Soli Stack toilet socket

Joined
4 Jul 2025
Messages
5
Reaction score
0
Country
United Kingdom
Hi,
I recently removed my toilet, as part of fitting a new bathroom, and purchased a new toilet.

The problem I have is that the new toilet waste port is approx. 190mm (centre) above the floor. But my original soil pipe port is about 225mm
I think this is a no go, due to gravity and all that, plus its hard getting any fittings to align correctly.

My soil stack runs from the kitchen up through the bathroom and into loft. Then out through the roof with a T piece join for the toilet in the bathroom.
Not only is the height wrong but the T piece comes out as a strange angle. (As in rotation, not horizontal)

I have a few questions:

If I cut this out and replace the T piece, what would be the best height (Centre) for the socket where the toilet would fit into. How much lower should this be for best results.
The toilet is only about 10 inches for the T piece socket.
Bear in mind that I can't go to low due to other restrictions, like the kitchen ceiling below, but I could go maybe about 100 or 120mm lower. And of course I do need the fitting or fittings from the toilet to align without too much of an issue..
The toilet itself is also at 90 degree to the soil pipe. So the pipe needs to come out of the back of the toilet, turn left to go into the soil stack, which hopefully will be lower with the new T piece.

Also, if I cut out the the T piece, what the best method to fit a new one without disturbing or replacing the whole stack too much.
I thought using some sort of slip joint above and below. If that is ok, should that be solvent or ones with seals.

Now the lower joint would go over the bottom part of the exiting soil pipe. Is that right? To me it would be better if it went inside somehow to help prevent leaks (Or use solvent or the best seal fittings).
The upper new joint would be ok because it is above the T joint and only goes out through the roof, so a slip joint with seals should be ok.

Also, what is the best method of cutting the soil pipe square while its in place (As in cutting the old T piece out, but keeping it square).

I would really appreciate any general advice on the best options here.

Thank you.
 
Can't you just remove the 10" of pipe from the T and fit a flexible pan connector ?
 
You ideally need 25mm of fall (slope) per 1 metre of horizontal run, so work out the distance from the centre of the Pan outlet to the stack, to see where you need to be, mark that height as the centre line of where the Junction needs to be.

If you cut above the existing junction, that should allow you to remove it, along with the section of the existing stack up to the cut. Work out where your new junction needs to sit, cut and chamfer the pipe at the required position. If you use a 'normal' coupling here, fitted correctly it wont leak. Fit new junction and section of soil pipe to meet existing stack, use a slip coupling on the top joint to rejoin the pipework.
 
Thanks for your replies.
What I think I need is a single socket solvent weld fitting for the bottom section.
Ideally the weld part to go inside the existing lower half of the soil stack, once I have cut it, leaving a socket for me to connect everything else to.
With it going inside and welded it wont leak. And as it goes inside the lower part, it will ensure it wont leak, as waste in unlikely to down and back up the joint.

But I can't find any info on this. Most places sell a single socket fitting with one solvent weld end, but I hope this goes inside the stack instead of outside.

Makes more sense to me but are these available or do they go over the existing soil pipe?

does that make sense?

Thanks
 
This is what I mean,
My question is: Will the weld end go inside the the soil pipe or over it? I want it to go inside. Looks like it should because of the ring on the outside.
1751699574301.png
 
If it's glued on properly, it will never leak. Liberal application of Solvent Weld adhesive, to both surfaces, wipe off any excess after making the joint.
 
Thanks, just wanted to make sure it was the best option.
I have purchased everything I need now, so will get this done tomorrow.
I know its not difficult or complicated, but its just very awkward to get to, so really I wanted to be prepared before ripping things apart.
Thats my Sunday, taken care off :D
 
If it gives you a little more confidence, we were discussing on another post yesterday about the Key Terrain brand of soil pipe and fittings, this was all solvent weld stuff. Even have it on my house, and of course, naturally it doesn't leak!
 

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top