A. Kevin Powell responds: The answer may depend on the perceptions of your customers. While it's a fact that mold will not grow once the materials dry out, you might want to consider other factors: Are the homeowners sensitive to the mold issue? Does your site get frequent visits from prospective customers? Is the moldy lumber being used where it might be rewetted, like an exterior wall in a bathroom?
If so, it might be a good idea either to not install the moldy lumber, or to clean any installed framing that has molded before close-in.
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