Waste pipe run length.

[dicky1971]

Hi,
I am installing a new shower, trying to get a fairly flush tray profile which will mean running waste pipes between floor joists. It looks like I am going to have a run of about 6-7 meters from trap to soil pipe,(it has to navigate a pitched roof outside) via sink and bath. I am able to get the required fall but I wonder if this run is just too long.
Am I hung up on asthetics and should I just sod it and build the shower up in a little tower and expose ALL the pipes in the bathroom...infact why bother tiling etc!! Sorry had a very long day nostil deep in plaster dust looking for hole potential in my wall.
Cheers

 

[Nige F]

"Via sink and bath".........picking up all 3 together?.......you could get away with it in 50mm and access points for cleaning...but it`s not good practise.

 

[chrishutt]

Sounds OK to me. You can check the Building Regs (ODPM) for acceptable limits on waste runs but in practice a 40mm pipe from a shower will not run full bore so no syphonage, etc. Just don't join in other waste pipes to the shower waste or you'll get water backing up into the shower tray.