Last summer I got a call to do leak repair on a copper roof I did not install. 5 out of 6 chimneys were showing moisture (plaster bubbling and discoloration), but no actual dripping water. The flashings were not tall enough and there were no crickets on 6′ wide chimneys. We added crickets and reflashed. Went thru the winter and everything appeared to be dried out. Plaster guys started repair last week and signs of moisture have reappeared. The owners like to keep the temp about 68 in the summer and its been incredibly humid the last couple of weeks. The moisture is apparently getting drawn from the flues thru to the inside. My first suggestion is chimney top dampers. Anybody else got any idea?
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What runs in these chimneys? Furnace gas or fireplaces - unused now? are there clay flue liners or just parged brick interiors?
I ask because I see this a lot with old chimneys that have no liners, and more in ones that have had furnace or boile5rs added to them. Especially with high efficiency newest combustion units. They fire up long enough to make mositure to condense but not loing enough to warm up the chimney mass. Old lime mortar is even worse at letting the water migrate through it. Some of these have no dampers either so house air is always venting the moisture up through the cool condensing surface oif the chimney interior.
It's frustracting to get call after call to fix a "leak" that isn't.
So it there is no liner, they need to call Golden Flue or rebuild, IMO
One way to prove it to them is to wrap the top of the chimney and then let them see the beaded water on the inside of the plastic the next AM.
Further the experiment by then taping plastic across the fireplace openning to stop room air from going up. A couple days later, there will be less moisture on the plastic wrap above.
But be sure no combustion units tap into the chimney elsewhere in the house or the CO2 will put your customers out of your misery.
" no crickets on 6' wide chimneys"
?????That really made my eyebrows perk up high. What else did they do wrong on this place?
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