Kitchen Wastes

[IanShaw]

Is it acceptable to have a main run of 38mm waste pipe to the outside drain then connect 32mm wastes from dishwasher, washing m/c and sink unit into the 38mm pipe? This is to save running three separate pipes through the outside wall.

 

[Softus]

You can combine the wastes, but the minimum pipe size should be 40mm (inside diameter), not 38mm. I don't actually know where you'd get 38mm pipe.

Also, for the washing machine, you should fit a stand pipe if you can, rather than just tee in to the waste from the other sources.

 

[ChrisR]

If the common pipe is any length (over half a metre, say) then 50mm would be better.

 

[Dan Robinson]

Why not get a sink trap with two connections for dishwasher and WMC?

If is a long run then you might need an AAV.

 

[IanShaw]

Thanks for your suggestions guys, I'll probably go for the 50mm main run and stand pipes from the wmc and dwshr.

 

[IanShaw]

Thanks for your advice guys. Job done with 40mm main run, 1 stand pipe at end of run from dshwshr in 32mm and a connection into sink waste from wmc. All tested and ok. Many thanks. Ian S.