Fire block spray foam is what it says it is. The project is going well and application is straight forward. I am obviously using more product than I first calculated. Overall quality product.
I am using this product in my wood shop and it has been great. fI was going to have my shop professionally done until they told me I had to move everything out for them to do it. I found this product and can take my time and move a few things from a section at a time without having to move everything out. I'm on my third case and it has worked flawlessly. I did find it works best if you run gun cleaner through each time you change cans and use a new tip each can change and you will be very happy with the results.
The purple spray foam is a good product that covers well on vertical surfaces as long as you keep it thin and do a second coat, I did not see 20 board feet at 1 inch thickness though. i have tried every method going through 96 cans and 2 guns learning. Advice: cover everything and wear the Tyvek suit.