Every so often we get a foul smell it the kitchen. It only last for a few minutes and doesn’t seem to eminate from the sink.

You can smell of most strongly under the sink which is next to the soil pipe. The smell isn’t triggered by flushing toilets or anything in the house, although there is a manhole just outside the back door next to the kitchen ( which is running clear). Seems worse at peak times, so in the morning when I guess everyone upstream from me are doing their business.

There is no vent on the roof but (I assume) an internal durgo valve under the bath (it’s all boxed in so don’t want to start pulling it all apart unless I know for sure that that might be the problem).

There’s no back up of any kind and the bath drains quickly.

Seems odd that it’s intermittent and not triggered by anything internal to the house.

Any ideas?

Thanks.

We get a similar thing occasionally coming from the cupboard under the sink which is about were the main soil pipe goes underground – we have two but never noticed an odour around the second soil pipe but that only really services one toilet. Never really been able to pin it down to something we’re doing. Neighbours and others on our estate seem to have similar instances. Not really a major issue, just the occasional wiff so not really worrying about it too much. I think it might be due to the massively expanding housing projects in the area, it much have an affect on the entire system when you suddenly bolt on thousands more homes to the infrastructure without upgrading what’s already there with funny back pressure things going on.

Did have an issue once several years ago, again during a phase of house building nearby, where we got bubbles of pretty rank sewer smells comeing up from our downstairs toilet. Others around us got the same thing. Something to do with back pressure in the system. They did some pretty major works to the system over a week or so and never had an issue since, so that is why I suspect it’s linked to the massive expansion of housing developments going on at the moment over the last 15 years and continuing for the foreseeable future.

Could be partially blocked drains – builds up during peak times and then gradually clears.
Do you have shared drains? – if so they are the responsibility of the local Water Board. Call them and they should clear them for free.

Very occasionally we do too, but I found it’s when the dishwasher clicks into drain mode.

If you have shared foul or combined sewearage (ie if more than one property drains into that manhole) then ring your water company who can come and CCTV your lines and see if there is any blockages or faults in the system. If it’s working properly you shouldn’t get smells.
If it’s working properly then the water company may be able to fit a cover which stops the smells coming through.
This is my line of work!

We get this too, found it comes up out of the washing machine drain pipe.

That’s really useful, thanks.

Check it’s not floorboards rotting under the floor covering. Guess how I know this?

Exactly the same scenario here OP. In fact, I initially read your post and thought “I don’t remember writing that” until I realised it was in fact, not me.

We live in a 1930’s semi with an extension the previous owners built about 15 years ago. The sewage smell in the kitchen was really quite bad at times. There is a crawl-space underneath the kitchen floor and from what I understand there is basically nothing under the wooden floor- just a sort of 3ft tall cavern with soil and rubble underneath.

We had a guy round who put a camera through the sewage pipe from the manhole outside and there were a few cracks which he says he sealed from the inside using some sort of liquid/slime jetting equipment. It costs a few hundred quid I think.

This did improve the situation but not totally. I think the main culprit was a quite severe bend in the waste pipe from the downstairs toilet. Seems there is a tight bend there and so the waste can become trapped when flushed. We were told that one way to clear it is to fill the bath and then empty it say once a month as this causes a torrent of water to (hopefully) clear the pipes. We only ever take showers so this action was never done as a matter of course before.

In any event we just stopped using the downstairs toilet for..um…number 2’s and this seems to have largely worked though its more of a compromise than a perfect solution.

I wouldn’t say I am 100% happy with the situation now as I’m still not really clear in my head on what is happening underneath our floor. If the sewage pipes under the house are completely sealed without cracks I don’t understand how we would smell the waste even despite the fact there is an empty crawl-space below the kitchen floor.

But at least my kitchen doesn’t smell of sh**t anymore which is the main thing I suppose.

We have a similar issue since getting building work done on the house. Using one of our two en-suites causes a rank smell in the main bathroom (central between the en-suites). Waiting for an air admittance valve to be fitted but I am not optimistic. I think we are going to need a new soil vent pipe.

Bit of an update in case it helps someone with a similar problem.

Turns out that the smell was escaping from the soil pipe through another pipe that was connected into it (from the macerator toilet).

I don’t know if it was the vibration from the macerator over the years but it had worked lose and was dripping ever so slightly (but not enough to pool on the floor). The toilet was only light use anyway, but the seal was obviously weak another to let the odour escape from the soil pipe.

Anyway, the pipe was pushed back in and sealed with mastic or something similar (push fit connection). Seems to have done the trick. It’s probably been coming lose for the last 5 years.

Something to check if you have similar issues. Fortunately it was all quite accessable from under the kitchen sink.