Unless one makes use of Excessive treatment with The nice and cozy side air barrier which consists of figuring out that all fastener penetrations are sealed as well it is best to presume some air stream. The installation referred to listed here With all the ice and h2o defend beneath the shingles clearly built a better air barrier than whichever was on the warm aspect.
As outlined by part R806.3 of your 2006 Global Household Code (IRC), “At least a 1-inch space shall be offered between the insulation and also the roof sheathing and at the location in the vent.†This kind of vent Area can be made by setting up 1 inch by 1 inch “sticks†in the higher corners of each rafter bay, followed by stiff cardboard, skinny plywood, OSB, fiberboard sheathing, or panels of rigid foam insulation.
Most rafters aren’t deep sufficient to support the insulation necessary to meet minimal R-values necessary by code, particularly when the rafter bays consist of a ventilation channel.
If you wish to use rigid foam, the top destination to put it's along with your roof sheathing, not below your roof sheathing.
Martin, many thanks. I just talked towards the roofer and he rejected the thought of only Placing the foam around the household room cathedral ceiling. That Strange "jog" in the roofline, having it quickly bump up 4" or eight" where by the family home begins, in the course of the back again facet of your roof, would defeat the thought of a continual slope for rain to come back down when it hits the upper Component of that back again roof. And so the four" or eight" peak addition desires to carry on through the total second Tale roof line.
2. Everytime you install fiberglass batts, air limitations are much more important than vapor Handle. You need a superior air barrier on each side of the fiberglass batts.
Back again for the vent plan. I really Imagine venting a roof that may be airsealed in the interior perfectly and developed with no vent chutes is quite possibly The easiest method to build cathedral ceilings.
I don't have a great deal of home previously mentioned or down below the roof structure for insulation / venting. Would a flash / batt unvented assembly get the job done less than The one sheathing deck? My insulator has accomplished Plenty of of those domestically.
When they were being venting the dryer inside (code violation?) and possess an attached greenhouse I bet the walls are moldy also. Commence inside the laundry special info place with its best dampness stage source "dryer".
Are you presently imagining the 'flat' vented cavities won't provide the assembly by having an exhaust route for moisture?
That looks really pleasing: select R-thirty around the underside with the deck at our dwelling making use of a mix of fiberglass batts and XPS as I explained above, and afterwards add an extra R-10 (2" XPS) on the very best side when we tear down and re-roof? However that looks like it's way too uncomplicated.
Q. "You say 'You don't want an inside vapor barrier,' but You furthermore may say that 'You will need a good air barrier on each side of the fiberglass batts.' The latter would change into an interior vapor barrier not so?"
I made use of to work to be click a roofer, and roofs that happen to be totally covered with Ice & Water Protect make me anxious. I see such a design as lazy and perhaps problematic.
A lot of people creating vented cathedral ceilings use the interior drywall as their ceiling air barrier. Web Site The regular way to create the transition in between the outside wall air barrier and the inside ceiling air barrier is to set up a large piece of plywood in addition to the wall's best plate.