getting pipe bedding right is critical. The wrong material under a pipe can cause it to crack, settle unevenly, or fail. Here's everything you need to know to do it correctly.
What is Pipe Bedding?
Pipe bedding is a single-sized, clean aggregate used to support and surround pipes in trenches. It's typically a 6mm or 10mm washed gravel or limestone that provides even support around the pipe without sharp edges that could damage plastic pipes. The bedding layer goes underneath the pipe, and the same material (or selected granular fill) is used to surround and cover the pipe before backfilling.
Common uses
- Drainage pipe installation (surface water, foul water)
- Water supply pipe protection
- Gas and utility pipe installation
- Sewer pipe bedding in highways
- Land drainage pipe installation
Sizes & grades
Class B bedding: 6–10mm single-sized clean gravel (most common for plastic pipes). Class D: selected granular material. Class S: granular material for self-bedding pipes. For most domestic drainage, Class B 10mm gravel is the standard.
How much do you need?
For a standard drain trench: allow 150mm bedding below the pipe, plus surround to 150mm above the crown of the pipe. Calculate trench volume minus pipe volume, then multiply by 1.5 tonnes/m³.
Pro tip
Never use sharp crushed stone or angular aggregate directly against plastic pipes. Always use rounded or smooth crushed aggregate to avoid point loading and cracking.
Suppliers of Pipe Bedding near you
3 suppliers in our directory stock this material.
Ashley Plant Hire & Building Supplies
Cheshire
Ground Materials Limited
Cheshire
North West Tippers
Cheshire