Well, this is not making me feel good about this situation. The thing is, there's no evidence of dampness anywhere. When we moved into the house 5 years ago, there was obvious water damage to the wall and inside the front hall closet, and a neighbor told me there was a flood 2 owners previous (so that could be anywhere from 7 years or older). When contractors redid our upstairs bathroom there was rotting wood around the toilet, all since replaced. However, we have never seen signs of dampness or mold growth. Mold testing is just something my wife and I wanted to get done because we knew of previous water damage. Now I don't know what to do. We've contacted our plumber about doing leak testing, and he didn't seem helpful.