Thank you, Allison. We have a split system unit (actually 5) with the heat being propane. The foam guy said that it needed ventilation, so completely sealing the attic wouldn't be a good idea. It sounds like you are saying that the systems need to be vented out of the attic or replaced with some type of closed system. But I shouldn't bother spraying if the plan is to leave the soffet vents open. Is that correct?

How Much More Expensive Is Spray Foam

A: It can be applied in the similar manner that we apply paint. We can use a paint roller to apply it without any hassle and use of special tools. You can also check the specific manual of instructions from the maker for particular directions. You should also check if it requires single or double coating or the use of a primer before its application.
The complete line of JM open- and closed-cell spray foam insulation solutions provide superior thermal and energy performance, as well as advanced air, moisture and sound control in any climate. These products can be used in interior and exterior walls, unvented and vented attics, floors, ceilings and crawl spaces. Plus, using spray foam can reduce air leaks and create a more comfortable, energy-efficient home – meaning you could see more energy savings every month.
I started using Gaco years ago primarily to solve ponding water Problem. It has work well, solved my problems with other roofing options and repairs as well as many other Flat roof issues.  My only problems were experienced when I did not clean the surface well enough for good adhesion.  Follow the Instructions.  Great product and highly recommended. .
These coatings contain various types of acrylic polymer, and are typically formulated to help extend the coating’s life and improve durability. Acrylic coatings are available in a number of colors but are most commonly used as white reflective coatings. Thanks to its durability and low cost, many contractors and facility managers believe this to be the best roof coating.
That’s $58.3 Billion dollars. That’s roughly how much money we wasted in 2010 in the US according to the Department of Energy because of air leaking out of our building envelopes. If your building leaks energy, you’re paying more for energy than you need to. Clearly you’re not alone. If you’re ready to claim your share of the savings, it’s quicker and easier than you think.

Roof Coating Seal