Why not merely get it done appropriate as well as Make with pressure treated roof sheathing. Even conventional plywood can tackle wetting cycles repeatedly much more than our number 1 super inexpensive OSB.
If it looks as if I'm outside of my depth here... yeah, you guess, I'm. I'm only a homeowner, with only a few days of Online study under my belt. Though the contractor isn't accustomed to this roofing method, so we are being forced to determine it out alongside one another. Value your support immensely.
Circumstance much like Eric, above. If closed mobile foam is sprayed or "cobbled" from xps, do You must fill the whole Area, or only to thickness for preferred R benefit?
Q. "Are you currently saying that rising air flow to that 2nd story attic would really be a foul plan, if we proceed the foam in excess of your entire 2nd story gable roof, and instead we must always make it fully unvented?"
Any house currently being built a lot better than the absolute minimums should really on the extremely least not use OSB for roof sheathing. Imo
First, is it simple to determine irrespective of whether a roof is ventilated? If no soffit vents or facet vents are visible to the roof from the ground, does that necessarily mean the roof is not really ventilated?
Must I handle the flat roof to be a cathedral ceiling and go along with spray foam (or board), fiberglass, and no moisture barrier?
One more problem that will come up in that situation is whether or not that can encourage condensation to the underside with the 1" XPS when it can be cold adequate exterior because the underside on the XPS can be down below the dew stage? Q-three: What to do whenever we re-roof.
We really Really don't know if these roofs have appropriate vent channels, or what type of vent baffles (if any) have been employed to take care of the ventilation gap in between the very best on the fiberglass insulation and also the underside of the roof sheathing.
Inexperienced builders usually consider to meet or exceed these least R-values. Having said that, the code delivers quite a few loopholes making it possible for builders (sometimes) to obtain navigate to these guys away with decreased ceiling R-values than expected inside the prescriptive desk.
The most beneficial Remedy is to address your situation from above, by adding a big degree of rigid foam previously mentioned your existing roof sheathing. It is possible to Create up the layers oneself, of You should buy SIPs or nailbase panels.
You could potentially skip the tape on the best layer of plywood to identical some time and money. That is probably what I would do if I ended up you. Having said that, there isn't a damage in taping the seams of the best layer of plywood.
Just like all types of vent baffles, it’s a smart idea to concentrate to airtight development procedures, particularly if you will end up setting up air-permeable insulation during the rafter bays. Seal the sides of every panel with caulk, and tape the seams amongst panels by using a large-top quality tape. (For anyone who is installing air-permeable insulation like fiberglass, mineral wool, or cellulose, the air flow baffle isn’t optional; it’s expected.
How can this hunt for a approach? Everything you'd modify/include/reorder? Would you agree with taping the seams in equally layers of plywood?