So I'm totally confused. I'm finishing my attic, and working on the insulation right now - it's got to be up to code for building inspections.
I've furred out the rafters to accommodate R30, and I know that I have to put in baffles for those sections against the roof to allow air circulation. But the knee walls - evidently they need an air barrier? Tyvek or some other kind of home wrap on the outside, then insulation (R18?), then drywall?
That's fine. So are the baffles.
But do I need to put some kind of air barrier on the roof section, the part that will be covered with R38 at the top?
I'm just a little confused. The air barrier is supposed to stop wind wash, which I understand is moving air destroying the insulating properties of the batts?
So is it just the knee walls that need this air barrier? And why not the ceiling section too? Surely that is equally exposed to the outside air?
I'd like to do this right, first time. As it stands, all I have managed to find, in an afternoon of solid research, is that the knee walls need to be sealed with some kind of air barrier.
Is it just the knee walls though? The sloping parts of the ceiling against the rafters need no air barrier, nor does the flat ceiling? And if not, why not?
Confused...and thinking that I should have got a contractor to do this for me...
I've furred out the rafters to accommodate R30, and I know that I have to put in baffles for those sections against the roof to allow air circulation. But the knee walls - evidently they need an air barrier? Tyvek or some other kind of home wrap on the outside, then insulation (R18?), then drywall?
That's fine. So are the baffles.
But do I need to put some kind of air barrier on the roof section, the part that will be covered with R38 at the top?
I'm just a little confused. The air barrier is supposed to stop wind wash, which I understand is moving air destroying the insulating properties of the batts?
So is it just the knee walls that need this air barrier? And why not the ceiling section too? Surely that is equally exposed to the outside air?
I'd like to do this right, first time. As it stands, all I have managed to find, in an afternoon of solid research, is that the knee walls need to be sealed with some kind of air barrier.
Is it just the knee walls though? The sloping parts of the ceiling against the rafters need no air barrier, nor does the flat ceiling? And if not, why not?
Confused...and thinking that I should have got a contractor to do this for me...