Published on April 15th, 2013 | by Henri0
Mold on the ceiling
Q. I have mold on my bedroom ceiling. A contractor friend thinks he found the problem and can correct it.
When the mold is removed with Clorox bleach and water, should a coat of something be put over it before painting? If so, what?
A. I hope your contractor friend can correct the problem permanently. There is no need to apply anything prior to painting but if the repair is not permanent, mold is likely to recur. You didn’t say where the mold is on the ceiling but I suspect it is at the joint of the ceiling and the exterior walls. If this is the case, it may be that the attic insulation doesn’t cover the top plates of the exterior walls, which causes these areas to be cold. Condensation results and mold is not far behind.
Your friend should make sure that there is insulation all the way to the outside edge of the top plates but without blocking any eaves vents. If the mold is only on the walls with eaves, it may be caused by water backing up behind ice dams and wetting the insulation. Poor air circulation and excessive dampness in the bedroom may also be the cause.
Once the problem is taken care of, you may want to consider painting the bedroom ceiling with Zinsser’s Perma-White; it is guaranteed to resist mold and mildew for five years, but will not work if the cause of the mold is not removed.by