So you're going to rip off all the roof sheathing and replace it with foil-faced OSB? I'm not sure that's a cost-effective measure if your existing roof sheathing is in good condition. And while a radiant barrier is required in new construction, I don't think it would be required for a simple reroof.
What's the SRI of the shingle you've selected? I expect the energy code does place a lower bound on that for a reroof.
Cheers, Wayne
this is a 1962 house. with all the glory of 1962 technology.
1x6 stringers, with cedar shakes over 15# paper.
comp put over that, without it being removed. a recover,
which is no longer allowed, but it was then. the second roof is old.
amazingly, there are no leaks.
we are removing two layers of roofing. leaving the 1x6 stringers.
then, a layer of OSB with foil on the bottom side.
then, glace fire and ice. twirly whirly vents in three places.
then, comp shingles, matching most of the rest of the neighborhood.
the foil backed OSB is the same cost as bare OSB, according to my roofer.
that is to say, there is no upcharge to me for it. he's already charging me,
and i'm sure he wants to keep the total bid under $20k, for sticker shock reasons.
he's also said he's seen jobs with enough wood rot and termite damage to rival
the original quote, positioning me for any bad news.
i boracared the attic and crawl space with a thick application when i bought the
house, and that should have calmed down the termites, but one doesn't always
know how bad it is until stuff is opened up, does one?
i'm sticking in a couple of roof jacks and a couple 6" vents when this gets redone.
also, a 2" roof jack for a service upgrade. i've never upgraded the service, and will
do so after the roof goes on. i'd do it before, but there are constraints preventing that.
it is what it is.