I live in a house built in 1955. While remodeling a closet, I found a single moldy jack stud, right next to a non-moldy king stud. The mold itself seems to be dry. I was able to cut a little bit off from the wood and below the surface the wood seems stable, no soft spots or similar.

This is an inside wall which connects two bedrooms, with no water lines running anywhere close. Above this is the attic (with no water leak) and below is a crawl space that has a sump pump which is also working.

When opening the closet prior to demolition, I always smelled something musty/earthy. Due to the location of the stud I only have access to one side. I have read other posts related to mold on this side and have seen the recommendation to use 3% Hydrogen peroxide.

I have multiple questions regarding my issue:

  1. Would treatment of only one side of the stud have any chance of success?
  2. Given that this is an old house and the mold hasn't spread to other studs or the wall, is it safe to say that this mold is "inactive"/not actively spreading?
  3. The wood is different in this stud than in any of the other ones. Could the mold have been there originally, for example because the wood was moist?
  4. Would the best remediation be to replace this stud?

My ultimate goal is to get rid of the smell and don't have mold spores in the air.

Mold on jack stud

Mold not on top

  • 2
    Did you test it for mold? Are you sure it is not dirt/stain? Mold usually wants damp, dead air, lack of light. Odd for it to be only on one stud. Spraying some bleach on it stops mold. Mold spores are in the air anyway to some extant.
    – crip659
    Dec 29, 2023 at 19:29
  • That's a good point, I am not sure. I will test it for mold next. I suspect that the wood might have been "infected" prior to installation as it looks different than the other studs.
    – Freddy
    Dec 29, 2023 at 20:21
  • 1
    Not all studs in a house had a pampered life.
    – crip659
    Dec 29, 2023 at 20:42
  • If you're 100% sure that this isn't due to water getting on the wood, encapsulation is likely to be your best path forward unless you want to tear things apart enough to fully replace the board.
    – KMJ
    Dec 29, 2023 at 21:34

1 Answer 1


I treated the stud with bleach (a mold removal product) and later with hydrogen peroxide after it was dry. I repeated the process twice for good measure. I also exposed it completely to the subfloor and it wasn't moldy from the bottom, luckily. Here's an after picture.

treated stud

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