I'm helping some freinds with their home. The issue is they have an unfinished basement and they have some dirt odors that come up through the floor. they also get some minor flooding every yr. too. some yahoo put a vapor barrier directly onto the dirt floor...which does nothing when it floods. I'm going to get a couple large rolls of poly and staple it to the floor joists in their basement. i will then tape the seams with duct tape. this should be sufficient and a cheap fix to help eliminate the earthy odors and moisture that makes it's way through the floor into the house. one thing that i was wondering......is there something that i can spread on the unfinished dirt floor to help cut down on the odors?? if so......i would greatly appreciate any advice. thankyou.