If you would like use just one form of insulation in unvented rafter bays, that you are limited to spray polyurethane foam. A further possibility, not surprisingly, is to develop your roof with structural insulated panels (SIPs).
I don't have a lot of space above or down below the roof composition for insulation / venting. Would a flash / batt unvented assembly get the job done under The one sheathing deck? My insulator has carried out quite a few of such domestically.
2. When you install fiberglass batts, air barriers are far more critical than vapor Regulate. You need a good air barrier on either side within your fiberglass batts.
Population details. Should you be relocating, you don't just treatment regarding how Significantly revenue You'll have to keep the current normal of dwelling: You need to know what it would be like to Reside there.
I now recognize that stucco can't be applied to a roof, so I'll revert towards the a metal roof, but nevertheless want to own an unvented attic. I've study by means of "Making a conditioned attic", and am even now not sure as to The easiest way to progress.
Thanks with the affirmation and information. Considering the fact that all the things is dry this time of yr and the house was lately tented for termites, I will insulate via the beam and seal up the plain air entryways. When I'm able to see within I feel I'll have a better strategy the amount moisture has long been in there through the years.
Great post and dialogue. I have an issue about an current unvented attic assembly. The rafters are 2x4's and the bays amongst them are fully filled with shut mobile spray foam. more helpful hints I would like to increase two 1in layers of polyiso towards the interior of attic then include that has a Visit This Link vapor open membrane to airseal the assembly.
Ensure that you set up insulation that gives at least the minimum code need for ceiling R-benefit. Insulation that exceeds the bare minimum code necessity is better yet.
My perception is the fact if we are worried about air leakage compromising the insulation's effectiveness, vent channels are problematic.
Second, could you make sure you verify this: "If you need to use just one type of insulation in unvented rafter bays, you're limited to spray polyurethane foam."
Though roof ventilation may help dry out damp roof sheathing, it’s vital to limit the circulation of water why not try here vapor escaping from your residence so that the roof sheathing never will get moist to begin with.
You describe your proposed air barrier as "taped felt." I don't Believe asphalt felt is often properly taped, and I do not are convinced asphalt felt can make an excellent air barrier.
If you're building a cathedral ceiling, the greatest air-barrier blunder is to put in tongue-and-groove boards as your end ceiling with no 1st installing taped gypsum drywall. A board ceiling is notoriously leaky, and this type of ceiling is commonly connected to roof sheathing rot.
A vented cathedral ceiling only is smart In the event the geometry within your roof is simple. You'll need a straight shot in the soffits into the ridge. That’s reasonably easy on the gable roof with no dormers or skylights, but If your geometry of one's roof is complicated — with functions like hips, valleys, and dormers — it’s unachievable to assure air movement as a result of all your rafter bays.