Foam board insulation is easy to use and a great DIY way to add some insulation. It comes in standard-size 4×8 sheets and smaller sizes, in thicknesses from 1/4-in. to two inches. Some types of ...

The term "Styrofoam" is actually the brand name of a rigid blue insulation that the Dow Chemical Company makes, not the lightweight white foam you find in takeout coffee cups. That said ...