Your caveat is suitable and conservative. With the overwhelming majority of builders, nonetheless, the code specifications will maintain roofs freed from difficulties.
If you'd like to get it done ideal, you need to address air leaks, deal with your recessed can difficulty, and incorporate adequate R-price to at least meet least code needs. It really is loads of work, but it isn't really rocket science. Correcting these complications may very well be high priced, on the other hand.
Considering the lethal pic I truly feel there might be a simple though unorthodox Option. The many rot from heat wet air fulfills chilly wood is correct close to the place a vented hip could have averted all and Devoid of vent chutes.
I've insulated the sides with R-19 fiberglass and now I am pondering: was that a mistake? It's craft paper and I was planning on a plastic sheet in addition, need to I skip that?
If We will set some insulation higher than the ceiling, then I need to put ALL the insulation previously mentioned the ceiling, and avoid the cost and stress of a completely new decreased ceiling. Which means a Make-up of 8", employing XPS. If we Construct up the roof line above the cathedral ceiling of your family members area by 8", we presumably will need to construct up the rest of the adjoining gable roof too.
Martin, Thank you for your reply. Those articles are both really informative. I am getting the feeling that SIPs can be carried out perfectly, but can be beat in selling price with exterior rigid foam programs while you've suggested, with equal or improved effectiveness (with emphasis on air-tightness).
one. It's usually a bad strategy to put in an HRV within an attic. HRVs need to be available adequate to the homeowners to routinely change the filter.
I am undecided in case you are interested within a building science remedy or simply a code reply. From the code viewpoint, this can be a roof that should be insulated to R-forty nine.
The main reason to put the additional insulation in contact with the underside of the roof is the fact that It truly is hard to validate that you've got correctly closed off all vents towards the attic. But when you really do achieve performing that, there must be no problem. By check my source using a blower door is achievable, though tough.
Your program to setup a stack of rigid foam rectangles in Just about every rafter bay is called the "Slice-and-cobble" way of insulation. It's a way usually decided on by homeowners, but in no way picked out by insulation contractors.
As I spelled out inside the report on this website page, You cannot use fluffy (air-permeable) insulation within an unvented roof assembly Until you incorporate rigid foam or spray foam above the fluffy insulation.
Yes, it really is Secure (While before you check with an issue about a particular roof assembly, It will be superior to find out your local weather zone).
Will you be imagining the 'flat' vented cavities will not likely provide the assembly with the exhaust route for humidity?
Q. "The air barrier is to be positioned over the pine T&G ceiling and down below the foam. Would you endorse that we use a little something which happens to be each an air barrier and also a vapor barrier?