Advice please! This is driving us bonkers.
Our house has a lean-to extension, which houses the downstairs toilet.
Main waste pipe from the bathroom passes down into the lean-to, and then out to the sewers. Downstairs toilet is connected into that. I'm going to assume that the pipe vents into the lean-to roof void, but since there's no access, I'm only guessing.
Problem is the awful sewer smell that we get in the room from time-to-time. No signs of leaking, and smelling the exterior vent into the void (yes, I stood on a ladder and sniffed) seems OK.
I've recently rodded the drains, some way away from the toilet (quite badly blocked). I'm wondering if things have backed up, but can't figure out how (1) toilets would flush OK, and (2), how the smell would come out.
Next step is probably to lift a couple of slates to check how the pipe is finished - hoping there's a one-way valve on there.
Any thoughts, before I post about breaking roof slates?
Cheers
Andy