cover between crossing pipes

[dpmiller]

So I've a couple of places where soil  and rainwater pipes have to cross each other.  Invert depth at the treatment plant means that the soil pipes are basically on the surface at the current working level, and will have just on 300mm cover to FGL.

The rainwater pipes can be pretty much any depth below this, we've almost a meter down to our open and piped ground drains.

 

Before I go to the BCO and groundworks guy with a cunning plan for this, any easy answers or gotchas? I'm guessing that setting the pipes on pea gravel (or whatever single-size is offered) , wrapping in polythene and then haunching with dry kerb-mix ought to be the way? Or is it concrete slab time?

But what about crossings? I can't see anything in the Approved Doc about them... Is the upper pipe negated when planning for the lower one? so 100mm of gravel between them? or does there need to be a barrier of some sorts?

 

ta.

[Oz07]

Id have thought 100mm gravel be fine but by the sounds of it you want your surface water drains deeper to mitigate any protection on top of these

[MikeSharp01]

27 minutes ago, Oz07 said:

100mm gravel be fine

Cripes 100mm gravel sounds like something out of the flint stones any left over would make a great rockery.

 

[Oz07]

Cant tell if joke or...

[MikeSharp01]

1 hour ago, Oz07 said:

Cant tell if joke or.

Sorry forgot the emoji it was a joke ? as in 100mm lumps of stone rather than 100mm layer of 10mm pea shingle.