Thermal Barrier for Vaulted Ceilings?

#1

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?

Hammer

#2

YEs, you should expect to see insulation in the cavity.

There are now energy star rated shingles available that can reflect UV from the sun. These are designed for your purpose.

If you dont have adequate insulation up there, no amount of Energy Star is going to help you.

#3

I can’t find any info on the Owens Corning site about UV or Energy Star. What brand/model shingles are UV rated?

Hammer

#4

Anyone have any UV-Energy Star shingle info? Not finding anything helpful on Google…

Hammer

#5

energystar.gov/index.cfm?c=m … rcial#roof

#6

Hi,

The only color that is Energy Star rated is white. GAF’s have the Energy Star rating.

#7

Thanks for the link. Looking at the excel spread there are lots of coatings and metal products, and only a few obscure listings for shingles.

owenscorning.com/around/roof … pListID=12

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.

Hammer

#8

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?

http://img327.imageshack.us/img327/4558/roofdeck01mc8.jpg
http://img327.imageshack.us/img327/9166/roofdeck00nl9.jpg
Hammer

#9

Two inches of fiberglass is about R6. Not even close to sufficient, IMO.

#10

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?

Hammer

#11

Nothing???

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?

Hammer