There is a very strong odor, in our bathrooms on second floor of home. House had main floor flood two years ago, and has been completely gutted, sanitized and rebuilt. Odor is only in bathroom. Does not smell like water mold, but a sharp, dry burning type of odor; very unpleasant. Even when not being used, the room has horroble odor, but increases when the shower is used. Is it possible the plastic (older) tub,shower surround is the source? Have tried multiple cleaning products, bleach, vinegar, and nothing helps.

Any ideas? Chris

Take a serious look at vent pipes that might allow vapors to escape into the interior. They won't leak any water, however, they will allow the sewer gas to escape. This can get worse when running water down the drains. Look for a clean out that is not plugged or maybe even a drain without a trap?