A sheet of foam insulation, also called rigid foam insulation or foam board insulation, is a polyurethane panel material typically used in home or commercial construction to shield a building from environmental variances such as heat and cold. The material is manufactured in various depths and sizes.
Rigid foam insulation is made of a cellular plastic that is molded or extruded into a firm sheet of foam. The material is sold at many major home improvement stores in panels that usually measure 8 feet by 4 feet and vary in thickness from 0.5 inch to 2 inches. The facing of these panels can be covered in glass fiber, metals, craft paper or oriented strand board. Many rigid foam insulation systems include a tongue-and-groove feature that allows the panels to interlock together.
Although its primary use is in construction, rigid foam insulation in sheet form has been used as a medium in an array of other arenas because of its lightweight and moisture-resistant properties. It is often used in set design in theatrical productions. Paint and texture can be applied to the panels to create scenery. The panels can be cut and shaped using a razor knife, a heated cutting tool or side-grinder.