Shared or dedicated waste pipes

[jez5577]

Hi all, first post on here so hello everybody! We're about to start fitting a bathroom on the first floor at the rear of our house. It's a Victorian terraced house so has an external soil stack on the rear wall which conveniently travels down the outside of the new bathroom wall. However, not sure if we should / can tee the bath, shower and basin waste into a single waste pipe (maybe a larger diameter waste like 50mm?) so that just one waste pipe goes through the wall and into the stack, which would keep the stack looking tidier which we'd prefer, or should we really run a dedicated waste for each all the way into the stack? Would be grateful for any thoughts / suggestions, thanks!

 

[Phil_Plumb]

the thing with teeing in something like a bath which has a large volume of water to discharge, into a pipe which has a sink with a low volume of water to discharge but from a height into a shower tarp which has low volume of water and a very shallow trap is that one or more of the above appliances can if too much fall is applied can suck the water from any of the other traps.

I would tee the basin in to the shower but i would keep the fall of the basin pipe as low as possibe so as to prevent any vacuum effect.

I would leave the bath on its own pipe.

Anyhow thats how i would do it!



edit note: bigger pipes may mean you can reduce the fall but not by too much though

 

[Gray0689]

Individual wastes for me every time

 

[Macca2009]

I agree keep the wastes seperate from each other. nothing worse than gargling from the sink everytime you empty the bath.

 

[AWheating]

if you tee any two together use anti vac traps or hepvo valves. Idealy keep them seperate or upscale the pipe size.

 

[jez5577]

OK thanks all for the suggestions... seems like the consensus is that we should try and run dedicated wastes so we'll endeavour to do just that! Ta