I've a mansard roof with steep sides with gables, and an almost flat prime that has a rubber roof. There aren't any vents, it has never been insulated just before I begun engaged on it and have two concerns:
If you would like make an unvented insulated roof assembly, you've two choices: (a) You can add rigid foam to the exterior aspect of one's roof sheathing, followed by a second layer of roof sheathing and new roofing, or (b) You may insulate the underside of your respective roof sheathing with spray polyurethane foam.
As for my energy auditor recommending blowing cellulose in the mansard sides, In addition, you advocate against that? I had been beneath the effect blown cellulose stops humidity migration.
If you wish to make an unvented insulated roof assembly, you almost certainly don't want to disturb the tile roofing. Meaning that quite possibly the most suitable insulation could well be spray polyurethane foam. Not surprisingly, the present insulation really should be eliminated ahead of you install the spray foam.
1. Remove the can lights and toss them absent. Recessed can lights must never be set up within an insulated cathedral ceiling.
Exactly what does an average person with my work title make in A further city or list of cities? Is this occupation stagnating in All those locations, or is there massive progress in those sorts of Positions in recent years?
an air barrier. If you want to install EnGard insulation batts in an unvented cathedral ceiling, You will need to obtain a big layer of rigid foam insulation previously mentioned the roof sheathing.
Many thanks once more for your answers. Now I just will need to seek out an installer Within this space who is familiar with the things they're performing (so far it's been iffy)!
Why not just get it done appropriate additionally build with stress taken care of roof sheathing. Even regular plywood can tackle wetting cycles repeatedly over our number one Tremendous low-cost OSB.
You're proposing an unusual means of insulating your roof. If I have an understanding of you appropriately, you want to install EPS concerning the tops within your roof trusses and also your roof sheathing.
Martin, many thanks. I just talked for the roofer and he turned down the idea of only putting the foam about the relatives place cathedral ceiling. That weird "jog" from the roofline, owning it abruptly bump up 4" or eight" the place the family place starts off, in the middle of the back side of the roof, would defeat the idea of a ongoing slope for rain to come back down when it hits the higher Component of that again roof. Therefore the four" or eight" top addition needs to continue through the whole 2nd story roof line.
I seem to remember this but, it has been awhile. Appears to be there are many options for us listed here. Many thanks for all your support as well as the refresher. Again I celebrate the handy dissemination of knowledge In this particular specialized age vs looking for the book.
This assembly was not too long ago created just south of Portland OR. I posted it a couple of months back. Right here it is yet again (With all the builders reviews) I feel it's a reasonably simple Construct as soon as you get past the thought of adding company cavities to the build.
If you need to set up a combination of shut-cell spray-foam within the underside with the roof sheathing and air-permeable insulation in between your rafters — an technique occasionally named “flash and batt†— the creating code demands that spray foam (or, arguably, rigid foam insulation) be “used in direct connection with click to investigate the underside on the structural roof sheathing†and that the foam insulation satisfy the necessities read what he said “specified in Desk R806.