For anyone who is developing a cathedral ceiling, the most important air-barrier blunder is to set up tongue-and-groove boards as your complete ceiling with out initial installing taped gypsum drywall. A board ceiling is notoriously leaky, and this kind of ceiling is commonly affiliated with roof sheathing rot.
But When the installer is conscientious, as well as the rafter bays genuinely are dense-packed, my guess is always that everything will probably be high-quality.
Green builders typically attempt to meet or exceed these minimum R-values. Having said that, the code gives many loopholes making it possible for builders (sometimes) to get absent with lessen ceiling R-values than needed inside the prescriptive desk.
Back on the vent notion. I actually Imagine venting a roof which is airsealed in the inside nicely and created with no vent chutes is probably The easiest way to Make cathedral ceilings.
A further Problem I'm possessing re: Ice & H2o Defend is the fact I had been looking ahead to taking away the recently placed asphalt felt that is certainly presently more than the pine T&G and changing it with a different product, since the asphalt odor with the felt is coming from the T&G ceiling and bothering me (just in the event I necessary any evidence that that ceiling is horribly air permeable...). But then I examine inside the Grace Ice & H2o Defend set up Guidance that "As a result of its slight asphaltic odor, will not utilize Grace... Ice & Drinking water Defend... the place the membrane is subjected to interior living spots." Therefore if I replace the felt with Ice & Water Protect or a similar asphalt-centered product or service, I would possibly just be jumping in the fire to the frying pan, odorwise.
I believe that Invoice Rose is true: these failures involve dampness that is carried by moving air. These are generally not diffusion failures. When the rafter bays definitely are adequately dense-packed -- a large if -- the chance of air motion is very minimal.
My feeling is that the dew point profile would find yourself inside the XPS foam board, therefore a VB must be put on first deck. So as of assembly:
Many thanks all over again with the answers. Now I just will need to uncover an installer With this spot who is familiar with whatever they're executing (so far it has been iffy)!
Re: the air barrier for being placed previously mentioned the pine T&G ceiling and Read Full Report under the foam, would you advocate that we use a little something that is the two an air barrier along with a vapor barrier? Or could it be essential to ensure that the solution we select is not really a vapor barrier, to ensure any humidity that gets in to the roof assembly can dry to The within?
This is an advanced subject, and For anyone who is worried about code needs in your town, then by all indicates you should talk to this problem at your local constructing Workplace. In most cases, renovation do the job is usually executed with out bringing all components of your own home as much as present code needs.
Other than asking you visitors for an evaluation of my approach, I have An additional problem introduced about by concerns expressed by an area builder. He is anxious that once the AC ducts are In the conditioned Area which the ducts might be prone to sweat and may drip all over my home furniture.
to install vent channels among the very best view website of the rigid foam and the highest layer of roof sheathing. I never ever explained that it had been needed
Q. "If I swap the felt with Ice & Drinking water Defend or the same asphalt-dependent item, I'd in all probability just be leaping within the fire in the frying pan, odorwise. That is primary me to imagine that the Solitex or Delta solutions will be greater."
Irrespective of whether you decide to make it vented or unvented, get the details ideal — due to the fact every single cathedral ceiling presents chances for making major issues