Insulated cathedral ceilings are a comparatively current phenomenon. The fad for insulated cathedral ceilings (and excellent rooms) definitely took off inside the nineteen seventies and eighties, when illustrations started showing up like mushrooms after a heat rain.
My residence built-in 63 below in Ohio contains a cathedral ceiling without any ventilation. Actually there quite a few cross-supports operating perpendicular to the key joists and other framing things that will make this unfeasible. So I want to make it a highly effective unvented roof. Half of your roof has 2x8 joists and the opposite 50 % has 2x12s. At the moment There's a membrane covering (rubber) which is worked very well for over twenty years but is showing indications of deterioration and may possibly require replacing shortly. Obtaining performed transforming on the inside and going for walks within the roof I are aware that lots of the sheeting must be replaced combined with the very little insulation which is there now. We've had condensation troubles previously so I now there are air infiltration and bridging challenges.
I ordered a disaster of the home which was partly remodeled, It is really in Zone 16 (a California designation comparable to IRC zones). It has a 6/twelve vaulted ceiling more than the residing/kitchen place. The roof is held up by two lengthy beams that operate 4 toes out parallel into the ridge , Consequently there isn't a straight air path a how up to the peak ridge beam.
You do not need to make use of insect monitor, due to the fact fiberglass batts should be enclosed by an air barrier on either side. When the prime facet of fiberglass batts are subject to wind-washing, the going air degrades the effectiveness in the insulation.
I now know that stucco can not be placed on a roof, so I will revert to the a steel roof, but still want to get an unvented attic. I've examine by "Making a conditioned attic", and am nevertheless unsure as to The ultimate way to carry on.
You happen to be proposing a vented roof assembly. To get a vented over here roof assembly, the code won't demand that any foam insulation be placed in direct contact with your roof sheathing More Bonuses -- Quite the opposite.
You're not the sole individual using this issue. For many who (such as you) are concerned about The difficulty, There's two options:
Will it sound right to spray and Reduce and cobble 4 inch closed mobile foam/board on underside of sheathing followed by fiberglass Within the bays and one inch of eps/iso underneath the rafter (to prevent thermal bridging) prior to finishing with drywall? Will I create a vapor sandwich and improved leave the ultimate EPS and take the thermal bridging?
If the air inside of my property was humid unconditioned air, I could well be equally worried. But will not likely The within air be somewhat dry mainly because of the on-heading air con? Really should I be concerned out condensation forming on my AC ducts if I cathedralize my ceiling?
In order to try a halfway solution that might or might not function, you are able to eliminate several of the drywall near the ridge, and put in spray foam insulation within the underside of the roof sheathing, just in the region near the ridge beam.
If you end up picking to set up open up-cell spray foam in lieu of closed-mobile spray foam, your roof assembly will be able to dry considerably to the inside. Just Be certain that the spray foam layer is thick adequate to keep your rafter bays previously mentioned the dew issue through the winter.
I've an unfinished attic, with cathedral ceiling, no insulation presently. in five-10years we will be incorporating dormers, but in the meantime i would like to insert insulation and drywall in The best, most reversible/salvageable manner. My approach is to hang two levels of two inch polyiso underneath the rafters, taped with staggered seams leaving the rafters empty, so basically a vented assembly. I have extra blocking to the floor joists and could make the polyiso constant in the knee partitions. I believed I'd personally add furring strips along with the insulation then cling drywall, thinking that the furring strips would produce an airgap, allowing for the foil to act as a radiant barrier.
Very well the roof is occurring with the main layer of insulation (on-leading the purlins, underneath the roof sheeting). There appears to generally be adequate space left inside the four" purlin cavity for the 2nd layer of R11 to get put sites in without any modification.
"When you have mounted the code-mandated thickness of rigid foam above your roof sheathing, you’re free to set up just as much fluffy things as you need between the rafters."