How to cap off old kitchen waste gulley (kitchen extension)
Discussion
Fun times at Hustle Place as I have an infestation of drain flies which, despite cleaning out the P-traps and the external gulley, won t seem to FRO.
What wasn t clear was how they are getting in. Until yesterday. I pulled the plinth out from under the cabinets and found the source. There is a redundant kitchen waste gulley on what used to be the external wall where the kitchen sink presumably used to be before the kitchen extension was built. Now extended, the redundant gulley is now inside my kitchen underneath my cabinets.
It has been capped off with a bit of wood and sealed with mastic. Twenty-five years on, the mastic has perished and drain smell and flies are coming up.
What is the usual practice when extending like this? Is it normal to leave pipe work connected to the drainage and just cap it off?
In the face of it, re-doing the sealant would seem to do the job, but is this just a bodge on a bodge?

ETA: I have not attempted to lift the cap to explore yet but it feels loose. Taking it off is not a moment I am looking forward to.
What wasn t clear was how they are getting in. Until yesterday. I pulled the plinth out from under the cabinets and found the source. There is a redundant kitchen waste gulley on what used to be the external wall where the kitchen sink presumably used to be before the kitchen extension was built. Now extended, the redundant gulley is now inside my kitchen underneath my cabinets.
It has been capped off with a bit of wood and sealed with mastic. Twenty-five years on, the mastic has perished and drain smell and flies are coming up.
What is the usual practice when extending like this? Is it normal to leave pipe work connected to the drainage and just cap it off?
In the face of it, re-doing the sealant would seem to do the job, but is this just a bodge on a bodge?
ETA: I have not attempted to lift the cap to explore yet but it feels loose. Taking it off is not a moment I am looking forward to.
Something like this... https://www.screwfix.com/p/mcalpine-push-fit-drain...
Accelebrate said:
Something like this... https://www.screwfix.com/p/mcalpine-push-fit-drain...
Yes, clean the top few inches of the pipe to make sure it seals. I would take the kitchen unit out to make sure it was done properly.Don’t use an expanding plug - they are intended for testing and not permanent use.
Accelebrate said:
Something like this... https://www.screwfix.com/p/mcalpine-push-fit-drain...
I bought exactly this but mangled it trying to get it in. It’s a bit too big. The pipe is iron. Probably 4” nominal not 110mmhttps://www.amazon.co.uk/Fernco-Flexible-Rubber-En...
You should have just enough pipe protruding to tighten the clamp, just clean the outer rim as much as possible.
You should have just enough pipe protruding to tighten the clamp, just clean the outer rim as much as possible.
Hustle_ said:
Accelebrate said:
Something like this... https://www.screwfix.com/p/mcalpine-push-fit-drain...
I bought exactly this but mangled it trying to get it in. It s a bit too big. The pipe is iron. Probably 4 nominal not 110mm
Just a fairly meagre amount of washing up liquid. It did cross my mind. Might give it a go with another one, it does seem to be just the job.
Although I still wonder why one of these ain’t it
temporary test plug
Although I still wonder why one of these ain’t it
temporary test plug
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