How to insulate between rafters and keep them exposed?

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Last updated on January 1, 1970


Jake Schloegel, CR, President and Founder

We have an old house, pre-1800’s. We live in MA. We have a room above our kitchen that is equivalent to an attic I guess you could say. The room currently has no heat, has two windows, and is adjacent to a finished room that is heated. No insulation between the lower kitchen or adjacent room. The rafters are exposed. Between the rafters there is plaster (horsehair maybe) directly attached to the roof planking beyond that there is a layer of plywood and new shingles. My question can I insulate between the rafters and keep them exposed. Also, there is crawl space on either side of the eaves. One eave opens to the wall space below (outside air) the other leads to wall space below but heated as that side of the house had an addition added that is open to kitchen and heated. I am hoping to add something thin directly to the plaster to help keep the room warm and maybe add heat or trap the heat rising from the kitchen. Any advice appreciated! Thanks


Massachusetts gets pretty cold and requires a fair amount of insulation in the roof, since that is where most of the heat from your house escapes.  In the Midwest, we are required to install a R-38, or about 11” of batt insulation in the attic.  With that kind of depth requirement, I don’t see how you could keep the rafters exposed after installing the proper R-value of insulation.  I have seen wood strips added to the existing rafters, to increase the depth of the rafters, which allows for thicker insulation and keeping the rafters exposed.  There are foam type of insulation products, is one, that can be sprayed on and require less depth.  I would suggest you have a professional insulation company visit your home and see what they suggest.  With the age of your home, I don’t think it would be a good idea to compromise on the insulation.  You don’t want to be cold in your new room.

Good luck.