The primary vent baffles to strike the market — the vintage Proper-Vent of your 1970s and ’80s — ended up economical, flimsy products fabricated from skinny polystyrene. Polystyrene baffles have numerous drawbacks: currently being skinny and versatile, they will’t resist the pressures from dense-packed cellulose or blown-in fiberglass; they don’t ventilate the complete width from the rafter bay; and as normally installed, they allow air to leak out the very best of your insulated assembly.
On an unrelated subject: The Chilly Local climate Housing Study Heart has developed a video clip (beneath) exhibiting one approach to making an insulated cathedral ceiling. The tactic proven within the online video is especially suitable for builders in climates topic to ice dams.
Q. "I'm wondering if I should furr out the rafters for getting the desired thickness of spray foam, or if installing a couple of inches of polyiso foam to the underside on the rafters, once the spray foam, could get the job done?"
You will be proposing a vented roof assembly. To get a vented roof assembly, the code does not demand that any foam insulation be placed in immediate contact with your roof sheathing -- Quite the opposite.
I've presently insulated the steep sides of my unvented mansard roof with 6" fiberglass (and I had it inspected), would you endorse I rip that out and use spray or board foam? I've gotten conflicting information on regardless of whether to deal with it for a wall or maybe a roof.
Ideal on! Venting the slope shields the sheathing from becoming caught between two vapor obstacles/retarders and gives the drinking water a spot to go when There's a leak....a way I will start off making use of immediately. Thanks a This Site great deal Martin.
Set up a layer of closed-cell spray foam against the underside in the roof sheathing, and fill the rest of the rafter cavity with the air-permeable insulation. Yet again, this type of assembly is intended to dry to the interior, Hence the assembly should really by no means consist of an interior polyethylene vapor barrier.
(d) There might be adequate air leakage at the "soffit" and ridge to supply air move that acts the best way a air flow hole ordinarily would.
The reason to put the additional insulation in contact with the underside on the roof is that it's tough to confirm that you've efficiently closed off all vents for the attic. But when you truly do succeed in carrying out that, there really should be his comment is here no issue. Having a blower door is possible, even though tough.
Your plan to install a stack of rigid foam rectangles in Just about every rafter bay is called the "Slice-and-cobble" approach to insulation. It can be a technique normally decided on by homeowners, but under no circumstances selected by insulation contractors.
I am together with a photograph of the solution: spray foam held down from the major edge of the rafters making sure that air might be drawn up from soffit vents to gable vents from the truncated attic cavity.
And so the question is: seal the stucco vents and include the spray foam roof and Don't be concerned about condensation? You can find hardly any low-hanging fruit within our variety of design, especially on existing properties, Which is the reason consumers are remaining sucked into the spray foam roof fraud.
Your weblogs on this subject have already been really beneficial And that i enjoy your suggestions. ( I do examine right before I submit questions : )
Relating to installation: Although it has been efficiently set up in Europe for a few years, we have just gotten the material, and so we sit up for finding it with a position site soon and actually installing it - and of course, reporting again how it went.