The most effective Answer is to deal with the problem from earlier mentioned, by including a substantial degree of rigid foam higher than your existing roof sheathing. You may Construct up the levels on your own, of you can buy SIPs or nailbase panels.
We've made a decision to insulate on the exterior from the roof sheathing many of the way across both sides in the gable roof, in an effort to match up the roof strains.
It feels like you might have an current roof with tile roofing. I'm guessing that you are writing from Europe. It looks like the insulation is made up of "tight-fitting wood fibre board" concerning your rafters -- thickness and R-value aren't specified.
If you wish to build an unvented insulated roof assembly, you almost certainly don't desire to disturb the tile roofing. That means that one of the most appropriate insulation could be spray polyurethane foam. Naturally, the present insulation need to be eliminated prior to you put in the spray foam.
Positive It is really a great deal of issues. It appears like much less trouble the detail posted as case in point while in the blog higher than and makes use of no foam... Which is a "biggie" for me.
The key reason why To place the additional insulation in connection with the underside of your roof is always that It can be hard to validate that you've successfully closed off all vents for the attic. But when you truly do reach undertaking that, there needs to be no trouble. Having a blower door can be done, though tricky.
Doug I agree, important link a lot of wrongs "overthinking" and overdoing. I after had to resupply a physician constructing an aircraft with dozens of the aircraft bolts as they have been tightened to the point of breaking the bolts. Considerably less is a lot more from time to time... Together with the KISS rule.
I'm not a enthusiast of full peel-and-stick roofs, for various causes. But your approach will most likely be good. Just Make certain that your roof sheathing is dry around the day you put in spray polyurethane foam -- since the sheathing won't be drying a great deal in possibly path just after It can be encapsulated concerning peel-and-stick membrane and spray foam.
Need to I exploit airtight baffles or not, I do not see a method to have moisture escaping in the assembly with airtight baffles, fiberglass and xps on the inside, regardless of the the dew level might be inside this assembly and possibly build condensation that cannot evaporate without the need of ventilation.
So the issue is: seal the stucco vents and include the spray foam roof and Don't be concerned about condensation? You can find little or no minimal-hanging fruit inside our form of construction, Particularly on current houses, Which explains why individuals are becoming sucked into the spray foam roof scam.
The air leakage that Dana pointed out would keep the roof dry, but would undermine its thermal performance.
I appear to remember this but, it has been awhile. Appears to be there are lots of selections for best site us in this article. Many thanks for all your aid plus the refresher. Once again I celebrate the practical dissemination of knowledge With this technical age vs looking for just a ebook.
This assembly was a short while ago constructed just south of Portland OR. I posted it a number of weeks in the past. Right here it's once more (Along with the builders reviews) I do think It really is a reasonably simple Establish as soon as you get past the concept of adding service cavities to the Make.
At some point, companies began providing stiffer choices which can be improved in a position to resist the pressures of dense-packed insulation. These products and solutions come and go, and plenty of are now not out there.