Recently moved into an older house (1950s built) and noticed that the coat closet has a musty smell.
The coat closet is next to the front door and has one wall that is an exterior wall. It has Tavertine flooring (as does the entry way), plaster walls, and a cheap wood baseboard.
In one of the corners of the closet walls that is on the exterior wall of the house I noticed a gap about a half inch long by a quarter inch wide that went down to the subfloor (I imagine). On the same wall on exterior of the house I noticed that there was a small gap between the cement and the paneling on the outside of the house.
My thought is that when we had pretty heavy rains a few weeks ago that water may have seeped into the subfloor beneath the tile and mildew/mold started to grow. I liberally applied caulk to close the gaps - both in the interior of the coat closet and along the exterior of the house - and have been running a HEPA air filter inside the closet with the door closed for the last 36 hours. However, the musty smell remains.
What is my next step? Should I give the HEPA air filter more time? Do I need a different filter to remove the smell? I presume that if I have eliminated the water source (which remains to be seen) that the mildew/mold causing the smell will die off, will not return, and the musty smell will go with it. Is that understanding correct?