Open cell foam has been proven to have insufficient vapour resistance during the cold Manitoba winter months and because of that we feel it is not suited for our climate and therefore we do not spray it for any application. 2lb Closed cell SPF walls however has been proven to have sufficient vapour resistance to maintain sheathing moisture contents for the same challenging interior conditions.
Open cell SPF has an R-value of 3.7 per inch. It insulates by trapping air in the foam cells. It acts as an air barrier and noise absorber. Open cell SPF is softer and more flexible than rigid closed cell foams, and, in general, is best suited for mixed or warm climates.
Closed cell foam has a higher R-value (over 6 per inch), and is an excellent air and moisture retarder. It provides structural enhancements to buildings where it is sprayed, and is effective in all climates. In cool climates where the moisture drive is from the inside to the outside of a building, closed cell SPF can eliminate condensation on the sheathing, thus helping to prevent the growth of mould in these areas.