for Cold Climate Housing and much more

Last Updated: , Created: Sunday, January 14th, 2001

Insulating an attic living space.

Rick is complaining that the attic he lives in is too cold in the winter and too hot in the summer.

It is hard to get good insulation, and proper roof space ventilation, when you are trying to keep as much space as possible available for a living space under the roof. The key is to insulate heavily behind the knee walls and in the small horizontal ceiling space, but not to put any insulation in the 3 inch space between the sloped ceiling and the roof. Leave it completely empty to allow for a good flow of air from the soffits to the roof vents at the top. Then put at least 2 to 3, or even 4, inches of foam insulation over the rafters on this section and some drywall over this. This will give a decent amount of insulation without taking away too much head space on the sloped portion of the room, and will allow the ventilation to do its job. 3 inches of foam is a full R-15 over this portion of wall, whereas if you fill the small spaces between the rafters with an R-12 of fiberglass, given the wood structure that is not insulated, you actually have about R-9 of insulation, and no ventilation.

This may not make this space as comfortable as the more heavily insulated rooms below, but now it should be both heatable and coolable (if that is a word).

Keywords: Insulation, Attic

Article 1074