Donna writes from Medicine Hat, Alberta: "Is it okay to compact the pink insulation? The insulation we have is 10" thick and we need it pressed down to fit into the 2x4 area. Can this be done without harming the R-value??"

Answer: Fiber glass insulation works on the principle of trapped air pockets. By compressing fiber glass insulation, you decrease the amount of air trapped in the material. For example, compressing R-20 batt insulation, which is 6" thick, into a 2x4 wall cavity, which is 3-1/2" thick, will give you an approximate R-14 value. It is better to buy the product that best fits in the space.