how to tell your sewer stack is plugged?
When I bought this house there was a strong musty smell everywhere. During a plumbing upgrade it was found that there was no P-trap on the tub and the standpipe clean-out wasn't properly sealed. (this is a musty old-pipe smell, not a sewage smell). Fixing that has made a huge difference but I still notice that musty smell in the kitchen, as if it is coming from the kitchen sink or dishwasher.
I read somewhere that this could be caused by an obstruction in the vent. Is there a way to check that out without having a plumber or someone come in? I.e. will simply looking down the stack from the roof show things like a wasp nest etc?
Climbing up there will be a bit of a feat for me, so I want to make sure that there is even a point in doing that.