Install a layer of closed-mobile spray foam from the underside of your roof sheathing, and fill the rest of the rafter cavity by having an air-permeable insulation. All over again, such a assembly is designed to dry to the inside, Therefore the assembly must never involve an interior polyethylene vapor barrier.
I question that the condensation is occurring against the chilly ridge beam. Relatively, I feel it is probably going that condensation is going on around the underside within your ridge shingles or perhaps the underside in the asphalt felt underlayment.
I am a homeowner in Seattle. Have a freshly-framed, vented cathedral ceiling to insulate. Straight bays, 2x12, 24" o/c. The existing approach is to employ batts of some variety while in the bays, get treatment to air seal the interior surface area, steer clear of penetrations, air seal the vent channel too (bays totally sealed), double prime The within floor for vapor resistance. I have a couple questions on baffling the vent channel: one. Some of the setting up pros I am working with really feel the jury is still out on baffles and are recommending leaving the batts open to your channel except close to the vents, assuming the 1-two" air channel could be preserved.
The code constraints on the usage of air-permeable insulation between rafters had been created to circumvent the roof sheathing from rotting. When fiberglass batts are mounted in unvented rafter bays, the batts allow for moist indoor air to get to the cold roof sheathing.
A brand new standalone direct vent fuel stove is going in within the far end of your area underneath the metallic box. I figure if we use XPS board, it would need to be pulled back again several inches from about that place, but I failed to Imagine it will avoid me from making use of XPS totally. Seems like Roxul is much less of an issue in terms of heat/fireplace.
Martin, Thanks for your reply. Those articles are both quite instructive. I am receiving the sense that SIPs can be done nicely, but is usually defeat in cost with exterior rigid foam programs when you've advisable, with equal or far better overall performance (with emphasis on air-tightness).
Although roof air flow may also help dry out moist roof sheathing, it’s vital to Restrict the move of h2o vapor escaping with the property so that the roof sheathing by no means will get moist to start with.
Suitable on! Venting the slope guards the sheathing from becoming caught between two vapor barriers/retarders and offers the h2o a destination to go when There exists a leak....a technique I'll begin employing immediately. Thank you very much Martin.
When they had been venting the dryer within (code violation?) and also have an connected greenhouse I wager the partitions are moldy much too. Get started from the laundry area with its perfect moisture level supply "dryer".
"R-19 batts are certainly air permeable, and on extensive unobstructed rafter bays you have got very a stack effect. It does not have a enormous level of air leakage to deliver some drying there. Also, Should the batts are unfaced or kraft-faced, the drying toward the interior will be considerable.
It sounds like an excellent prepare. Determined by what type of rigid foam you choose, you may a knockout post end up getting insulation while in the array of R-sixteen to R-24. Even though that's fewer than code necessities, it's Substantially, significantly better than what you may have now.
I see the advice is usually that when starting off with board sheathing, one really should spot a watertight membrane in excess of the sheathing in advance of installing the lowest layer of froth. Having said that, in my case the roofer has already done positioning new felt around the T&G board ceiling/roof deck. Can that felt substitute for the prescribed watertight membrane, below in San Jose/Climate Zone 3?
I ordered a disaster of a property which was partly remodeled, It is really in Zone 16 (a California designation comparable to IRC zones). It's a six/12 vaulted ceiling around the residing/kitchen area spot. The roof is held up by two lengthy beams that run four toes out parallel to the ridge , thus there is not any straight air path a just how approximately the peak ridge beam.
Hello John - This task was in Vermont within a ten-yr aged residence and as the caption signifies, the principle culprit was leaky can lights from the cathedral ceiling. But the situation was exacerbated by an attached greenhouse, which communicated with the remainder of the residence, and also a clothes dryer vented for the indoors over the Winter season.