Backfilling drainage question

[Jimmy Conway]

To cut a long story short........

I'm fitting some drainage in garden and will need tobackfill a trench containing 110mm solid plastic terracotta coloured pipe.

Depth of pipe will go from approximately 250mm to 500mm.

My soil is heavy, but not clay.

Finished project will have paving slabs laid on top.

What is the best material and procedure to bed the pipe on?

What is the best material and procedure for backfilling?

Struggling to find an answer online.

Thanks.

[seanandruby]

At that shallow depth( 0.6 minimum for plassy pipes ) the pipes should be encased in concrete, a movement joint should be placed at each joint. If the as dug material is acceptable with no large lumps, dry and free from organic matter, you can backfill with that, compact it well to capping level then start your sub base.

[Jimmy Conway]

Sean,

So I should be OK to backfill trench with the material I removed.

Would you recommend bedding pipe on a wet concrete to make finding its correct depths easier?

Thanks

[seanandruby]

Semi dry not to wet as it will float. Haunch over pipes windrow style.