Running soil pipe through stepped floor void

[jayc89]

We're going to have 2x ensuite's back-to-back, one stepped approx 200mm below the other. The lower void being the nearest to the SVP. I need to figure out the best way for the internal soil pipe to navigate this step down. 2x 90 degree bends might work (not sure if I have the clearance for that within the void), but are two bends and two changes of direction in quick succession suitable? Don't fancy any blockages!

 

Any suggestions?

[Conor]

Use 2x45s and create a void at the juncture between room #1 and room #2 if required. We had to do this but luckily all hidden above kitchen units, just built a bulkhead above right to the ceiling. What's your floor structure and do you have a suspended ceiling for services?

 

Edited September 27, 2023 by Conor

[jayc89]

4 minutes ago, Conor said:

Use 2x45s and create a void at the juncture between room #1 and room #2 if required. We had to do this but luckily all hidden above kitchen units, just built a bulkhead above right to the ceiling. What's your floor structure and do you have a suspended ceiling for services?

 

 

 

Ensuite #1 floor is solid joists, Ensuite #2 floor will likely be pozi joists. In both cases the joists will run the "right" way. I.e. left to right in the diagram. Neither have suspended ceilings below. I could probably box in within ensuite #2 to avoid anything in the rooms below. 

[ProDave]

If the 330mm brick wall is not built yet, build in an opening, bridged at the top with a lintel, to create a space for the pipe to rise between rooms.

[jayc89]

1 minute ago, ProDave said:

If the 330mm brick wall is not built yet, build in an opening, bridged at the top with a lintel, to create a space for the pipe to rise between rooms.

 

Unfortunately it's already there. It was once the external wall of the original part of the property, which is probably why the floor is stepped after that, but doesn't really explain it!

[jayc89]

Secondary question, do I need any sort of AAV to the left of Ensuite #1, or is the vent on top of the external SVP enough? (The vent is already higher than any new W/C I'll be fitting)

[jayc89]

Third question - is 100mm solvent weld "a thing"? My BM is struggling to get hold of any, my plan was to have my bath/shower/basin drains all connect into the 110mm pipe using branches and reducers. I'm assuming 110mm solvent weld pipe is like 32/40/50mm pipe and differently sized to 110mm push fit pipe, so mixing the two wouldn't work? (I'd prefer solvent weld everywhere internally and somehow converting to push fit externally)

 

[crispy_wafer]

Might not be the BM's goto brand but Floplast have 110mm solvent, I'm sure OSMA aswell

 

110mm Solvent Soil | Floplast

[jayc89]

This is the sort of thing I was thinking;

 

 

All internal plumbing is new, which I'd prefer to do in solvent weld, the SVP already exists and is push fit. I could probably run the single shower run in 40mm, but I'd have plenty of 50mm pipe left over, so why not!?

[TonyT]

https://assets.publishing.service.gov.uk/media/5a80cf9ded915d74e33fc8ae/BR_PDF_AD_H_2015.pdf

[TonyT]

Keep the shower 50mm