So I've been redoing my window sills. Basically I smashed out tile sills and replaced with routered wood sills. There are maybe 15 in the house. I have not had time yet to prime any of them, so for the last 5 months they've been exposed wood.

Recently I noticed a foul smelling odor in my master bedroom. After some investigation I realized it was coming from the wooden window sill closest to my bed. I figured that something died in the wall so I called a pest control guy; he assured me nothing dead is happening and the smell is not decaying animal. He also went under the house to confirm (off grade home).

Thinking that the smell may be coming from outside, last weekend I caulked the sills in the master bedroom to seal the open air between the sill and wall. The smell remains, and seems to be directly on the one wooden sill (but no others).

The best way that I can describe the smell is a sneeze when you have a sinus infection. It smells a bit like death and is musty, and it is playing all hell with my allergies.

I'm thinking about priming the sills tonight to see if that helps, but can anyone tell me what is going on here?

  • 1
    If it comes down to priming, a shellac based primer like Zinsser B-I-N is best at sealing odors.
    – JPhi1618
    Nov 24, 2015 at 15:25

2 Answers 2


you more than likely have mold or some sort of fungus growing in the sill wood. outside of the risks from some species of mold (some can be quite deadly), and the potential for structural issues from rotten wood (walls falling down, etc), the first step is to kill the mold. just spray straight bleach over the whole area. wear a respirator rated for VOC's. let dry and repeat. we normally do it three times to be safe. you will have to open the window for a few hours as the bleach fumes can be strong. once this is done, dig out any punky wood and fill with polyester resin filler (car body filler) to make a hard replacement that is waterproof. then you can continue. you will have to probably touch up the paint around the sill as the bleach can and typically oxidize the nearby paint.

  • I just bleached the heck out of the wood. I'll give it a day to see if that fixed it and then I'll accept your answer if it worked. Thanks!
    – Haney
    Nov 24, 2015 at 20:30
  • 3 rounds of bleach totally wiped out the smell. Thanks!
    – Haney
    Nov 26, 2015 at 16:03
  • the honour is to serve Nov 26, 2015 at 18:24

Since you have isolated it to one particular sill maybe you should simply replace it again. In five months that sill may have gotten wet and activated some fungus that has been latent in the wood. I think replacement is the best piece of mind as well because if you just try to cover up the smell you will always be wary of that fact and be stressed by it.

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