Old roof is coming off (three layers of shingles). Roof deck is 3/4in x 7in planks with 1/4in spacing. Not planning on overlaying the deck with plywood.
Half the house has normal attic space with blown-in insulation, the other half has vaulted ceilings. In the summer heat just seems to radiate right through the vaulted ceilings into the home.
I have not torn off any shingles in the vaulted area yet to see what’s between the deck and the interior rock. Should I expect to see insulation?
Is there any kind of thermal barrier that could go down under the shingles? Is one layer of shingles going to allow even more heat to pass through than the three that was up there?
I had Sierra Gray as my selection, but after seeing the samples thought it was too light so I changed to Quarry Gray. Now I’m wondering if I should change back to Sierra.
Got the three layers torn off today. New shingles go on Tomorrow. What I found in the vaulted area was about 5 inches of space between the roof deck and the sheetrock. There is fiberglass insulation that is less than 2inches thick inside the space.
Is it normal to have 2inches of insulation and 3inches of space between the deck and the sheetrock?
Is it worth the cost to rip up half my roof deck and put in better insulation? Would I recoup the cost in energy saving? Would I notice the difference?
Is it ok to simply blow-in insulation and fill up the rest of the 5in gap? There basically is no venting for this style of roof/ceiling right? I see holes down low under the eves, but up top there’s no outlet(s). Is any air gap needed for venting?
