I have a 2nd story condo facing the gulf of Mexico. It is July, and the air is very humid. When I go from the condo to the outside, my glasses fog up instantly. Recently, two sheets of sheetrock over the front door (facing the beach), fell. The sheetrock did not have any mold on it. The sheetrock was simply moist and crumbly. Upon inspection, the entire front of my condo's sheetrock (about 3-4 sheets in) are sagging and getting ready to fall. The sheetrock paper is no long strong enough to give the screws holding power. The 5th sheet and further back are fine. No water source is near the front of the condo. The front of the entire building is under a covered deck from above, so rain water leaking through the door is unlikely.
The floor in the unit above mine has soggy floors in the same area; entire front of the building, about 8' inward. We took out the vinyl flooring, and the subfloor underneath is dry rotted in some places. There is dripping water on the bottom side of the subfloor. The top of the subfloor is wet. Again, the subfloor towards the back of the condo is dry.
- There is insulation between the joists, paper side towards the sheetrock. Although I don't think they seal the entire 12" space (2x12 joists).
-We have hosed down the front and side of the building hoping to find water leaking through, but have not seen water penetration from windows or doors.
-Chlorine tested the moisture, and there's no Chlorine, indicating that it didn't come from a city water source.
- Both condo's mine and unit above are air-conditioned for most of the summer.
- The insulation paper is wet and so is the top 1-2" of the insulation facing the subfloor. But the insulation in the middle is relatively dy.
-The best way to describe the area between the subfloor and the sheetrock is a cave that is dripping water from the surfaces.
I'm at a loss in finding the "source". Could this really be condensation? Enough to cause water dripping from the subfloor and forming on the sheetrock surface? What are some ways to test, and prevent this. I plan on taking my sheetrock down and doing something about the space between the joist, if this is the real problem.
Please email with your suggestions. Thanks, Tim