mold on brick wall

Old 10-09-05, 11:48 AM
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mold on brick wall

I have a 6 by 8 brick wall in my basement that has a free standing wood stove. The wall is on an exterior wall in the basement, and it is directly below a fireplace from the middle floor. We moved into our house last December and in March I noticed black spots in the brick wall in the basement. The brick is rather porous, and where there are little holes in the brick is where the black spots appear with a round patch of grey around the black hole, about the size of a dime. Not every brick has the black spots, and the spots are showing up even on the one layer of bricks on the floor that extend out from the wall about 3 feet (the wood stove rests on the brick floor). The mold is also not showing up in the mortar, but only on the brick.
Ive had a mold expert come out and confirm that it is mold, although there is no evidence of mold anywhere else in the finished part of the basement or unfinished work room. I have applied straight bleach to the wall and used a wire brush to scrub the mold off, and the spots diminish slightly, but do not go away. The flues for both the wood stove and the chimney have been inspected, and there are no cracks in either. I am concerned where this mold is coming from, and how to get rid of it. The people who have looked at my wall said that they have never seen anything like it before. Ive had someone suggest that the bricks had mold to begin with, although the brick fireplace in the floor above does not have this problem. The basement now has a dehumidifier in it, to keep the mold from spreading. Has anyone experience a similar problem? Any suggestions? Thanks!
Old 10-09-05, 12:16 PM
Join Date: Mar 2005
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mold on brick wall

The mold experts I have worked with say that the bleach will kill mold, but not the spores. When the spores become wet they can become mold.

If your mold expert says it is mold, then I would have to believe him.

You must have some source of moisture and it appears it is absorbed from the floor or wall at the base. Another source of moisture would be down through and around the chimney for the fireplace above. Without knowing the configuration it could enter the house anywhere.

A suggestion - after you clean your brick with bleach, and let it dry and then apply a clear masonry sealer to cut off the source of moisture and hopefully this would stop the appearance.

Good luck


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