Soil Pipe & WC Connection planning problem

[rednaxela]

Hello All, its Alex the semi-selfbuilder.

My builder installed the new soil pipe from the sewer to the bottom of my extension wall when he did the superstructure last year.
The toilet arrived today, and I worked out that for the pipe to go staight up up the wall to branch off through the wall into the 1st floor toilet, would mean that the WC is too close to the right hand side wall in the on-suite when you sit on the loo.

I really need to position it 150mm to the left of the pipe, but not too far as it would then clash with the sink.

I would really appreciate any advice on the best way this ccould be achieved.

From looking in Screwfix I am wondering if I could use;
18625 (92.5 Access Branch) + 18833 (Bend Single Socket)
The access branch would point to the left with the socket plugged in then going through the wall?

Many thanks in advance.

Alex.

 

[rcs]

Hi Alex
Not a hundy on what you're on about but I'm assuming that you want the soil pipe to pop out of the wall in the right position so you don't have any boxing in to do? If so, you can offset the inlet through the wall with whatever 110mm fittings necessary provided you still meet the regs for those fittings (i.e the correct fall and no other inlets on the branch within the restricted zone etc.). An alternative would be to leave the pipe coming in and use a different means of connection to the lav but box in(there's all sorts on the market including flexible convoluted types) or change the lav for a side outlet. Have a dash round B&Q or local plumbers outlet and maybe see an ideal solution. Might be a better option than putting another hole through the wall.
rcs

 

[rednaxela]

Thanks rcs,

Don't have any holes in the wall as yet. I'm still planning. I tend to plan things during the week and then do it all at the weekend.

I don't mind boxing in at all, I just want to make sure my final design is the best to avoid blockages and last the longest etc.
I think I will do as you say and take a walk round all the shops to see what is available. I always worry about flexible pipes and how long they may last.

thanks again, Alex.

 

[TicklyT]

You may have trouble achieving a 150mm offset between pipe centres using a 90 degree branch because of the socket depth on the fittings.
Maybe a 45 degree branch would be better suited. It may be worth considering solvent weld if things are a bit tight, as the sockets are a bit
smaller.

This link has some useful dimensioned drawings of fittings:-
http://co-uk.wavin.com/master/maste...middleTemplateName=oc_middle_system_browse_II

 

[rcs]

Good idea Tickly, you could set the 45 deg fitting to the exact height up the wall to get the distance required (pythagoras theorem etc), then go through. I've had a bad experience with solvent weld in the past and so now use lots more solvent than looks right, but you know it's not going to leak.
The house that I'm renovating had an offset plastic fitting onto the 90 deg 'P' trap and it had been leaking for years (the type from B&Q). It also fell apart in my hands when I removed it......nice . Think it had only been on since the 90's.
rcs

 

[rednaxela]

Hi Guys,

Thanks for your advice.
Before I looked at your replys, I had been to B&Q and looked at the various fittings. From what I could make out, if I fitted a pushfit bend onto the branch, the bend section touching the wall would make the branch stick out so far on the wall, the clips on the branch would not touch the wall!

The 45 degree fitting sounds good... I'm not sure about the maths though will get the mrs to help..

I will go over to the builders merchant and take a look at the 45 degree fittings.

Changing the subject a little, I looked at flexible pipes from WC to Soil Pipe. Do they really work?
I would have thought a consetina plastic pipe would trap and build up lots of nastys and be a poor solution!?

Alex

 

[rcs]

I'm using the concertina type as a stop gap and it doesn't appear to have too much clag stuck in there after 3 weeks. I'd not want to use it as a permanent solution though.
As far as the pipe clips being off the wall if you use a 90 deg, you'd have to bed it into the wall somehow where it turns in. The 90 deg one I just changed was originally made from cast iron, set into the wall between 2 courses of brick, in a box type structure with slate as a 'lintle' at the top. My problem is that it's too far in and I can't get any clips in the gap as the vertical section of soil pipe was set too close to the wall when the drains were changed. It does look neat and tidy though.
Are you planning on cutting a 130(ish)mm hole or knocking out a brick or two?
rcs

 

[rednaxela]

I was planning to make up a timber template with lots of pre drilled holes in it, then fix it to the wall at my centre point and drill through each one with my SDS Drill.

With regards to bedding in, can you have the 90 deg and pan joint in the wall? or would I need to continue a small section of soil pipe through to the bathroom?

I must admit, I would be a little nervous having a solvent joint inside the fabric of the wall, as I haven't used this method before. When I'm learning something new, I like to be able to keep an eye on it.

 

[rcs]

My sentiments entirely. I always like to keep an eye on things too.
Depends on the proximity of the soil pipe to the wall, which like you say is going to be a bit of a problem anyway.
I can't see a problem having the joint in the wall space as when it's assembled, you could compo around the whole things which would allow you remove and install the pipe again if necessary (the compo would set around the pipe and provide a guide for re-installation, using care not to pick up too much debris that might damage seals etc.) One consideration would be settlement but filling the void with compo should help prevent undue pressure acting on the fittings.
Not sure what the regs are though. I remember our old house (1970's construction) having a 90deg branch fitting set in the wall.
rcs

 

[rednaxela]

You got me thinking...
Whatever method I use, I will need a joint in the wall as the clips would never allow enough distance for a branch or a 45 deg seal to sit just off the wall.

I'm going to invite the Mrs for a romantic walk around the village, while secretly I will be looking at every soil pipe I can find to get an average of how people have done it around here...
Its a secret walk as the Mrs would say i'm sad if I told her lol.

thanks again for all of your inputs. Will post my final solution.
My building inspector wants to see the design before I do anything anyway.

Alex.

PS, i'm not sure what compo stands for

 

[TicklyT]

Oops!
Just done the maths using the dimensions for a solvent weld 45 degree branch and a long tail bend trimmed so the throat of the bend sits against the socket of the branch , and the smallest offset I can achieve this way is 175mm.

I suppose you could lose the extra inch by tweaking the angle of the bend slightly out of true.

Another way to achieve a 150mm offset would be to fit a 90 (ish) degree branch with the inlet projectiong through the wall at an angle.

Why do some manufacturers quote the angle as 87.5 and others as 92.5?

Assuming the centre of the pipe is 100mm from the wall, and the wall is 300mm thick, a pipe through the wall at about 20 degrees from a right angle will achieve a 150mm offset where it passes through the inside wall. Trouble may be finding a 20 degree bend to straighten things out to connect to the pan, but there are 0 - 30 degree adjustable bends available.

If it's another 200mm to the pan spigot then 14 degrees would be enough, and there are pan connectors available with a 14 degree bend incorporated.

 

[rcs]

Compo is short for composition, i.e. made up of various parts. It's mortar, just another word.

 

[rednaxela]

I checked my layout and 175mm would be ok
The critical dimension is just to the left of the WC based on family voulenteers sitting on the loo and telling me the distance to the left of the wall they could live with. (want to get it right first time)

150mm extra was the best fit between the WC and sink.

thanks for doing the maths, your a star.
Alex.