Posted by Tom Cox on June 30, 19100 at 09:39:06:
I have an old building that is occasionally filled with a sewer odor. The odor appears first in an area of the building that contains no fixtures except a couple of floor drains. I put water in the drains to make sure the traps were filled. The building has been remodelled so many times that anything is possible. Is there a visible "smoke" that can be introduced into the drains to help locate the leak?