What is the R value of the foam?
First thing to know is that there are two types of foams being installed into homes in Canada. First is medium density foam like Walltite. This product uses inert gases other than air to insulate with. The gas is trapped in the cell and held there for a lifetime. This being said the foam is always rated in aged terms known as “Long Term Thermal Resistant Values” or LTTR for short. Walltite has the following LTTR ratings for thicknesses: 1″ = R6.3 2″ = R13.1 3″ = R20.4 4″ = R29.2 Low density foams are water blown and use steam to make the cells rise and traps carbon dioxide in the cells. These foams do not have LTTR ratings and the range from R 3.1 – 3.8 per inch.
