plumbing advice for connecting WC to 3.5" soil pipe

[maxim naumov]

hello everyone

I am renovating a bathroom and today I made an attempt to remove the WC pan to prepare the wall for plastering. after unwrapping a greased rag around the joint I discovered that the collar of the cast iron soil pipe is broken. one side of it has broken off and was held in place by that rag.

now I am quite puzzled what to do. the push-fit connector that I bought in a shop is AFAIK for 110mm PVC waste pipes. it is certainly too small for that collar. the outside diameter of the pipe is around 101mm (including paint) and currently I have no way of measuring the internal diameter because I don't want the family to be left without a toiled for too long. if I start dismantling the joint completely, it will start leaking badly and I don't have anything fix the joint just yet.

I looked at the soil pipe from the outside of the house and I think I can see '3 1/2"' written on it, although it is a bit difficult since it is covered in many layers of paint. I certainly don't see '4"' there.

AFAIU, the only way I can go now is to remove the remainder of the collar, find a suitable push-fit connector and use it to connect the pan. unfortunately, after some googling I could not find any suitable for 3.5" cast iron soil pipes, all seem to be designed for 4".

I need to temporarily remove the existing old WC pan, plaster the wall, put it back and when the floor/walls are ready, I can finally fit the new pan. I might need to offset the new pan to the right a little bit as well.

AFAICS, this soil pipe cannot be 4", since it's outside diameter should be a bit larger (~110mm?).

I would be very thankful for any input, preferably with links/stock numbers, since I am a bit new to plumbing, especially to UK plumbing. 8) sorry if I am not using proper British terms for things. are these collars on cast iron pipes still used when connecting WC pans?

thanks very much in advance.

/max

[A.Lee]

Snip trouble with toilet outlet pipe.

Go to a plumbers merchants (not B+Q), and they have many different types of convertors and couplings for mating up different sized toilet pans. They should have what you are after. Alan.

[maxim naumov]

Alan, thanks very much for your reply. generally, what do you do with that collar when installing a pan? AFAIK previously you needed it because the joint was mortared or something, but nowadays? it will get in the way when installing the coupling.

looking at my current installation, I see a ceramic part of the same colour as the pan, that is cemented into the collar, and the pan's outlet is inserted into it.

/max

[A.Lee]

They used to be,but when you change the toilet, the new one does not always line up with the pipe, so cementing it in place cannot be done. There are now a large range of different connectors available, which are a plastic pipe, with an internal rubber seal at one end for the toilet, and an larger exterior seal at the othe end which pushes into the pipe. If it is not a straight run, then some have got 'eccentrics' on them, so you can twist them round to get a good fit. See some here:

[maxim naumov]

so they are pushed into the *pipe* itself, not into the collar/socket thing?

/max

[John Rumm]

If you get the sort with the rubber fins on the outside at the pipe end then yes. Just stuff a length of the connector down the pipe and it seals against the inner pipe surface. (you can knock the rest of the collar off if you want). If you have a really difficult to mate up combination then the flexi connectors can work very well.

[Robert Laws]

I recently did something similar to this. the old loo joined a cast iron' extension bit' that was connected to a collar on the siol pipe. the joint was packed with lead. Following advice from uk.diy, I rented a soil pipe cutter which cut off the collar of the expension but for me (with a single loud bang). i then used on of the plastic inserts the previous poster described. it has fins on the outsode and jammed nicely into ther inside of the remaining iron pipe. I 'glued' it with sealant.

Now the new loo slides on and off the soil connect with a firm but smooth movement that is a joy to behold.

Robert

[maxim naumov]

good fun! 8) I assume your soil pipe is 4"?

thanks for the info! I think I saw your posting in search results on google groups.

/max

[Robert Laws]

Yes, and one should remember that diameter is the most important dimension. Having siad that, people who DIY may be less concerned about diameter and tend to focus more on length.

Robert

[Andy Hall]

I'm not so sure. I would have thought that most people would be happy with the smooth movement.

[maxim naumov]

done! removed the old pan/cistern, spent an hour with an angle grinder (very awkward angles because of the collar/walls/floor). then I had an inch of pipe sticking out of the wall. cleaned the inside of the pipe from fossilised ****. MAC-EXTB 3.5" to 4" extension went in there with a bit of force applied (mallet+wooden plank). then I discovered that the old pan's spigot was ~100mm in diameter, but very short (~15mm) and conventional connector (MAC-7A) did not fit. had to fit it straight into the extension. it is only temporary until I fit the new pan.

thanks for suggestions everyone!

/max

P.S. I even have pictures. 8)

[mike]

There's nothing like a firm but smooth movement where loos are concerned ;-)