New kitchen drain pipework problem

[Lobster]

The proposed new location of a new kitchen sink is giving me some brainstrain. I really need to fit it against an internal, party wall which means that the drains are a bit awkward. The pipe would have to go right round the kitchen, to the right, attached to three walls, and then I'd still need to move the gully to the other side of the back door.

Pipe can't go straight out the back (party wall); can't go to the left (internal doorway in the way)

Now the other thing is that there is a step down into the room (about

4") at the internal doorway (see below), and in any case I will be raising the floor to make it level. Existing floor needs a DPC anyway, so this makes sense.

So - what I'm thinking, why not send the 1.5" drainpipe straight across the room buried in the new floor, ie straight to the gully as the crow flies? I can't find any info about doing this: is it do-able/reasonable? Would it simply be a case of laying the DPC underneath where the pipe would run, fixing pipe in position with adequate fall (how much?) and then just pouring concrete over the top? Pipe would need to enter the floor under the sink perpendicularly - what minimum level of concrete cover would be needed?

Thanks David

_____________________ | S | | | ID | | | | |_ BD __________|

X

ID= internal doorway S= proposed new sink BD= proposed back door X= position of gully outside

[bigcat]

why not?

I'd wrap something soft round the pipe so it can move a little, plastic shrinks and expands with temperature.

whatever youve got space for. Its not like youre putting heavy duty point loads under the sink.

A rodding eye might make life easier later. I'd also solvent weld any joints :)

NT

[Lobster]

Erm - well, just that I can't remember having seen it done, and wondered if there was a reason not to; and if so I'd rather know now at the early planning stage than after I'd set the pipe in concrete :-)

Thanks for the tips - sounds sensible.

David