Protecting Underground drainage pipes (Ed.)

[willwillscrisp]

Hello, can anyone help with this question, I've got some 110mm underground waste pipe that are just below the hardcore of my extension, i can't lay the pipe any lower because of the fall of the main waste pipe. I don't want to lay hardcore on top of the pipe as I'm worried it could piece the pipe when i vibrate the hardcore. Can anyone help?

 

[DAZB]

It is very unlikley you will pierce the pipe as those things are tough but you could protect it with more pea gravel to give it a bit more cover and take it easier with the wacker over it.

 

[Hugh Jaleak]

What's going on top of it all? Normal practice would be to protect with concrete.

 

[Ivor Windybottom]

Remove it, clear a trench that's 300mm wide, run the compactor along the trench with a layer of hardcore in the bottom, re-fit pipe then make up formwork so you can encase it in concrete up to the top of the hardcore level. Give it a week then compact hardcore either side of it. Lay whatever's going on top of the hardcore (probably sand/DPM/insulation) straight over it.

You could concrete over it by 100mm then hardcore over, but I'm guessing that's near your hardcore level anyway, so better just to take it all the way up.

 

[willwillscrisp]

Thanks Hugh and Ivor. Think concrete is a good idea, just wanted to get it right before the BC inspector visits site. Thanks again

 

[noseall]

Thanks Hugh and Ivor. Think concrete is a good idea, just wanted to get it right before the BC inspector visits site. Thanks again

If you have the depth, bridge it with what ever thickness slabs you can put your hands on.

 

[Ivor Windybottom]

You'll probably need a rocker pipe where it leaves the building, to allow movement (or to allow the rest to move after the concreted in section can no longer move).