D. Boone - 2 links
Demilic &
Building Science both cover the items you need to consider for spraying in the attic
As I recall the only code approved system is Closed Cell foam which Icenyne doesn't carry. They do try to get past this with a coating that they apply to the foam after it is sprayed. The reps I talked to have failed to provide any testing sheets or code approvals for this method though. I love the reps that say you should use there system - because if there is a roof leak you will not know it - ours water comes straight down.
The last house I did used the Demilic system & it worked great. It snowed the very next day & the house stayed @ 60 without additional heat.
You will need an ERV to help eliminate humidity & indoor pollutants. Your AC & Heater should run more efficiently (Assuming your ducts are located in this area)
Cost - Closed Cell is about 2 times the price of Open Cell - some installers do what is called a Splash & Dash (2" inch spray of CC & then fill in the Cavity with OC) to help keep costs down - I went with a 2, 2" lifts & left it at that
OCRS - there is some good info, but it is old & there is allot of adversion to change in there with no knowledge to back up some of it
Confused Plumber that wants to be a Electrician
I assume you are talking about the coating put over Icenyne after it is applied - It is meant to reduce vapor transmission to the sheathing & to CTMA