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Tue 6 Sep, 2011 09:48 am
We have a two story high atrium in our house about 12 feet on each side of the base and about 20+ feet tall with 3 skylights. Three of the walls (upper opart) face into the attic, one wall is an interior wall with no attic. Last year, black mold began to grow on the interior wall near the top. Cleaned mold, primed with oil primer, painted with satin latex paint with anti-mold additive. Also added exhaust fan triggered by a humidistat set at 53% and thermostat set at 80F. Problems began after installing new roof shingles. Inspections revealed no leaks.
Now we notice droplets forming on the upper part of the interior wall, in the same area where the mold was. They are yellowish and seem viscous and they leave a kind of discolored trail. No mold, yet. Problem occurs in hot, humid weather. There were no problems for 14 years prior to this. Could the new roof somehow be responsible?
Would appreciate any ideas.
Vic
This interior wall . . . what's behind it? Is it just the wall studs and insulation?
Try putting a wall vent at the top and the bottom of the wall, or several vents.
I think the wall is not being allowed to "breathe'.
I know of a church that had the same problem with its walls. The moisture in the studs was absorbed by the warm drywall and forming mold in straight lines up and down. The vents seemed to help.
@PUNKEY,
Thank you for your ideas. The interior wall in question is between the atrium, where the problem is, and a loft. There is no insulation in this wall. I have added a power vent near the top of the wall.
I just consulted with Sherwin Williams and their tech representative suspects that the paint was applied during warm and humid conditions. These circumstances lead to the situation I have observed--ie some of the additives leech to the surface of the paint in time. The recommended solution is to wash the wall until the symptomsw stop.
We'll see.
I'd like to hear more details about how you cleaned up the mold before painting again. For instance, did you use bleach? Did you allow the wall to dry thoroughly for several days before painting again?
Also, are the wall studs wood or metal? If metal, has anyone checked to see if condensation is forming on them inside the wall?
In the meantime, this
article may provide some clues as to what is going on.
Here's an excerpt:
Quote:Prepare before you paint
Proper preparation. That’s the key to successfully keeping mold and mildew from invading a freshly painted surface, stresses Jeff Spillane, senior marketing manager for Benjamin Moore.
“One of the biggest mistakes painters make is power-washing a house and thinking that just because they don’t see any mildew that it’s been blown away. It’s like mowing a lawn that’s filled with dandelions. When the grass is first cut, it looks great. But a week later, all the dandelions are back,” he says.
“The key to a successful paint job is to prepare the surface and remove and kill the mildew. You need to coat the surface with bleach and then power wash or scrub it off. If you paint a house with mildew spores present, you’ll embed the spores into the film and the mildew will be hard to get rid of, if not impossible,” Spillane says.
Many industry experts agree that a 3:1 mixture of water and bleach will kill existing mildew. However, recent Sherwin-Williams literature claims bleach can control mold growth on surfaces but often doesn’t affect the source of the problem. It goes on to say that bleach shouldn’t be used on porous materials or metal.
@Butrflynet,
Thank you for your post. I washed the wall with 3:1 bleach solution, scrubbing thoroughly. Allowed to dry for several days, primed with oil primer, and then painted.
Thanks for all your help/input on this! I just wanted to get the best approach before I sealed off the walls, and I developed some idea.
@exaramco,
Condensation can be a problem in both winter and summer. A most common condition contributing to household condensation problems is very high humidity levels in the air within the home. In the summer, the humidity range may be higher because of the higher outdoor humidity levels we sometimes experience then.
We can considerably reduce condensation by producing less moisture and keeping our home well ventilated. Always using lids for saucepans and not leaving items boiling for longer than needed and keep the internal kitchen door closed and window open slightly when cooking.Open the window straight after bathing, in order to get rid of the moisture. Keep all rooms ventilated by slightly opening windows and keeping doors shut, particularly when the room is in use. This helps release any moisture and prevent it spreading around your home. Don’t block air bricks or window vents.
Well now a days with waterproofing method being available, problems like these can be avoided from at the time of construction itself. Other than that the method used in this post is also effective to recover from such situations.
Hi, need help on condensation problem in 15 yo home, painted wall in a dinette, after a few extreme hot days I started seeing many tiny blisters on the wall, there us no leak, I do use central air condition, maybe IRS caused by the wall outside hot temperature and inside cool? Or while I was away foe a few days the temp inside as up to 90 degree? .
What do I do now before it starts to get mold?
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