(1) Not all product sizes are available in all regions.
(2) R means resistance to heat flow. The higher the R-value or RSI (R-Value Système Internationale), the greater the insulating power. R-values are expressed in ft2• h•°F/Btu. RSI values are expressed in m2 °C/W. R-value determined by ASTM C518 as per CAN/ULC S701-97 (supersedes CAN/CGSB 51.20-M87).
(3) Vertical compressive strength is measured at 10% deformation (5% for STYROFOAM™ Brand HIGHLOAD Insulation - 40, 60 and 100 products) or at yield, whichever occurs first. Since STYROFOAM™ Brand Extruded Polystyrene Insulation products are visco-elastic materials, adequate design safety factors should be used to prevent long-term creep. Adequate design safety factors are needed. For more information visit our Answer Center.