If you're considering shifting to numerous places or perhaps curious about distinct regions of the nation, you would like to examine multiple metropolitan areas.
The very best approach is to try and do the many get the job done directly: rigid foam earlier mentioned the roof sheathing (as advised within the short article), and fluffy insulation underneath.
It truly is Safe and sound to declare that an present home doesn't have superior roof ventilation if there aren't any soffit vents or ridge vents. It is also Risk-free to say that, even when you can find soffit vents and ridge vents, the roof is not ventilated if it consists of valleys, hips, dormers, or skylights.
Thanks - This is certainly new development, I'm the designer / builder, and the more I evaluate it, I'm liking all rigid - less fussy. The very best layer of rigid around fluffy would make my eave also thick in any case. The air barrier for the T&G ceiling is actually the sandwich of felt and taped three/eight" CDX.
Most of my neighbors below have cathedral ceilings, no attics and Totally no insulation (basically they have got aluzinc roofs on plywood with pine rafters).
You happen to be describing a cathedral ceiling that comes with all attainable issues. There was no awareness to air sealing. The worst achievable insulation was utilised (fiberglass). As well as the roof assembly is unvented. So it really is no surprise you are seeing condensation.
Doug I concur, too many wrongs "overthinking" and overdoing. I after had to resupply a physician constructing an aircraft with dozens of the plane bolts mainly because they ended up tightened to the point of breaking the bolts. Considerably less is more often... Along with the KISS rule.
Many thanks all over again check my reference for your responses. Now I just need to have to find an installer in this place who understands the things they're accomplishing (up to now it's been iffy)!
Set up a layer of closed-cell spray foam versus the underside in the roof sheathing, and Continued fill the rest of the rafter cavity with the air-permeable insulation. All over again, this type of assembly is designed to dry to the inside, Therefore the assembly should never incorporate an interior polyethylene vapor barrier.
Q. "Should I Chunk the bullet and possibility of spray foam insulation, or deliver the builders back up on the roof in December to chop ridge and soffit vents?"
Q. "For an unvented construction without insulation over the sheathing, what about working with wood fibreboard concerning the rafters directly down below As well as in contact with the sheathing?"
I do think you suggest this: Your cathedral ceiling is presently uninsulated. If you find yourself indoors searching up, you are able to see your rafters. Above the rafters you are able to see a layer of boards. Is the fact proper?
If you put in 2x4s (or 2x3s on edge, put in with lengthy screws) perpendicular to your rafters, you might deal with almost all of the thermal bridging issue with no must insert a layer of rigid foam.
Should really i absolutely guidance sheathing seams parallel for the ridge line, for sheathing higher than an air hole? Would not that isolate the air beneath Every single sheet of sheathing, and is always that all right?