Hi,

I hope you can help! I recently moved into a 90 year old home in Los Angeles. It was bank-owned so no information was given. I had contractors come in and renovate some things but they told me there was nothing wrong with the plumbing. Which the inspector also said.

However, in the hot weather I started to notice a horrible smell coming from the light switch inside the medicine cabinet. There was quite a big gap around the light switch where you could see the cavity of the wall . I had my contractor come back to see what he had to say. He got up on the roof and checked that there was indeed a vent pipe. Then he crawled under the house to check the plumbing there. Nothing was found.

I re-did the P-trap and filled the gap in the wall with that spray foam that hardens. Everything seemed to be OK. But over the past week we've had 100+ degree weather and the smell has started to return but in the bedroom (which shares a wall with the bathroom) It's the same wall that I filled with foam.


If you put your nose right up to the wall you get a nostril full of the smell (sewege/general funk!)

Any suggestions would be GREATLY appreciated!

Thanks in advance!

The vent may be plugged, or broken... gentle use of a snake from the roof will indicate which... Given the age of the structure, care should be taken...