I obtained a disaster of the household which was partially remodeled, It is in Zone 16 (a California designation much like IRC zones). It's a six/twelve vaulted ceiling above the residing/kitchen area area. The roof is held up by two lengthy beams that run four ft out parallel into the ridge , Therefore there's no straight air path a how approximately the peak ridge beam.
If you want to create a ventilated insulated sloped roof assembly, decide on a form of air flow baffle that can be installed in an airtight fashion. Web page-constructed baffles are very best.
I live in northern Vermont, and I haven't got ample encounter with air con to answer your dilemma about condensation on inside ducts.
We really Will not know if these roofs have right vent channels, or what sort of vent baffles (if any) had been utilised to keep up the ventilation gap involving the highest in the fiberglass insulation plus the underside on the roof sheathing.
Since I have stated the right way to make it happen, I may also Permit you to understand that Lots of individuals have completed Everything you propose.
Rafters are 2x4, 12/twelve slope, and the roof is complicated with intersecting ridge traces, valleys and dormers. (The home originally had a cedar roof. The deck is the normal spaced fir planks.) Resulting from the construction, there is nearly no probability of getting enough air consumption by way of soffit vents. (Along with the structure problems, you will discover problems due to the fact the many spaces in between rafters where by they meet up with the very best plate were being bricked in, seemingly at time of development). Good standard circulation-by underdeck roof ventilation will be tough. Whenever we 1st looked into this job, the setting up inspector requested us to continue to use vent channels (low-cost polystrene was Okay) to seize no matter what ventilation we could.
Can we (does the code make it possible for it)? Does it make practical perception? Are there pitfalls as a result of our local climate? How could possibly We have now to switch that to fit it to out scenario?
Put in rigid foam insulation above the roof sheathing and air-permeable insulation in between the rafters. Such a assembly is designed to dry to the inside, so the assembly should hardly ever include an interior polyethylene vapor barrier. If you select this process, it’s probable (while not essential) to install vent channels involving the highest of the rigid foam and the best layer of roof sheathing by putting in a series of parallel 2x4s — 1 above Each and every rafter — extending from soffit to ridge. (For more information on this strategy, see How to Install Rigid Foam On Top of Roof Sheathing.)
"Once you have installed the code-mandated thickness of rigid foam previously mentioned your roof sheathing, you’re no cost to install just as much fluffy things as you want among the rafters."
Joe Lstiburek: "A vented attic, the place insulation is put on an air-sealed attic flooring, is one of the most underappreciated making assemblies that We've got while in the record of developing science."
Thanks all over again. The roofer agrees that 2x4 framing to lift the peak about the vented attic will be a workable Resolution to match up the roof strains.
I've constructed log houses while in the Yukon Territory in northern Canada for 30 several years. Most log structures have cathedral ceilings. The majority of the roofs We now have created are as follows (from The underside up): log purloins, nominal two" (2x6) t&g decking, 6mil poly, one one/2" extruded polystyrene foam, 2x10 rafters on 24" centers, 7" fiberglass, 2x4 strapping, 7/16 OSB, underlayment (fifteen lb paper, 30lb felt, or now we would even use ice and water protect). There can be about an inch of air Room down below the strapping for each vertical and horizontal air movement. All roofs are vented with strip vents for the eaves and vents inside the soffit (2x6 t&g) at the peak at both finishes. I would disagree that venting is not necessary should you quit the airflow on the warm side, for 2 explanations. To start with it is actually quite challenging to stop all airflow, especially with standard classic procedures (ie chimney and plumbing vent penetrations through the roof) We have a number of tactics produced over time to seal the vb on the eaves and gables, but there remain nail penetrations through the vb. Overall I do think we had incredibly limited seals but one could never ever next say airtight.
Like most mansard roofs, your roof is unvented. Your mansard roof has various sections -- the steep sections in the perimeter, and also the low-slope part in the center. These sections need to be insulated in the same way, mainly because all these roof assemblies are unvented.
Insulated cathedral ceilings are a comparatively recent phenomenon. The fad for insulated cathedral ceilings (and excellent rooms) definitely took off from the 1970s and eighties, when illustrations commenced popping up like mushrooms after a heat rain.