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Community and Q&A

With respect to exterior masonry chimneys, how do you insulate them to improve the overall thermal building envelope?

David W. Bearg | Posted in Energy Efficiency and Durability on

Without a fire going, the poorly insulating brick will suck heat out of the house, and when there is a fire going, insulation will allow more of this heat to flow into the house as opposed to merely heating the outdoors.

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  1. 69tbird9 | | #1

    If you install a Chimney Balloon that will at least air seal the fireplace chimney low by the firebox. This eliminates the damper leekage which is usually the path of least resistance when the fireplace is not being used.

    I have seen the doghouse masonry chimneys that have been sided over with the vinyl siding with the insulation permanantly attached to it (Fullback), but that was only as a retrofit and I have a feeling that was a siding contractor that just didnt know any better. It didnt go above the roofline, but I am sure that stuff is not heat rated.

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