I had a 24' by 8' high wall that I was reinsulating at home that I wanted to air seal with foam. It was a small job for a contractor and would have been expensive so I sprayed it myself. I bought mine from Foam it Green but there are several manufactures on the internet. Overall it worked out well although I did learn some things. I sealed the exterior wall with about 1 to 2" of foam while the remainder of the 6" stud cavity was filled with the fiberglass I had removed. I also installed 1/2" of ISO foam board across the interior face of the wall and then plant to sheetrock after taping off the joints on the iso board.
The kit I bought had gloves, tyvek suit, googles and lots of spare nozzles. It sprayed real well and developed a relatively smooth surface for the first 2/3rds of the tanks. After that it got real "chunky" like spraying chunks of popcorn, so the resultant surface looked very rough. It was okay in a wall cavity but wouldnt be acceptable to me for something in view. I had more foam than I thought and didnt want to try to store it, so I did try some deeper sections of foam and did confirm that the reaction is exothermic and spraying much more than 4" wasnt good due to the heat generated. I also suspect that the foam "works" more in thick sections and in one or two spots it shrunk a bit and pulled away from the wall in the cavity.
One thing I confirmed is to cover everything in the area due to potential backscatter and overspray. I also urge anyone to wear the safety gear, I had a chemical/organic half mask respirator with a hepa filter on and would urge others to do the same as there are fumes when sprayed but they disapate rapidly.
The other item to note is that there is a lot of waste to get rid of when done including two small dot steel cannisters and a hose assembly.
Given this experience I will probably do my own sills unless a contractor moves into the area, but will try to plan that the areas that are visible will be sprayed first, I will probably fill the joist pockets afterward and finish with fiberglass to hide the rough stuff at the end of the tanks.
The kit I bought had gloves, tyvek suit, googles and lots of spare nozzles. It sprayed real well and developed a relatively smooth surface for the first 2/3rds of the tanks. After that it got real "chunky" like spraying chunks of popcorn, so the resultant surface looked very rough. It was okay in a wall cavity but wouldnt be acceptable to me for something in view. I had more foam than I thought and didnt want to try to store it, so I did try some deeper sections of foam and did confirm that the reaction is exothermic and spraying much more than 4" wasnt good due to the heat generated. I also suspect that the foam "works" more in thick sections and in one or two spots it shrunk a bit and pulled away from the wall in the cavity.
One thing I confirmed is to cover everything in the area due to potential backscatter and overspray. I also urge anyone to wear the safety gear, I had a chemical/organic half mask respirator with a hepa filter on and would urge others to do the same as there are fumes when sprayed but they disapate rapidly.
The other item to note is that there is a lot of waste to get rid of when done including two small dot steel cannisters and a hose assembly.
Given this experience I will probably do my own sills unless a contractor moves into the area, but will try to plan that the areas that are visible will be sprayed first, I will probably fill the joist pockets afterward and finish with fiberglass to hide the rough stuff at the end of the tanks.
