Preferably, you ought to have an airtight barrier above and under your fiberglass batts. If you can realize These two air limitations, then wind-washing isn't a problem in a roof like yours. (It can be inside a vented unconditioned attic, not surprisingly, especially close to the soffits.)
Code won't look to use because it's grandfathered in. It seems like I have to redo the corridor ceiling.
Q. "You say 'You don't need an inside vapor barrier,' but Additionally you claim that 'You will need a fantastic air barrier on each side of one's fiberglass batts.' The latter would turn into an inside vapor barrier not so?"
By Martin Holladay
I thanks for this impeccably timed web site, as I'm at present framing my semi-fundamental cathedral ceiling hip roof (with shorter ridge). I wish to describe my element and check out to know wherever I'm on the correct keep track of and even more importantly, in which I may have failures. Hope I am able to amuse a few of you...I sense such as extra I test to deal with a priority, the greater of a priority it gets, and I absolutely don't desire to choose terrific time, care, and detail to aid the demise of my roof.
Q. "If I execute the unvented roof as built and set 4 inches of polysio over the roof deck, am i able to then use open up-cell foam between the rafters?"
I've a matter for blueskin, as a both equally an air and vapour barrier, but also it'll act as a seal for that screws that hold all the things down. In reference on the vaulted schematics on this site, it demonstrates vapour/air barrier on top of insulation, which acquired me wondering. As good as I am putting in materials, nobody is perfect, and an air leak may possibly create among XPS seams. The moment ANY dampness receives all visite site the way down to reduced sheathing, it really is sport more than.
First, can it be straightforward to discover no matter if a roof is ventilated? If no soffit vents or aspect vents are seen to the roof from the ground, does that mean the roof just isn't ventilated?
But Should the installer is conscientious, as well as rafter bays actually are dense-packed, my guess is the fact that anything will be great.
Other than asking you viewers for an assessment of my approach, I have A further concern brought about by issues expressed by a neighborhood builder. He is concerned that when the AC ducts are Within the conditioned House the ducts will likely be prone to sweat and will drip throughout my home furnishings.
You don't make clear no matter find if This can be new building or perhaps the renovation of the current creating. I alternatively suspect It's really a renovation -- or else one particular may believe the designer from the building would even have offered a style and design on your roof.
Doug... For a few explanation I did't see your article #17. Looks like two of us at the least think there could possibly be a super easy reasonably priced Remedy.
A. This can be a gray space within the developing code. It is really Secure to express that no business insulation contractor would use that method, which Lots of individuals get in touch with "Lower and cobble.
The prepare: Component A: I discovered 1" Dow rigid foam backed five/8CDX for a similar value as the bare CDX, And that i intend to double it up similar to a SIP, putting in The underside sheet foam aspect up and the subsequent sheet on prime (staggered needless to say) with the foam dealing with down, giving me two" of insulation among the plywood.