Positive the instance shown is for the reduced pitch (not flat) roof. But adjust it to the pitched roof fewer than 6-twelve and the small print remain a good method (I believe).
If you'd like to create an unvented insulated roof assembly, you've two choices: (a) You'll be able to increase rigid foam to the outside side within your roof sheathing, followed by a next layer of roof sheathing and new roofing, or (b) You could insulate the underside of the roof sheathing with spray polyurethane foam.
Your strategy to install a stack of rigid foam rectangles in Each individual rafter bay is called the "Lower-and-cobble" method of insulation. It can be a technique frequently decided on by homeowners, but in no way picked out by insulation contractors.
The most beneficial approach is to complete the many get the job done at the same time: rigid foam higher than the roof sheathing (as suggested inside the post), and fluffy insulation underneath.
It can be fantastic to add foam board over the roof deck Despite having the closed cell foam-board (what form?) on the interior. Roof decks won't be able to dry to the exterior via 0.one for each shingles in any case, specially due to the fact in zone five it will expend a substantial amount of time protected in snow/dew/rain with the humidity push heading inward, not outward.
Put in rigid foam insulation over the roof sheathing and air-permeable insulation concerning the rafters. This type of assembly is made to dry to the inside, so the assembly must in no way include things like an inside polyethylene vapor barrier. If you select this technique, it’s feasible (although not necessary) to setup vent channels concerning the top from the rigid foam and the best layer of roof sheathing by installing a number of parallel 2x4s — a person higher than Every single rafter — extending from soffit to ridge. (To find out more on this strategy, see How to put in Rigid Foam Along with Roof Sheathing.)
The particular style and design revealed was for a Passive Dwelling. The roof thickness & use of a services cavity could possibly look like overkill for the majority of projects, but If you would like an airtight lid, a support cavity can get you there - permanently... And allow you to wire and light the interior.
In the word, no — the code explicitly forbids this method. Cellulose can only be Utilized in an unvented roof assembly if there is an sufficient layer of rigid foam earlier mentioned the roof sheathing or an suitable layer of shut-cell spray foam beneath the roof sheathing. Cellulose by yourself gained’t get the job done.
I believe you'll want to article a sketch. I can't visualize what you are speaking about out of your description. If you need to install an HRV with your attic, why do you might want to install a watertight stucco roof above some sort of EPS box? Is just not your attic previously dry? Most attics have roofs.
In the ultimate summary it reads: "If you're making use of fluffy insulation, you will need two air obstacles: a person down below the insulation, and a person earlier mentioned the insulation.
You wrote, "the rafters remain uncovered," but I am undecided Whatever you indicate by that. Do you might have kraft-confronted batts in between the rafters, Using the kraft experiencing still visible?
Your intend to use 2-inch-thick EPS as your ventilation baffle will do the job. The EPS is fairly vapor-permeable, so it enables a little bit of outward drying. (In almost any situation, when you Establish a reasonably airtight ceiling, there won't be any see humidity Within this assembly that should escape.)
A completely new standalone direct vent gasoline stove goes in with the far conclusion in the home beneath the metal box. I figure if we use XPS board, it would need to be pulled back a number of inches from around that place, but I did not Believe it will prevent me from employing XPS entirely. Seems like Roxul is a lot less of a concern with regards to warmth/hearth.
Whenever they were venting the dryer within (code violation?) read the article and have an attached greenhouse I bet the walls are moldy also. Commence during the laundry space with its ideal dampness issue resource "dryer".