Capping Waste Pipe Query

[AMB96]

Hi all, so have an issue where the waste main down-pipe that runs through the centre of the house can often give off bad smell.

We think we’ve sourced the problem (see image).

What I’m not sure about, is if I cut and remove the copper pipe (we know this isn’t connected to anything) what kind of bung or cap should I get to seal this off correctly?

Direction would be really great as can’t stress how unpleasant the smell is.

 

[thomp1983]

You need to Id what size the hole is and if it's clear when the pipe is removed or full of silicone or some other gunk someone's used to try and seal that pipe into it.

But to fix it you want a pipe bung, there normally 32mm or 40mm like below,

https://www.screwfix.com/p/floplast-push-fit-socket-plug-black-40mm/52824?tc=NC3&gad_source=1&gclid=Cj0KCQjwsoe5BhDiARIsAOXVoUsncASQIsX1wgNnmwYpxy7FJwe6sYgVxEDiBxfvYLLlxP0t5HUpRQwaAgqUEALw_wcB&gclsrc=aw.ds

Long term you want something that's solvent welded in there but the push fit one is cheap enough to prove if it is the cause of your smell.

 

[Madrab]

It's not copper pipe, well not actual copper, it's just copper coloured plastic push fit, it'll be standard 40mm (not solvent weld)

The seal on the push fit coupler will have degraded and is no longer sealing properly. Can you get to the section of pipe that's coming up through the floor, cant see for the leg of the unit as you won't really know if its the top or bottom seal of the elbow that's the problem and if one's gone then the other probably has too

If so then you want to remove the push fit elbow and use one of these on it.

Compression Blank

 

[Hugh Jaleak]

Assuming it's 40mm waste, if you remove it the chances of getting anything to seal in the socket without some additional method of sealing are pretty slim sadly, I'd hazard a guess that pipework is the best part of 50 years old. Can you determine which end of the 'copper' pipe the odour is coming from? I'd be wary of touching the end going into the Boss pipe, as I suspect if you disturb it, any seal it has maintained will soon be broken.

If you can cut it further back without disturbing the Boss Connection too much, you should get away with fitting a compression waste cap as Madrab has linked to above. If this is not possible, or the seal in the photo is already compromised, then you dont have much to lose in that respect. Pull the waste pipe out, and fit a suitable size cap/rodding eye, but it'll probably need a liberal coating of silicone on it to seal it. Try and avoid letting any water down from above whilst the silicone cures.

A large jubilee clip strapped around the pipe/cap to hold it in place wouldn't go amiss either, will prevent accidental disturbance of the cap later down the line. .

 

[Madrab]

I'd be wary of touching the end going into the Boss pipe, as I suspect if you disturb it, any seal it has maintained will soon be broken.

That'll teach me to look properly - I didn't look at it properly and thought it was an elbow rather than a ring seal boss connector

 

[AMB96]

Assuming it's 40mm waste, if you remove it the chances of getting anything to seal in the socket without some additional method of sealing are pretty slim sadly, I'd hazard a guess that pipework is the best part of 50 years old. Can you determine which end of the 'copper' pipe the odour is coming from? I'd be wary of touching the end going into the Boss pipe, as I suspect if you disturb it, any seal it has maintained will soon be broken.

If you can cut it further back without disturbing the Boss Connection too much, you should get away with fitting a compression waste cap as Madrab has linked to above. If this is not possible, or the seal in the photo is already compromised, then you dont have much to lose in that respect. Pull the waste pipe out, and fit a suitable size cap/rodding eye, but it'll probably need a liberal coating of silicone on it to seal it. Try and avoid letting any water down from above whilst the silicone cures.

A large jubilee clip strapped around the pipe/cap to hold it in place wouldn't go amiss either, will prevent accidental disturbance of the cap later down the line. .

Thank you, as for which end, definitely by the boss pipe is our thinking.

We previously had a plumber come out to find (what is the other end that you can’t see) just had taped up and styrofoam inserted by the previous homeowner. That plumber put a cap on it but the odour comes from the base hence my suspicion. I don’t think I have much to lose so really appreciate the advice!