I used a home mold test kit (leftover from my previous question) to see if I had mold in my basement (where I sleep). Turns out a little bit of mold is growing in the petri dish. The mold looks to be greenish in color, almost a green-white. It also looks a bit fuzzy. I looked around and cannot find any source of it, so I figured I would clean all of the wood beams, insulation, and walls as well as run a dehumidifier and air purifier (with HEPA filter) to get rid of and prevent the mold. The biggest issue is that there is one part of the ceiling that is drywalled, and a part that isnt (the main cable line as well as water lines needed to be accessible)

I was considering just spraying some vinegar behind the drywalled section because I cannot reach behind there to scrub, nor can I see all that well to target specific sections should I see mold. I figured the vinegar would kill the mold even without scrubbing, and the dehumidifier would prevent the spores (which apparently cannot "die"?) from spawning new colonies.

Is this an effective plan? Or will the vinegar add moisture to the drywall/wood studs and actually feed the mold? Is there a more effective way to treat the mold and prevent it in the room?

PS: the room as only a small basement window and cannot be opened, so air flow is poor, so I am trying to avoid bleach/ammonia. Plus I heard they cannot penetrate porous surfaces anyway

  • You need to keep the moisture in the air down or nothing you do to kill mold will be effective. On the other side, if there is low humidity, mold will not grow, even if there are mold spores. I suggest you focus on lowering humidity rather than disinfecting.
    – Yehuda_NYC
    Commented Aug 20, 2018 at 23:58
  • @Yehuda_NYC I have a dehumidifier running non-stop now, which should lower it down. I believe it is currently at 50, not sure what the minimum this dehumidifier can get is. Is this sufficient to kill the mold or should I still proceed with the disinfecting
    – ChrisM
    Commented Aug 21, 2018 at 0:54
  • 50% is well within the recommended range. I doubt you will smell any dampness at 50%. Also, mold will dry up (but be there to spring back to life if it gets more humid).
    – Yehuda_NYC
    Commented Aug 31, 2018 at 14:00

1 Answer 1


Although Vinigar is a weak acid it can kill surface mold. I would recommend hydrogen peroxide at 3% it is more effective at killing mold and bacteria and doesn't stink after application. I would also spray the exposed wood surfaces, when lumber is milled it is sprayed with a biocide that doesn't last long and I have seen older units start to grow mushrooms in just a few months. And ply wood is worse when the sheets of veneer are cut mushrooms begin growing in days. Most spores are killed in the hot press process. Keeping the basement dry with a dehumidifier will be the best plan forward without moisture it cannot grow. But make sure to treat the exposed wood because you sleeping in that area create a large amount of exhaled moisture that may be enough to activate the mold.

  • Thank you for your response! Is it safe to just spray the hydrogen peroxide on the wood and let it air dry? And what about in the areas I cannot see/reach? Can I just blindly spray the wood beams (it will certainly land on the back of the drywall as well) to be safe, or will this spur more mold in those dark and hidden areas? The dehumidifier should be pulling air from them as well, but Im not sure how the added moisture would affect things
    – ChrisM
    Commented Aug 21, 2018 at 20:23
  • It is safe to use a 3% solution, I learned this some 20 years ago when working in a hospital. They used that solution to reduce its infection rates without the harsh smell of other cleaners. I have been using this since then, this solution is stronger than the store brand of peroxide I purchase a quart at a time from a local chemical supply and add the peroxide to water to get the 3%. Don't spill the concentrated peroxide on carpet as it will take the color out quickly and you should wear gloves I have used on untreated wood to kill black mold with great success. I hope this helps.
    – Ed Beal
    Commented Aug 22, 2018 at 15:55

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