Push-fit water waste pipe ?

[Clive]

Hi,

The waste water pipe from the bathroom sink passes through the wall into a 90 degree bend on the external wall. Now as far as I can tell the bend is a push fit rather than a screw threaded type used on other waste water pipes at my house. Now this makes the fitting very "slim- line". However, the bend is partially "embedded" within a mortar rendering and the external "down" pipe has worked loose. I have pushed the external pipe back into the bend (tricky because it is jammed behind a vertical soil pipe). However, I don't think the pipe has fully "engaged" in the bend and I'm pretty sure it will work loose again. What's the best way to repair this permanently? I'm thinking of chipping away the morter and replacing the bend with some other fitting - but I'm not sure what to use or whether there is a much simpler way to make a good repair.

Any ideas would be most welcome.

Thanks

Clive

[Pete Verdon]

In my opinion the final result should be a solvent-weld joint. Made properly (and it's not especially hard) this will be permanent, robust, and neat. However, you can only weld to the right kind of pipe, and if your existing pipe really is push-fit then it will not be suitable.

That said, push-fit sounds a slightly unusual choice in your situation, and I wonder whether it's actually a solvent-weld fitting that wasn't properly welded and has failed. I had something similar on the front of my house; you could push the pipe into the socket where it would stay for a while before falling out again. When I finally got round to fixing it I cleaned up the inside of the socket and the outside of the pipe with fine sandpaper, and welded it properly. It's been completely solid since.

Pete

[Mike Clarke]

I'd agree with that. I recently discovered the major contributor to a damp problem in our kitchen was a leaking push fit waste elbow with the joint embedded in the mortar just below the outside surface of the wall.

[fred]

Just to add, solvent weld (ABS or muPVC) have slightly different nominal sizes from pushfit (polypropylene) so will not inter-mate reliably but universal compression waste connectors will make the join happily between the two if you have to cut out part of the old piping and mate it up with the new.

Solvent weld is defo the best for a through the wall situation like this.