Types of Roof Insulation
The following table lists the types of insulation that are used in low-slope roofing (or found in existing roofs). These insulation materials usually take the form of 4’ x 4’ or 4’ x 8’ rigid boards. They are normally secured with adhesives or fastener systems, but they may be loose-laid in ballasted roof systems, which depend on the weight of the ballast to hold the entire system in place.
These types of insulation are used in above-deck insulation applications, which means that they are installed over the roof deck, and are considered a part of the roof system or roof assembly. Steep-slope or pitched roof systems will almost never include insulation; in steep-slope construction, the insulation will be installed below the roof or above the ceiling.