I live in Mass./New England, so it gets pretty cold. I have an old farmhouse
with three chimneys---two are unused. I would like to cap the unused
chimneys with something to help reduce heat loss---and to prevent critters
from getting in.
Any suggestions on products and solutions?
Affix a piece of wood or something about 4 inches down and fill with cement,
or go get some galvanized sheetmetal from Home Depot (in the duct section)
and form it around the top of the chimney and tape it on.
Whatever you do, make sure it has a slight peak to allow water to drain off.
If there is even a slight chance you may use it again, you don't want to
dump cement in your flue. A simpler solution is a metal block-off over all
inactive flues. I'd recommend against using galvanized metal. Galvanized
will eventually rust, which will discolor the sides of your chimney by the
time you notice it. Not very attractive. Working with stainless will cost
more up front, but it will be a more long-lasting solution.
Don't use tape or something that can fail and send a large, sharp piece of
metal sailing off your chimney. That could cause major property damage or
possibly kill someone. Silicone will create a good seal, and you can
easily cut the block-off loose if you decide to utilize the flue in the
future. For added security, you can use tapcons to secure the corners to
As always, you should be absolutely sure a flue is inactive before sealing
it off. Selecting the wrong flue could lead to CO poisoning, etc.
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