Said It Here

How to find and handle hidden mold behind walls

Hidden mold behind drywall requires immediate verification and remediation, but sealed walls prevent you from accessing the opening to check the severity. Without knowing the next steps, homeowners panic about safety and air quality while trying to decide whether invasive repairs are truly necessary.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Close the door and leave the exhaust fan on with a towel by the base of the door while sleeping in a different room.
  2. 2
    Choosing to let the issue ride and ignoring it unless moisture visibly presents itself
  3. 3
    Accepting higher heating bills for drafty rooms rather than tearing apart finished spaces

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/HomeMaintenance2 people · September 2026

“I have no clue what the next steps are and quite frankly I’m panicking that we’re breathing in the black mold since we’re sleeping here and this is the only bathroom. I’m a first time homeowner and I need help!”source ↗

Icy_Confidence_9256 · r/HomeMaintenance · 122 upvotes

“Verification is part of the problem because I have no access to the opening.”source ↗

wahoosboy · r/HomeMaintenance · 1 upvotes

“There does appear to be some growth that starts approximately at the knee wall. Is this something that should be remedied even though it will be somewhat invasive or is this something to let ride?”source ↗

wahoosboy · r/HomeMaintenance

Where this came up

People with this problem also raised