It's Risk-free to mention that an current household does not have excellent roof air flow if there aren't any soffit vents or ridge vents. It is also Secure to say that, although you can find soffit vents and ridge vents, the roof is not ventilated if it involves valleys, hips, dormers, or skylights.
The very best technique is to accomplish all the get the job done at the same time: rigid foam previously mentioned the roof sheathing (as suggested in the write-up), and fluffy insulation beneath.
I made use of to operate being a roofer, and roofs which can be entirely protected with Ice & H2o Shield make me nervous. I see this sort of layout as lazy and perhaps problematic.
What obtained me commenced to the "air limited walls and roof sheathing" was your report of exactly the same identify; specifically South Mountain Company's fantastic post over the Martha's Winery housing development. I noticed Marc's presentation on These homes at BBD likewise.
Bear in mind: if you end up picking to setup rigid foam in addition to your roof sheathing, don’t install ventilation channels under the roof sheathing; these two tactics are incompatible.
Your intend to use 2-inch-thick EPS as your ventilation baffle will do the job. The EPS is relatively vapor-permeable, so it allows a little bit of outward drying. (In almost any situation, for those who Develop a fairly airtight ceiling, there won't be any humidity in this assembly that should escape.)
This post was extremely enlightening and seemed to give a ton of recommendation on cathedral ceilings. But what what my best storm? Your home is thirty decades previous (80's) and im sure the ceiling isn't air restricted. I wish to do one thing this summer/drop to try to repair these leaks but I am fearful that what ever I do wont function and can be a waste site link of money, especially since I havent heard of a solid Answer.
As constructing scientist Invoice Rose has demonstrated, code needs for roof venting have been under no circumstances determined by research or scientific concepts. Inside of a well documented JLC
It is wonderful to incorporate foam board higher than the roof deck Despite the closed cell foam-board (what sort?) on the inside. Roof decks won't be able to dry to the outside via 0.1 for every shingles anyway, significantly due to the fact in zone 5 it can shell out a significant amount of time included in snow/dew/rain with the moisture drive heading inward, not outward.
Thorsten Chlupp is in why not check here the Significantly more challenging weather and he appears to be carrying out wonderful with uncomplicated unfastened fill over the attic flooring....certainly He's employing "ample" amounts (cellulose galore)and he has baffles near the soffit.
I'm dealing with a little bit unique issue which i'd enjoy some input on. I'm creating a Vineyard tasting area within a masonry building (8" monolithic concrete partitions) in 4C/5B local weather zone in So. OR. I have got an exposed 2x10 T&G ceiling about GLB purlins @ 5'oc, so I am making it from The underside up and the last layer to go on would be the sheathing underneath the metallic roofing. I'd prepared to set up an air barrier around the T&G deck (taped felt) then body 2x8 @ 24"oc with significant density batts to fill the cavities, more than which happens to be the sheathing under the metal roofing.
The best way to move forward will be to select a far more vapor-permeable sheathing material -- some thing like fiberboard.
I am building a forensic laboratory made in Massachusetts, and am using a difficult time reconciling relevant building code with my go through with the literature pertaining to insulation and roof deck condensation.
A. I concur. In mild of the odor problem, I do not believe my recommendation to make use of Ice & H2o Defend was a good a single -- so I withdraw it.