I am replacing a bathroom suite which has a soil stack pipe dia. of 3". (..its been mentioned that rainwater pipe was used!?)
To keep things simple I have managed to get Marley fittings to do the job which are slightly larger dia.
How can I fit the larger dia. Marley pipe to the older smaller pipe (..about 3mm) ..this only needs to be connected at the ground level soil stack.
I also have a Wickes Soil Vent valve unit for use internally..fits on top of the soil stack ( which runs up to through the loft and exits onto the roof.)
Because of the pipe dia. probs. I assume I can use this "new" soil venting unit which fits using an adapter. ???

Any help appreciated...thanks!

Are you sure that it's not just the vent pipe that is 3"?

This was done quite often a few years ago on the vent pipe only as it was an acceptable minimum size.

I will measure asap...the fittings are/were Osma.

Thanks for the advice scruff....but Plumbcentre do not stock Osma now!

[quote author=wotamess  link=1124152592/0#6 date=1124267362]Thanks for the advice scruff....but Plumbcentre do not stock Osma now! [/quote]


Plumbcentre stock polypipe which is made by osma.

75mm OD is definitely non-standard for soil pipework. Is this the OD of pipe or fitting? If fitting, it might be a socket for 68mm rainwater pipe. Can you check this?

If it really is soil pipework, you could try adapting to it with one of these http://www.flexseal.co.uk/products/fern-straight.htm

What about the link I gave you? No good?

I'm still curious about where this 75mm OD Osma soil pipe came from. Have you asked Osma (Wavin Plastics) about it? If they can supply a socket, the socket might just have an OD of 82mm! Then you could connect using standard soil fittings.

Osma still sell 3" plastic pipe and fittings, I've bought it in the past. It's not the sort of thing that can be picked up at your local Plumb Center but it is still made.

The 3" is equivalent to your 75mm measurement.

I think you guys must be referring to the normal 3" soil pipework which has an outside diameter of 82mm. The poster needs something to match soil pipe with an OD of 75mm. If you have something with 75mm OD please give details.

By the way, Wotamess, do you realise that you can't discharge a  normal WC into 3" (82mm OD) soil pipework? The pipe must not be smaller than outlet of WC (normally 100mm). So I think you may have to dig down to drain connection anyway.

Picture posting information here

btk

First pic..
http://img246.imageshack.us/img246/5681/13ow.jpg

Help!...just posted a photo, but its taken up the whole post box

Try this!

Photo 2

Photo 3 again

Interesting use of silicon grease  

What have you actually used to seal the joint with

[quote author=wotamess  link=1124152592/30#31 date=1127337211]..sorry that should have read "sealant" not grease..I assume thats OK? [/quote]

No it won't last, solvent weld or gap cement is what you should have used.

Really think you ought to make the soil pipe 4", for all the running about you've been doing, you could have dug it up by now