When you are creating a cathedral ceiling, the most important air-barrier blunder is to setup tongue-and-groove boards as your end ceiling devoid of first setting up taped gypsum drywall. A board ceiling is notoriously leaky, and this type of ceiling is commonly related to roof sheathing rot.
This post was pretty insightful and seemed to provide a ton of advice on cathedral ceilings. But what what my perfect storm? Your home is thirty decades old (80's) and im guaranteed the ceiling just isn't air restricted. I need to do one thing this summertime/drop to test to fix these leaks but I am fearful that regardless of what I do wont operate and may be considered a waste of cash, In particular considering the fact that I havent heard about a solid Option.
If you decide not to extend the rigid foam about the areas of your roof that have a traditional vented attic, your builder (or an architect) can think of a trim detail that you choose to could possibly live with.
The code restrictions on using air-permeable insulation amongst rafters have been formulated to forestall the roof sheathing from rotting. When fiberglass batts are mounted in unvented rafter bays, the batts allow moist indoor air to get to the chilly roof sheathing.
It seems if one had been to use dense pack cellulose inside a vented cathedral ceiling the vent channel material need to be rigid more than enough to withstand the strain.
If it seems like I'm away from my depth in this article... yeah, you bet, I'm. I'm merely a homeowner, with only a few days of Web research under my belt. But the contractor just isn't accustomed to this roofing procedure, so we're being forced to determine it out with each other. Value your help immensely.
This assembly was not long ago crafted just south of Portland OR. I posted it a few months ago. Right here it truly is yet again (Together with the builders comments) I do think It truly is a reasonably straight forward Make as you get previous the thought of introducing company cavities on your Develop.
Appropriate on! Venting the my link slope safeguards the sheathing from staying caught between two vapor barriers/retarders and offers the h2o a destination to go when There's a leak....a way I will start off applying immediately. Thank you greatly Martin.
Many thanks for your reaction Martin. Would you continue to be happy to implement that unvented approach for just a renovation scenario exactly where There exists non-breathable membrane (eg bitumous 'felt') above reliable board sheathing?
Why not only get it done appropriate in addition build with strain addressed roof sheathing. Even regular plywood can take care of wetting cycles many times greater than our number one Tremendous reasonably priced OSB.
I think that Bill Rose is true: these failures require dampness that is definitely carried by relocating air. These are typically not diffusion failures. Should the rafter bays genuinely are correctly dense-packed -- a major if -- the possibility of air motion is incredibly lower.
The sides in the roof are included with asphalt shingled (GAF Slateline to generally be correct). It looks like I ought to pull down the fiberglass and also have it spray-foamed before I drywall.
Due to their unscientific origins, code demands for venting roofs in many cases are misunderstood. It’s truly worth establishing several standard facts:
We approach to convert to an improperly vented cathedral ceiling to an unvented one particular. Sealing up the soffit vents is actually a no-brainer. What's The obvious way to take care of the ridge vent? Many thanks!