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Community and Q&A

Addressing mold after roof leak

KristinVT | Posted in General Questions on

A roof leak around my chimney caused a foul-smelling mold issue in my roof last summer. Because the house has a cathedral ceiling, there’s no attic or other cold space under the roof. So, to clear out the mold-damaged insulation and treat the mold-damaged wood, we’ll need to take the roof off. (This turns out to be okay as we have been wanting to replace and better insulate the roof anyway.) The question my contractor and I are struggling with is how to best treat the wood while the roof is off. We can’t simply pull all the wood out as it doubles as the ceiling of the house. I haven’t been able to find any mold remediation companies that will work on top of a roof. Would appreciate any recommendations for companies and for strategies!

To specify, the mold is not black mold, and the issue is not cleaning up the appearance of the wood. The problem with the mold is its strong odor. 

(And yes, the wood inside needs treating as well, but we have some leads on how to do that, and we can do that job at a separate time from the roof replacement.)

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  1. Expert Member
    BILL WICHERS | | #1

    I had almost this exact same problem a fear years ago except that we found the mold after a new roof was put on, so we worked from inside (which was ok, we were putting a new ceiling up anyway). The remediation company sandblasted the mold off the wood first, then treated with a spray (you can buy mold treatments online). For small areas, bleach solutions are commonly used, and sometimes hydrogen peroxide. I used hydrogen peroxide before we spray foamed and a month after the remediation crew finished just to be extra sure there was no living mold left.

    Note that sandblasting off the mold makes a lot of fine particles so you need the proper safety equipment to do that safely.


  2. KristinVT | | #2

    Thanks for this info, Bill. What remediation company did you use? I haven't found one yet that will do roof work.

    1. Expert Member
      BILL WICHERS | | #3

      A local place here in SE Michigan. If you’re in this area, I can look up the name. They worked from inside though, so they didn’t have to do anything on the roof accept to repair a few places they poked through (which they subbed to a roofer).


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