We recently discovered what appears to be a small spot of black mold in our son’s bedroom. We live in Michigan, his room faces east with the side wall facing north. Right there in that corner, near the base molding there’s about a 4-5″ spot that is damp. This typically only happens when it gets really cold – as we’ve been experiencing for the last several weeks here in MI. It only appears to be surface mold and can easily be wiped away. Now that my wife pointed it out to me I realize that I’ve seen this spot/mold for the last several years, I just never paid much attention to it because it’s not spreading and doesn’t appear to be damaging anything.
The house is 20 years old and of ‘average’ construction. However this is the only place in the house that has this problem. Again, the carpet doesn’t appear/smell moldy, there’s no stains coming from behind the base woodwork/trim but right above the trim in the corner it’s damp and if you leave it sit long enough there’s a bit of mold forming.
Exterior is siding and I’m sure there’s a plywood sheathing underneath that though I’ve never had any reason to check. Any thoughts on what I can do to correct this?
Thanks, Rob
Replies
Rob,
Mold will only form where there is moisture. Find where the moisture is coming from and the mold will not form. I had a similar case a few years ago in one of our bedrooms. In our case, there was a bad piece of roofing plywood that had rotted through and allowed the roofing shingles to slightly colapse. This collapse formed a pocket for rain to collect. The rain came through the roof shingles, ran down to the wall, went into the insulation which caused the drywall to get moist. Black mold formed on the inside wall over and under the paint. Replacing the plywood and shingles in that area completely solved our problem.
Your problem could be from rain/snow/ice getting under the siding and into the insulation or poor insulation at the corner allowing condensation to form in the drywall. Find where the water is getting in, fix it, and the mold will not come back.
RThomas
here's my bet.
The corner framing can sometimes be hard to insulate properly. You have a cold corner that is sweating in the cold. Hopefully there is not a lot of mold growing in there.
I would drill about a half inch hole directly at 45° intro the corner just above the baseboard. Make up a swab with a coat hanger and cotton to sweep inside and see how bad it is. If totally gross, you might need to tear things apart more.
But for the quick fix, buy a can of spray foam, shake it and spray it into the hole to fill the cold cavity. but put down a newspaper on the floor first and a strip of mashing tape on the top of the base. Leave it there while the stuff boils out and cures. Then cut off the excess and use a dab of caulk to seal over the hole.
The other possibility is that the teen ager is throwing his dirty underwear and bannana peels in that corner all week until just before inspection day...
;)
Excellence is its own reward!
Thanks guys, I'll give this remedy a shot. Should be interesting to see what's going on in there. Since we haven't seen much else in the way of mold/moisture I'm hopeful this will solve the problem.
Thanks, Rob
I have seen it happen because;
1) Too much watering outside.
2) Use of gas stove to heat up the house, or defective gas furnace
3) Water under the house from rain or unhooked sewer.
Ohterwise buy Drying compounds that are made of calcium chloride. What they do is suck moisture out of the air, it does it so well that it will fill up a bucket with water.
You guys are right that there are a lot of other reasons this could be happening. But this description of symptoms is pretty clear. It only happens when it is very cold and it is surface stuffff that wipes off telling me that it is condensing from inside out instead of leaking from outside in..
Excellence is its own reward!