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derek_d77
how to insulate over plaster directly on brick?

I have a 100 year old twin that has plaster walls directly on brick.(no studs or fir strips)the rooms are small i would prefer not to lose much floor space.i am considering putting 2x4 on the flats and using spay foam or a normal framed wall with fiberglass. I don't want to mess with the exterior since i love the brick. Should i be worried about moisture? Should i let it be? Should i just sheetrock over top? Any thoughts or ideas?

Timothy Miller
Re: how to insulate over plaster directly on brick?

Howdy. small rooms framing them out1.5" then Spraying lock tight foam to the North and West walls is a good idea but the foam is $$$. This type of foam seals so no moisture issues.
If framing and installing fiberglass consider a wider top and bottom plate and staggering the studs so no direct contact with the brick then horizontal weaving the fiberglass. This therm o break from the wall will keep you home much warmer.

Depending on where you live i would consider making the south wall a passive solar heating wall. Wold install a glass wall outside of it making it a Trombe wall. leaving the interior brick exposed. Several books in library show this and or a small sun room attached you may want to review some. Thsee walls supply upto 60% of heat needs by the home.

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