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Gotsta maintain air flow, moo-y importante.

'Spose it rains one day. I don't know if it rains in Georgia but just for the sake of argument let's say it does.
The moisture in the air goes way up and the roof gets kinda moist. inside and out. Hey it could happen.
If you don't have enough air flow that moisture inside the attic next to the roof won't dry fast enough and you could be lookin at mold or worse, wood rot.

Insulation don't do squat when you gots big holes in the roof.

Quote:

Originally Posted by rfuerst911sc (Post 8443451)

My intention was never to block off the soffit. If I extend the foil all the way to the top plate it would create a 2 ' wide trough ( rafters 2 ' on center ). This trough would start at the soffit and continue up to the ridge vent. But you gave me an idea. The rafters are made of 2 x 4's and where the horizontal and vertical boards meet is a perfect place to line up the foil. It would leave an air gap at the bottom. Once the sheet rock is in place as you suggest a piece of R19 fiberglass insulation could be slid into place. This would allow air to pass through and would block the blown in insulation from sliding down into the soffit area. A win-win. Probably 90-95 % of the hot air will flow up the trough between the roof deck and the foil. What little spills out through " the gap " will also flow out the ridge vent. Plus it gives the gap at the bottom that the vendor suggests. And it will save me tons of specialty cuts in the foil. Sure I would love spray foam but then the soffit vent would be covered and I don't want to do that. And I can do the foil and blown in insulation for much less than the foam. And have much higher R value. Being in the South I am more concerned with heat penetration vs. heat escape but with the foil and insulation I believe I will have both covered.

I get ya now. You're leaving a air gap that will allow air to travel between the foil and the roof sheathing. The main thing you have to be careful of with the ventilation is making sure you have enough. If you don't you can actually bake your roofing shingles from the inside out. You don't notice it happening until your shingles start curling.

Quote:

Originally Posted by rfuerst911sc (Post 8443986)

I'm curious why you started at the top ? I don't think there is a right or wrong place to start just curious. If we are going to be totally anal ( maybe we shouldn't be ) it would seem to me that starting at the bottom and overlapping the seams on the outside of the previous row offers the least path for leakage. I'm probably over thinking this x1000 ! :D

No real reason, it was just easier that way. The attic spaces either had a small door or pull down stairs that led to about the middle of their areas instead of one of the far ends. It's easier to make sure you're installing the strip straight when you have more room to move around though, instead of lying on your back on some ceiling joists in a tight area.

The reflective foil is a done deal. How ironic I find a guy selling 1750 s.f. of the stuff on local Craigslist. Said he way over bought. He was asking 150.00 for both rolls I offered a 100.00 and both rolls are now in my basement :D. I don't need anywhere near this much for the garage but for the price I'll use what is left over for the house ! Score !!!;)