Do you include the vertical run when deciding waste pipe diameter size?

[Madrab]

waterless trap

Had trouble with backing up before now with the low head volume in a shower, especially the Wirquin ones, more so with long hair.

 

[SJRSJR]

Thanks, I’ll put an anti siphon trap on the bathroom basin.

Back to the shower room and the long run. For peace of mind I’ll replace the 40 with 50.

Could the first horizontal run and elbow into the vertical stay as 40? I don’t know if you can see from this photo but the vertical pipe sits between three pieces of timber and I don’t think a 50mm will fit. I could do 50 from below but it would mean there’d be about 1.5m of 40mm plus the elbow running from the shower trap.

 

[denso13]

Yes, that would help.

 

[SJRSJR]

Thank you, that will reduce some of the hassle!

 

[robinbanks]

Had trouble with backing up before now with the low head volume in a shower, especially the Wirquin ones, more so with long hair.

Aye, me too.. Still searching for the perfect filter but I've found that wire wool pan scrubbers stuffed in the plug hole do a good job of catching long hair

People seem to rate Wirquin but I'm not so impressed; for low profile basin I like the Purus ones or HepVO if there is a bit more space, and I'm not averse to using a HepVO and binning or chopping the parts of a water filled trap so it's no longer a water trap, but I've created a bigger space for catching hair