WC waste

jasonmav · 16 Feb 2026

Hi, hoping to get some advise,
Currently replacing toilet but due to new higher floor level and toilet type, waste pipe from WC to soil pipe does not match up for a simple straight connection.
What is the recommended solution to do this now? Flexi?

Black pipe from toilet frame is 90mm.
I have an adapter supplied to push into grey soil pipe to reduce down to 90mm if needed.
Should I just use a McAlpine flexible pan connector from 90mm WC pipe straight into soil pipe? Or is there a better more secure way?

Many thanks for any advise!

CountryFan · 16 Feb 2026

Wouldn’t go flexible. Maybe extend the grey coming out and 45 into the black on the frame, or offsets?

Madrab · 16 Feb 2026

I think a 45deg bend on the grey with the 90mm adapter on it and then angle the frames soil pipe down @ ~ 45 deg and trim both pipes to fit. Given the rise on the grey pipe it may not be quite 45deg but should be close enough to fit by the looks of it.

denso13 · 16 Feb 2026

Slow bend from the branch to suit and keep it all solid, or use a flexi, whatever you prefer. I'm doing something similar just now.

Hugh Jaleak · 16 Feb 2026

An appropriately angled 110mm bend and cut the pipework to suit. Assuming it'll all be boxed in, so if you need a shallower angle, Underground Drain bends are available in shallower angles, 15,20 and 30°, if any of those would suit the application better.

jasonmav · 16 Feb 2026

Thanks all, I will try measure up the angle and sort it all in solid pipe.
I was mainly concerned about going too steep an angle, as don't want water flowing too fast. But presume that's more for down the line rather than nearer WC end?

denso13 · Tuesday at 8:36 AM

Not a problem for such a short length.

Hugh Jaleak · Tuesday at 11:44 AM

jasonmav said:
I was mainly concerned about going too steep an angle, as don't want water flowing too fast. But presume that's more for down the line rather than nearer WC end?

Momentum of water coming out the WC when it's flushed will ensure nothing is going to hang about that close to the outlet. Problems arise when People try and defy the Laws of Physics, and expect sh1t to run uphill, or travel along a horizontal run....

jasonmav · Tuesday at 2:07 PM

Hugh Jaleak said:
An appropriately angled 110mm bend and cut the pipework to suit. Assuming it'll all be boxed in, so if you need a shallower angle, Underground Drain bends are available in shallower angles, 15,20 and 30°, if any of those would suit the application better.

Underground 15° double socket was the solution.

Hugh Jaleak · Tuesday at 10:57 PM

Spot on. Glad you've got it sorted.

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WC waste

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