"Mold should not be the determining factor in the demolition of a house," says Dr. Stephens, "but it can be a criterion in deciding to gut a house—because if you have mold behind your walls, it's very difficult to get rid of." Simply waiting for flood waters to evaporate is not a viable option, as that could take months or even years, during which mold constantly works its mischief. "If you have a significant amount of mold, as in 60% of your walls being covered with it, we recommend that you actually remove the sheetrock and dry your house out," he says. "It's like a fruit bowl: if you have mold on just one orange, you can throw that one away and keep the rest. But if most of the fruit is covered with mold, it's best to throw it all out."