Last night actually for my birthday
Instead of family BBQ
Incidentally tried a different take away ( supposedly number 2 on Trip advisor ) and it was very disappointing!!
Back to my normal place next time 15/22 on TripAdvisor!!
It passed all building regs when it was built I still the certs from the buildings inspector..
Looking at other extensions around here all the drain/stack pipes appear to be the same height.
Thanks for your help...
The soil pipe connects to the main sewer outside.
As a feed into the stack pipe is the sink drain and the toilet drain with the air admittance valve about 10” above the toilet connection.
Then a fall of probably 10 feet below ground into the main drain..
I can’t see how pressure can build up...
I had an upstairs extension built 10 years ago, the bathroom sink drain and toilet go down a stack pipe outside.
On top of the stack pipe is an air admittance valve. The valve spring appears ok but very occasionally I notice a sewery smell, the wife never notices it.
Can these valves go...