Rigid Foam Has A Range Of R-Values Rigid foam, or foam board insulation, is another popular option for the garage. The sheets' thickness varies between 1/2 inch to 4 inches thick, which gives the ...

To get the most R-value with the least thickness, use batt insulation with higher R-value per inch in combination with rigid foam insulation. Rigid foam sheeting has an R-value ranging from R-5 to ...