Q. "Considering that I am setting up from over would some thing like stabilized cellulose operate as it has somewhat water extra? I'd personally think about unfastened fill could blow everywhere in the community!"
I thank you for this impeccably timed blog, as I'm at the moment framing my semi-simple cathedral ceiling hip roof (with small ridge). I wish to describe my element and take a look at to know exactly where I am on the right monitor and more importantly, exactly where I will likely have failures. Hope I'm able to amuse a number of you...I experience such as far more I try out to address a priority, the more of a priority it results in being, And that i undoubtedly don't want to get fantastic time, care, and depth to facilitate the demise of my roof.
A lot of the information I operate throughout appears to be within the cellulose business that promises wind-wash is a large trouble with fiberglass; and in the fiberglass industry which asserts which the cellulose team overstates the issue and that on the extent wind-wash occurs it is de facto inconsequential.
BTW, for the foam type, I'm leaning towards XPS for the reason that one) I contain the impression that ISO is considerably fragile, including if it gets in any respect wet, and a couple of) the opportunity of long run outgassing with ISO. Ideally any this sort of outgassing would go upwards and outwards in lieu of downwards into your home interior, but the chance that it would outgas into the inside truly anxieties me.
I wish to correctly insulate my cathedral ceilings and was pondering to spray 2 inches of shut cell foam to sheathing, then fill with dense packed cellulose. I'm questioning if I can attach craft paper and pine paneling for the 2x8 rafters this post after which fill the bays with cellulose.
Correct on! Venting the slope safeguards the sheathing from getting caught between two vapor limitations/retarders and offers the drinking water a destination to go when there is a leak....a method I'll commence working with instantly. Thanks greatly Martin.
As mentioned higher than, we hope to replace the roof this future 12 months. If that is so, at that time I might want to enhance to either an unvented roof or if vital a cold roof (a vented in excess of-roof). (I don;t realize that it matters inside the equations, but we're investigating shopping for and setting up stamped steel shingles.
Power codes build next page minimal R-benefit demands for roofs and ceilings. There are numerous doable code compliance paths; most builders pick the prescriptive route, which sets forth minimum R-values for roofs and ceilings inside a prescriptive desk.
The edges with the roof are coated with asphalt shingled (GAF Slateline to generally be exact). It sounds like I must pull down the fiberglass and also have it spray-foamed right before I drywall.
Ideally, you want to have an airtight barrier previously mentioned and down below your fiberglass batts. If you can achieve Individuals two air limitations, then wind-washing is just not a concern within a roof like yours. (It could be in a very vented unconditioned attic, of course, Specifically near the soffits.)
I have a mansard roof with steep sides with gables, and an almost flat best by using a rubber roof. There aren't any vents, it hasn't been insulated prior to I commenced working on it and also have two thoughts:
As for my energy auditor recommending blowing cellulose in to the mansard sides, you also propose versus that? I used to be beneath the effect blown cellulose helps prevent humidity migration.
Are you imagining the 'flat' vented cavities will not deliver the assembly using an exhaust path for humidity?
Q. "If I execute the unvented roof as developed and put 4 inches of polysio about the roof deck, can I then use open-mobile foam concerning the rafters?"