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Manage My Life

Why is my wall wet?

I've lived in my house for 26 years. From day one, my living room wall has had a moisture problem where the wall meets the ceiling. I've fixed the plaster walls myself three times, and had it done professionally twice, and it keeps coming back. I had a new roof put on my house, and they found nothing bad. The wall that has the problem is a west wall with a outside fireplace chimney. I was told to caulk the chimney. I did and it still got wet, so I paid a roofer $ 250.00 to recaulk the chimney -- it still gets wet. My fire place chimney has 3 flues, 2 are used and 1 is fake. I put caps on the 2 that are used so rain couldn't get down. It still gets wet. I just had 12 inches of insulation put in my attic, they told my that they saw no signs of moisture in the old insulation or on the inside of the roof. The plaster in the living room gets wet on the ceiling and wall in the same place all the time. There is no dripping just wet and soft plaster. I don't know what else to try. Any help would be appreciated.

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Manage My Life
The following are our observations: The problem is not occurring on all four exterior walls. Wind driven rain is primarily from the east. You are experiencing problems on the west wall. The wall in question is the only wall with a chimney and a fireplace. Your inventory suggests that your house was built in the 1950s and therefore it probably has plaster over gypsum lath. Based on these observations, it appears that the problem is related to the fireplace and/or the chimney. You have mentioned caulking the chimney, but you have made no mention of chimney flashings. If flashings are defective, you will likely get leakage in the area that you have described. The chimney flashings are complicated and involve several components. Perhaps your flashings should be inspected by a professional.

Because of the age of your house, we suspect the problem may be related to the plaster and lath. In many houses built in the '50s, there is a small airspace behind the gypsum lath. If you tap on the walls, you should hear a hollow sound. In many of these houses, no airspace was left when the exterior walls became thicker at such places as fireplace flues. The plaster was fastened directly to the masonry. If you tap on the wall in these areas, you will hear no hollow sound.

Water travels through masonry, be it brick or block. The source of this water can be rain, or melting snow against the chimney. If the plaster is attached directly to the masonry, it will act as a wick, pulling the moisture to the inside of your home, where it evaporates, leaving the plaster spongy, flaky and sometimes damp. This diagnosis is via the Internet, and therefore could be dead wrong, however we suggest that you tap on the walls to see if you can tell the difference between the walls in front of the chimney and elsewhere in the house. If our theory is correct, the solution involves strapping the wall, and refinishing it with an airspace behind.
by Manage My Life
April 26th, 2007
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