I have an old roof that has leaked after a big rain storm this week. I will definitely need to replace the roof, but I am wondering if I need to do something about the water that has already leaked into the walls to prevent mold damage.

The leak is visible inside the house where the ceiling meets the wall. Also, one of the windows frame in the wall has developed a large crack next to the frame and water was leaking in from the crack when it was raining. (photos attached).

Would the water in the wall dry by itself over time without mold damage if I replace the roof ( and therefore fix the source of the leak )? Or, would the amount of water that has already leaked into the wall be an emergency and I need to immediately take out the drywall to dry the wall?

Also, would I wait to dry the wall after replacing the roof, which may take 1-2 weeks, or is it an emergency and I need to dry the inside of the wall now?

I unfortunately have a cathedral ceiling and don't have the skills to go into the tight spaces into the attic to check for extent of water damage. Because of general corona virus concerns, The roofing companies I've contacted refuses to come into the house to look at the leak, but only wants to give me quotes for roof replacement. I'm concerned though that roof replacement won't dry the existing wall.

water spot where wall meets cathedral ceiling

crack formed next to window frame where water leaks out

close up of crack that formed next to window frame where leaks out

  • that doesn't look like enough water to cause mold problems. My area had 4.65" of rain in the last week, so there's a lot of worst-case scenarios coming into bloom, but it's not like that happens often enough to keep your wall saturated.
    – dandavis
    Commented Jun 5, 2020 at 18:55

1 Answer 1


Mold is unlikely from a one-time water infiltration event. That is, unless the inside environment is exceptionally damp and prevents the water from drying out.

Generally mold happens when there is a long term issue with water or moisture.

  • I agree a 1 time event is not usually two big of a deal. I suggest poking some holes at that water mark it will allow water to drain if any more rain and not go down the wall. I might also put a fan blowing on that wall to help it dry out inside, yes inside, your walls breathe and blowing air helps to get the moisture out of the insulation.
    – Ed Beal
    Commented Jun 5, 2020 at 19:00

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