MrDavid

Fair enough! Will put in RE w/ access from kitchen at that 90° at end of bath tub, are there any limitations on RE branch lengths? Option 1 is also my preferred route, but I have 2.6m existing FTC and am contemplating 100mm ceiling buildup to fit in recessed downlights, maybe more if I want to conceal duct route back from 1.07 to external wall. So all combined that squeezes 1.08 to 2.2m FTC which is not ideal. two branch connectors already exist going into that WP at 160mm AFFL and 440mm AFFL, so would like to split drainage flow between them to avoid blockages and yes this is schematic only, am going for 200mm bends on the 90s, does need some planning. testing is sensible! Thanks all for comments

Amazing thanks for the feedback Peter. Noted on the shower level, the drainage levels here may prove the driving constraint rather than WC soil, if I want to go for level shower tray. Do you see any issues with Option 1? A difference between the two options I neglected to mention is that Option 2 squeezes 1.08 by 100mm to return some wiggle room into the service area behind 1.07. There is an existing VP by the sink here that needs to be negotiated.

Hi all Looking for some advice on soil pipes, any help would be much appreciated! Drainage isn't my strength I'm renovating a 4 bed flat, looking to add a 2nd bathroom and rearrange the existing bathroom and kitchen. It's a 1920s ex LA building, has one external SVP and one internal WP. Some fundamental q's Can I connect 2 toilets to the same soil stack using 1 soil pipe? The existing stack was shown as 3.5" on the original architect's drawings but seems bigger in reality (I will check). And do I need AAV's for each toilet? The SVP vents to atmosphere above eaves level and this flat is on the top floor. Assuming that's all fine, does anyone have any comments on the following two options? Option 1 is to run a soil pipe in a service void below bathroom 1 with a raised FFL. Creates some Part K issues with the level changes, which are resolvable if not necessarily desirable. May bump up the hallway FFL so height difference is only 1no. 220 rise. Option 2 is to flip bathroom 2 layout and try to run the WC2 soil pipe behind the bathtub. However I am concerned this creates a lot of bends, especially in the connection back to main stack. I stumbled on this forum a few weeks ago as I was researching for my flat and am a big admirer of this community. After this I have a question on to combi or not to combi for 2 bathrooms, which I know is a favourite question for buildhub. Thanks