I have a couple questions regarding how to best insulate a cabin roof. This is a vacation cabin in snow country, a mile high in the Sierra Nevada. Its a simple box with a 12:12 pitched gable roof. The roofing is metal over skip sheathing. Its occupied on average every third weekend year round and for a couple of weeks in the summer.

The second story is all above the first floor plate so the wall/ceiling is the underside of the roof rafters until the 8′ line where the ceiling flattens out and is attached to the bottom of the collar ties (or celing joists I guess). The flat part of the ceiling is currently insulated, but the area between the roof sheating and the angled walls are not. There are no vents between the roof rafters. The only attic venting is via screened openings in the gable walls near the ridge.

I’m trying to figure out how to insulate the area between the roof sheathing and the interior angled walls. I could probably slide rolled insulation down between the rafters but I don’t know if that would cause a moisture problem since there are no rafter vents. I could probably install rafter vents from the outside, but there is no way to install insulation dams above the vents. If I’m using roll insulation, I suppose I could anchor the insulation such that is stays a foot or so away from the vents.

So my questions are;

Do I need to worry about installing rafter vents? Its pretty dry up there, even in the winter.

Am I on the right track with shoving roll insulation between the rafters? I really don’t want to do blown-in insulation and I don’t have a way to install dams above the vents.

Am I worring about nothing? We only use the gas heater to initially warm the place up, other than that we heat with wood. Once I retire I expect we’ll be up there a lot more and even at our current usage we use a lot of wood which is why I’ve been thinking about insultaing the entire roof.

Thanks, Mike