Basin and Bath - same waste?

[markwm]

Is it perfectly ok for the basin and bath to use the same waste pipe? Currently re-arraging a bathroom which has 2 40mm waste pipes exiting the wall. 1 for bath, 1 for basin and I'd like to re-arrange them in such a way that the basin and bath waste go into the same pipe with a T junction.

This ok?

 

[mcniven]

Yes - just use commen sense and dont allow them to run onto each other, use the T as the run from say the BATH is approaching the STACK.

 

[kevplumb]

anti syphon traps aint a bad idea either

 

[cowley]

You don't say where they go into outside, do they join a soil stack or waste pipe?.
If they join a soil stack then they should be as they are not joined together, also sometimes joining a basin waste to a bath waste can give you a backsurge into bath.

 

[markwm]

Both 40mm pipes join a soil pipe on the outside.

I thought it might be a good idea to reduce the number of pipes on the exterior of the house while I had chance. I took the bath and sink out today and it seems the bath waste pipe is angled in the wrong direction. The slope is going the wrong way.

 

[Gunslinger]

i would say they were done seperately to avoid back wash issues into the bath and also to avoid having to fit anti-syphon valves