We moved into a 22yr old house about 6months ago. Since moving in we've noticed various nasty smells in the bathroom, cloakroom, utility and ensuite. They come and go and are not always in all places at once. They mostly occur after a hot dry spell, followed by rain, but not always.
Tonight the smell was very bad in the bathroom while I was bathing the kids. It appeared to come from the toilet, and the waste pipe next to it. This goes into a boxing and then goes downstairs to the cloakroom, and then down to the main sewer. There is a similar setup in the ensuite, which again has the waste pipe going into boxing and downstairs again, to the utility this time.
I have checked in the loft space and the soil pipes do not continue upwards into this space. There appears to be no ventilation of the soil pipes, unless this is inside the boxing, which has no access panels I can look through.
The bathroom tonight had water in the traps on the bath and the sink, and it still smelled, so I don't think the smell is coming from the overflows due to dried out traps. I am also reminded by the boss that the toilet has been recently cleaned!
I can't see any leaks around the soil pipes themselves, so I am a bit confused as to where the smell is actually coming from? Does anyone have any idea? And how do I go about fixing this problem? Some sort of vent pipe?
Thanks for reading. Marc