Why do you get an intermittent smell of sulfur- damp starting in upstairs bathroom spreading across landing and down into hallthe house is 4 years oldthe smell doesn't eminate from toiletsinkshower?

Answer 1

Swer gases can back up in any drain that has a dry trap, one that is not often used. Make sure water is run into drains at least once a month. It is also possible that you have a disconnected sewer vent pipe hidden in your walls. This would allow the sewer gas to enter your living space air. Some modern buildings have been built in a great hurry. Some Plumbing fittings, mainly PVC fittings, have not been glued and can come apart.