Soil stack (internal) connection to clay elbow at floor level.

[Mattg4321]

Late 60’s build. Got a soil stack - plastic 110mm connecting directly into a clay 4 inch elbow at ground level. 
 

Unfortunately and obviously, the OD of the plastic is smaller than clay pipe so it doesn’t fit properly. It will have been like this since built. I’m thinking there used to be mortar around the joint to seal, but this has failed over the years. When toilet is flushed you can see it slightly bubbling around the join and it’s very slightly damp, but not affecting surrounding area. However, I’m worried about what happens if the pipework backs up. Surely that join needs to be waterproof!!

 

How should I rectify? See picture below. Thanks in advance. 
 

 

[Mattg4321]

To add, not sure what’s at the bottom of the plastic. Some sort of metal, but not sure exactly what. 

[BadgerBodger]

If you are willing to remove the PVC and re- plumb… Either band seal which comes with a variety of OD variations or you might have some luck with a male/female adaptor.

 

It looks like the installer wrapped the plastic in some Denzo tape and just shoved it in. If you think it had a mortar point you could always reinstate that.
 

 

 

 

[Russell griffiths]

Is that an accessible area, can you always get to it ?

would you like to put a rodding point there for future blockages

or just patch up what’s there. 
 

[Mattg4321]

15 hours ago, BadgerBodger said:

If you are willing to remove the PVC and re- plumb… Either band seal which comes with a variety of OD variations or you might have some luck with a male/female adaptor.

 

It looks like the installer wrapped the plastic in some Denzo tape and just shoved it in. If you think it had a mortar point you could always reinstate that.
 

 

 

 

I think both those adaptors are designed to go in a clay pipe, not a clay fitting/elbow?? Got a link to band seal please? Thanks 

[Mattg4321]

13 hours ago, Russell griffiths said:

Is that an accessible area, can you always get to it ?

would you like to put a rodding point there for future blockages

or just patch up what’s there. 
 

It will be boxed in so just want to patch up/sort out what I have properly

[Onoff]

Is is external? I had to deal with this. A nice bathroom with new tiles sat straight on top of an old clay elbow:

 

 

 

 

I made a ply template first to drill and neaten the ragged hole in the tile and substrate:

 

 

Then used a Floplast, finned adapter Screwfix stock number 15330 I think) that went down inside the clay pipe. Found it better oddly that a McAlpine one. Principle is the same for yours. You just need the 110m to finned adapter:

 

 

I finished off with a really neat bead of BT1 after the last picture. 

 

That and actually screwed the pan down properly! 

 

For yours maybe this:

 

https://www.wickes.co.uk/FloPlast-110mm-Black-Universal-Pipe-Connector/p/158824

[Mattg4321]

4 hours ago, Onoff said:

Is is external? I had to deal with this. A nice bathroom with new tiles sat straight on top of an old clay elbow:

 

 

 

 

I made a ply template first to drill and neaten the ragged hole in the tile and substrate:

 

 

Then used a Floplast, finned adapter Screwfix stock number 15330 I think) that went down inside the clay pipe. Found it better oddly that a McAlpine one. Principle is the same for yours. You just need the 110m to finned adapter:

 

 

I finished off with a really neat bead of BT1 after the last picture. 

 

That and actually screwed the pan down properly! 

 

For yours maybe this:

 

https://www.wickes.co.uk/FloPlast-110mm-Black-Universal-Pipe-Connector/p/158824

Thanks very much for taking the time to write this substantial reply!

 

It’s an internal soil stack. To be boxed in asap. 
 

The finned pipe connectors are for fitting inside a clay PIPE, not a clay FITTING/ELBOW like I have? (apologies for caps)

 

My clay elbow is designed for a clay pipe to fit into it? A complete cock up by the original builders in the 60’s imo. 

[BadgerBodger]

5 hours ago, Mattg4321 said:

I think both those adaptors are designed to go in a clay pipe, not a clay fitting/elbow?? Got a link to band seal please? Thanks 

 Sure, this is the band seal catalogue. There are a seemingly infinite number of variations on the theme…

 

 http://www.dureycastings.co.uk/uploads/DOCS/naylor-bandseals-brochure.pdf

 

They can be bought from pretty much any builders merchant although they may carry a different manufacturer such as flexseal. The benefit with this is they are quite a tolerant connection in relation to size and position.

 

 

Whilst the products  I posted may not specifically be the correct arrangement alternative variations on size are generally available, you just have to take your measurements and search for them.
 

 

[Onoff]

39 minutes ago, Mattg4321 said:

The finned pipe connectors are for fitting inside a clay PIPE, not a clay FITTING/ELBOW like I have?

 

Your correct I think but I've no idea what that existing, leaky "adapter" is that connects the grey 110mm to the clay elbow. Have you a Vernier caliper to give some ideas of diameter? 

 

I wonder if this "4VFC2P" would work, as in get rid of the old adapter then fit this with a good slug of CT1 or similar:

 

https://www.drainfast.co.uk/products/underground/drainage/110mm/4110mm-dsocket-clay-plastic-adaptor

 

[Mattg4321]

Thanks both of you. I think those adaptors are for connecting clay PIPE to plastic. Not clay fitting to plastic. I don’t believe there’s a fitting for that. If there is, I certainly can’t find it. A design cock up from when it was built. 
 

I’ve just had a look at the connection for my downstairs loo and appear to have similar. Just pointed up with mortar. Which seems to prove my theory that is what used to be at bottom of soil stack. 
 

I think I may well run a bead of ct1 or similar round it to seal the inside edge and then point up what’s left. Cant see that leaking. I can’t really see a better option and it’s quick cheap and easy as a bonus. 
 

 

[gaz_moose]

they do those rubber joiners like in badgerbodger's post in big sizes like you need. I bought one by mistake a few weeks ago from a builders merchant.

Although if it were me i would just put mortar around it like the other one, id probably put some SBR in the mortar too.

[Onoff]

The mortar collar in your second picture was a very common method.  Looking closer at your first picture it appears there's some small bits of stone / aggregate left and the rest has broken away?

 

If you don't want to remove / re-do, then if that's just mortar at the bottom I'd vacuum /scrub/clean it as best as and re-mortar any gaps after wetting with SBR. Then I'd paint with this, maybe even form a little brim at the bottom with tightly wrapped dpc and pour in so it self levels which is one of it's properties. More flexible than a mortar collar I'd reckon. 

 

https://www.wickes.co.uk/Gorilla-Black-Waterproof-Coat+Seal---473ml/p/263581