Ultimately, manufacturers started giving stiffer alternatives which have been greater ready to resist the pressures of dense-packed insulation. These goods appear and go, and lots of are no more out there.
I concur with you: I'd choose to see more information on this difficulty. I'm not aware of any failures which have transpired in effectively dense-packed unventilated rafter bays.
Should you’re building a new home, even so, right here’s my guidance: in order to insulate with cellulose, ensure it is a ventilated roof by like ventilation channels under your roof sheathing. Leaving out the air flow channels is dangerous.
Your want to use 2-inch-thick EPS as your air flow baffle will do the job. The EPS is fairly vapor-permeable, so it will allow a little bit of outward drying. (In any situation, in case you Create a reasonably airtight ceiling, there will not be any moisture In this particular assembly that needs to escape.)
Q. "If I switch the felt with Ice & H2o Shield or an identical asphalt-centered solution, I might in all probability just be leaping from the hearth into your frying pan, odorwise. This is certainly foremost me to imagine that the Solitex or Delta merchandise could be superior."
Martin, re: changing the attic about the next Tale bedrooms to a conditioned attic and sealing the soffit vents.... Ahead of this most up-to-date strategy about insulating with rigid foam along with the cathedral ceiling, we were intending to cut a ridge vent in to the gable ridge, so that you can fulfill ventilation code demands. Now We've eave vents plus two pretty useless gable vents, just one on both sides.
In a very term, no — the code explicitly forbids this method. Cellulose can only be used in an unvented roof assembly if there is an adequate layer of rigid foam previously mentioned the roof sheathing or an sufficient layer of shut-mobile spray foam beneath the roof sheathing. Cellulose alone won’t operate.
If I improved my venting element to the web site crafted design and style, among the rafters, as in your lots of blogs on this subject, my air barrier would need to transition again within right before it obtained on the sloped roof; quite cumbersome at the gable partitions. Probably not absolutely sure how I'd do this.
Okay, I used to be figuring that the overall of your rigid foam + cellulose had to be a specific R-price in combination and were pondering working with considerably less rigid foam. I have been reading about unique styles of cellulose. Since I'm putting in from earlier mentioned would a thing like stabilized cellulose do the job because it has my review here slightly h2o additional?
1. Your suggestion is just a slight variation on a element that may be presently reviewed in my weblog, specifically cellulose installed using a vent channel involving the top on the cellulose along with the roof sheathing.
2. I believe your proposed depth might be difficult to Develop. How effortless can it be to harmony within the rafters as you install the membrane, presumably with staples, after which install the 2x2 spacers, presumably with nails or screws, all devoid of Placing a foot between the rafters? I wouldn’t want to make it happen.
For that roof assembly more than the cathedral ceiling, does the stack-up beneath capture all The weather I would need? 2x8 pine T&G (now set up, remains as the finish ceiling)
If you would like a vapor-permeable materials that continues to be an air barrier, pick fiberboard sheathing. But use caulk throughout the perimeter, and tape with the seams, to be sure that the fabric is set up within an airtight manner.
I used to be skeptical of Bill Hulstrunk's declare that AccuVent baffles could endure currently being dense-packed within an enclosed cavity.