My house has base floors, and there is a bad sewage smell reaking near one of our bathrooms. I checked for leaks even crawled under the house and nothing. Even checked the P-trap to make sure it was full. The smell comes and goes but is most common around hot weather. 2 plumbers have already inspected and found nothing. A handful didn't even bother to inspect because there was no serious problem. I can't stand the stench anymore. PLEASE HELP!! :(