Plumbing

Can't find where smell is coming from - can i silicone the area?

Anonymous user 16/03/2024 - 2.31 PM

So i've had a lingering smell in a my extension for a couple of years where the soil pipe runs. The extension was built 30 years ago over an old manhole/inspection chamber and haven't had an issue with slow draining or anything, just a lingering smell as i say. Finally got it checked out and the inspection chamber was pretty clogged with filth etc. and there was quite a bit of sitting/stagnant water too so I got it jetted and cleared and everything is running fine (got a camera up there too & all seems broadly ok), but the smell remains a couple of weeks after it's been cleared - seems to even permeate the grout in certain areas. So i'm meant to be moving out of this house in a couple of months so was really keen to get the smell resolved for the incoming owners. The lingering smell is around the area where they have concreted over the old inspection hatch and we've never had an issue with mould or anything like that in the time we've been here so i was just wondering what the implications of putting silicone around the area to "seal in" the smell so to speak? I'm not sure what else to do as i've had a couple of drain guys look at it and each is fairly non committal as to what they think it is and ripping up the concrete extension floor (tiles, underfloor heating etc. etc.), i think would be a massive undertaking and ultimately might come to nothing. Each has said similar in that "if i were you and was moving in a couple of months i'd just do X,Y, Z" but i'm not very comfortable with that I was just looking for advice and whether the silicone approach would just be asking for trouble. I feel like my 2 options at the moment are try mask or block the smell somehow or rip apart part of my house and spend a fortune on investigation - i was just hoping there might be some sort of middle ground! Many thanks for any replies PS. many thanks for the replies. I should have been clearer in my original post that the old inspection hatch is no longer accessible - it has a 150mm concrete block on top now and has also been tiled over for good measure and a new inspection hatch was put in the garden instead back when the extension was built but the smell seems to be coming through the gaps in the wall or through the tile/grout.