Insulation Question

Roy,
The literature you linked to goes into special considerations for climate zones 6 and 7, including insulating panels on the roof surface; the colder the climate, the thicker the panels should be. They also recommend closed cell more strongly for up north. All I see around here is open cell, and it generally works like a charm, bringing energy bills way down.

I do alot of work in this area. You have to take a plug out to look at the application, if the mixture is wrong it can have cavities or the bubbles will be too big which can cause a lot of issues. I had a manufacture show me a lots of things to inspect for, which helped alot. I’ve also seen it cavitate where they spray the lift too thick and the foam will delaminate from what it’s being sprayed onto. I just had an energy star home this year that I basically made them redo the whole house because of this. Another big problem I see is they spray it too thin and it can cause vapor drive through the roof decking which will cause major problems with the roof decking. I usually stick a coat hanger in it at random places to take depth measurements and cut out a core to see how the lifts look. As for the insulation on the ceiling, that’s not really a great practice. You want the now semi-conditioned attic to communicate with the house which the fiberglass will reduce. We do not require transfer grills or ducts to the attic because it communicates with the rest of the house pretty well through the top plates. Unlike a crawlspace that is semi-conditioned or conditioned. The main reason a conditioned crawlspace has a transfer is so the supply air pushed into the crawlspace has a way back to the return if there is not one in the crawlspace.

Here is a bunch of good information as well, Insulation Wizards.

I have also seen a lot of open cell that has been working out well for people. Keeping them cool in summer, warm in the winter, and their bills lower year round.