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Help moving soil pipe

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Hi,

Here I am again, this time refurbishing a downstairs toilet, which should be much easier than my 1 year elapsed bathroom refurbishment!

I'm installing the same Geberit Duofix frame and Duravit floating toilet that I installed in the bathroom and I'm having issues with the position of the existing soil pipe, which I expected to have to resolve, but would appreciate your expertise on the best way (and most economical way) to do this.

Here's a photo of the position I want to install the Geberit frame in the toilet:


As you can see the existing soil pipe position is too low and is slightly off-centre. The original toilet was installed off-centre for some unknown reason - probably laziness or lack of professionalism! Rough measurements suggest it needs to be raised by around 50mm and moved to the right by about 30mm.

So, my plan was to remove the existing soil pipe and expand the size of the hole to allow it to be moved into the required position. However, this obviously can't be done without also doing some work to the soil pipes outside, which look like this:


Fortunately, I don't believe I need to move the vertical soil pipe (left or right), just simply swivel it to the left as it enters the house and this should make it more central inside as at the moment it comes in at a slight angle. In terms of height, I will need to somehow lift it up around 50mm. The vertical pipe from the boss attachment is solvent welded, but the 90 deg bend uses pushfit. I need to increase the length of the straight piece of pipe from 100mm to 150mm, possibly less to include a fall away from the toilet pan.

I think I can achieve this by cutting the pipe half way along (where the horizontal black line is shown), leaving 2 x 50mm straights, which I can then re-connect with a coupler, which will increase the length.

The pipes are Wavin Osmasoil 110mm and Wavin make a solvent weld coupler, which is 155mm long and allows 50mm straights to be slotted into each end. So, as far as I understand, this would increase the height by 55mm? A little more than I need so this may not work. Wavin also make a push fit coupler, which is only 150mm long, so possibly a better length, but more "bulky". I could potentially replace the 90 deg access bend with a push fit version and replace the top straight, which includes the pushfit, with a piece of straight pipe. One end of the straight pipe would fit into the coupler and the other end into the push fit side of the 90 deg bend. I'm assuming the bend can be installed either way (pushfit vertical or horizontal). Doing this, would allow me to cut the straight pipe to the required length i.e. around 50mm plus the 50mm for the solvent welded end and whatever is required to fit into the pushfit side of the elbow.

Now that I've probably completely confused you, I would appreciate any feedback on my "plan" or guidance on how there might be a better way to achieve the required end result.
 
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Firstly, all 110mm pipe and fitting from across the Manufacturers is standard sizing, so anyone's pipes and fittings should fit anyone else's pipe and fittings. (You dont need to stick with Osma.)

Doubtful you'd be able to reuse the existing socket if the bend is removed, (seal will hardened and wont be any use), so I'd cobble up the required arrangement, then cut the existing pipe to suit. Solvent welded fittings are neater (and my preference for soil and vent), but assemble dry, check and double check it all lines up before cutting the existing pipe and/or gluing anything!
 
Firstly, all 110mm pipe and fitting from across the Manufacturers is standard sizing, so anyone's pipes and fittings should fit anyone else's pipe and fittings. (You dont need to stick with Osma.)

Doubtful you'd be able to reuse the existing socket if the bend is removed, (seal will hardened and wont be any use), so I'd cobble up the required arrangement, then cut the existing pipe to suit. Solvent welded fittings are neater (and my preference for soil and vent), but assemble dry, check and double check it all lines up before cutting the existing pipe and/or gluing anything!

I agree about not being able to reuse the existing bend, I found that with a soil stack I worked on last year when doing the bathroom refurbishment.

I purchased two 110mm Osmasoil couplings today:

4S104B - Double socket solvent weld. 155mm long according to the Wavin website.
4S105B - Slip coupler pushfit. 130mm long according to the Wavin website.

Having cut the existing pipe and cut the required holes higher up in the wall I found that I could only lift the elbow by around 35mm, possibly 40mm. This would suggest the solvent weld version would be too long as I have 2 x 50mm connections, giving an increase of 55mm (155 - (2 x 50)). This is why I also purchased the "shorter" pushfit, which at 130mm should do the job of raising the elbow sufficiently, without being too long. If I also replaced the elbow with a solvent weld version, I think I would be able to raise the elbow an additional 10mm as it is the push fit "lip" that prevents it going higher.

When I got the two couplings home, I measured them and found they are nothing like the quoted lengths. The solvent weld version is the shortest at 100mm and the push fit is 113mm. So, they are both actually too short for me to use!!!!

It looks like my only option is to replace the elbow, which means I can then use a longer straight piece of pipe to get the required height. Unfortunately, solvent weld access bends seem to be as common as the Javan rhino and I'm not getting one over the Bank Holiday, which is a bummer!

Why the Wavin website contains technical specifications that are completely wrong is beyond me.
 
If you’re struggling for an access bend, why not use an access pipe fitting and normal bend?
 
If you’re struggling for an access bend, why not use an access pipe fitting and normal bend?
Thanks for the suggestion, but I'm not quite sure what you mean by an access pipe fitting. Is this like a boss type fitting? I haven't got much room on the vertical pipe, possibly around 30mm beyond the coupling.
 
Ah, yes. Unfortunately I don't think I have room for that on the vertical as I also need to include a coupler. Also, as it is pushfit, I would need to use a pushfit bend and I think by using a solvent weld bend I get about 10mm extra height due to the lack of a "lip".
I've found an osma solvent weld 87.5 access bend on eBay so will probably go with that, but it means I can't finish the job until next weekend. Ah well, lots of other jobs to do.....
 

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