I had my shop walls and roof sprayed, just like yours with 2" closed cell foam. This is what I recommend. It would be difficult for the installed to spray 1.5 or 2" and get any consistency. I would just pay for the 2" and you will get at least 2". In the northern climates 2" is the minimum that can be used and considered a vapor barrier. Since you are spraying directly to the exterior metal (this is what I did), you need the closed cell foam to act as a vapor barrier.
What others have said is true, you will have to paint over it with some type of paint to protect it from UV light, or cover it with liner panel, drywall, etc.
The numbers on closed cell are R7 to R7.5 per inch. There is no comparison in my opinion between spray foam and fiberglass. The problem with fiberglass is that you need to COMPLETELY seal off and have an air tight building and vapor barrier in order for the fiberglass to work. Then you have to fill each and every cavity completely full, but not stuffed too tight either... The R values on fiberglass are determined in a lab under optimal, perfect, air tight installation. Because no real installation is anywhere close to being sealed or installed perfectly, you never get anywhere near the effective R value your fiberglass states on the package. With foam, it seals every crack and crevice air tight and you get a perfect air tight install, and actually get the R value you paid for.
When dealing with building codes, the lawmakers, inspectors, etc have to go by measurable numbers, so the best they can do is say you need Rx in your walls and Ry in your ceiling and they determine if it's done correctly by using a ruler. Often times to get the "number" that the inspector wants, people do 2" of spray foam, and then fiberglass on top of that, just to appease the AHJ. The fiberglass does little extra but appease the inspectors, and you sure wouldn't want to spend the huge money on thicker foam, just to get an arbitrary number. For my shop I'm doing the 2" foam and then R19 fiberglass (flash and batt).
Your quotes are in line, summarizing what others have said, it sells for about $1/square foot at 1", $2 for 2", $3 for 3", etc. Also, the color is marketing and dye. Why is Owens Corning fiberglass pink? It's dyed that color for product recognition.
What others have said is true, you will have to paint over it with some type of paint to protect it from UV light, or cover it with liner panel, drywall, etc.
The numbers on closed cell are R7 to R7.5 per inch. There is no comparison in my opinion between spray foam and fiberglass. The problem with fiberglass is that you need to COMPLETELY seal off and have an air tight building and vapor barrier in order for the fiberglass to work. Then you have to fill each and every cavity completely full, but not stuffed too tight either... The R values on fiberglass are determined in a lab under optimal, perfect, air tight installation. Because no real installation is anywhere close to being sealed or installed perfectly, you never get anywhere near the effective R value your fiberglass states on the package. With foam, it seals every crack and crevice air tight and you get a perfect air tight install, and actually get the R value you paid for.
When dealing with building codes, the lawmakers, inspectors, etc have to go by measurable numbers, so the best they can do is say you need Rx in your walls and Ry in your ceiling and they determine if it's done correctly by using a ruler. Often times to get the "number" that the inspector wants, people do 2" of spray foam, and then fiberglass on top of that, just to appease the AHJ. The fiberglass does little extra but appease the inspectors, and you sure wouldn't want to spend the huge money on thicker foam, just to get an arbitrary number. For my shop I'm doing the 2" foam and then R19 fiberglass (flash and batt).
Your quotes are in line, summarizing what others have said, it sells for about $1/square foot at 1", $2 for 2", $3 for 3", etc. Also, the color is marketing and dye. Why is Owens Corning fiberglass pink? It's dyed that color for product recognition.
