The “R” value is the most important aspect of choosing insulation. It is the measure of the product’s resistance to heat transfer and is a guide to its performance as a heat insulator.
Higher R-values are more effective at maximizing your energy savings and comfort. The higher the “R” value, the more effective the insulation is in reducing heat flow in or out of your home.
For reflective foil insulation, the quoted “R” value refers to the total resistance of the structure (roof or wall) after the insulation has been installed. This accounts for the resistance of any ‘air gaps’, roof and ceiling materials and how the insulation is installed.
In general, to know what level of R Value you should look for in your insulation, the more temperature fluctuates in summer and winter where you live, the higher the R-value you will need.
Foamex Expanded Polystyrene’s cellular structure means it is stable and will not settle. Installed correctly without damage it will not deteriorate with age and will deliver constant R values for the life of the building.