Rigid Insulation On Top Of Roof Deck

Rigid foam insulation is available in two main types.

Rigid insulation on top of roof deck. The panels need to fit together tightly to help prevent warm air from leaving the top of the building. Installing rigid foam insulation on top of roof sheathing is a great option for commercial buildings and homes with limited space. After the roof deck is prepared the rigid foam boards need to be cut to size to fit snugly together on your roof. The purpose of the requirement that rigid foam installed above roof sheathing meet certain minimum r values is to ensure that the roof sheathing stays warm enough during the winter to avoid moisture accumulation and possible sheathing rot.

Most types of rigid foam insulation have a higher r value per inch than fiberglass batts. Polystyrene foam and foil faced polyisocyanurate foam. Foamular xps insulation products 404 604 404rb and 604rb are used in prma applications. Install nailbase for cladding.

Attach to deck board. Rigid foam also does a better job of stopping air flow as long as it s carefully sealed at the edges. Rigid foam is produced in various size panels 4 ft x 8 ft 4ft x 4ft etc. Many homes in more urban areas or other places with dense populations are opting for this method because they can better optimize space.

The 6 inches of rigid insulation added to the top of the existing roof deck needed to be done in a manner that was invisible. Both install in the same manner but the foil faced product offers slightly more r value. An excellent fire barrier densdeck roof boards feature a noncombustible core and inorganic surface that offer greater fire protection than other conventional commercial roofing products when applied over combustible roof decks and steel decks. Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance.

Install roofing underlayment flashing and cladding as per best practices. Nailbase must be vented in high snow load areas. Densdeck roof boards are fm tested and approved as the only 1 2 gypsum product to meet the. Foamular xps insulation is the only insulation used in prma roof systems due to its excellent resistance to water absorption compared to any other type of rigid board insulation.

They had to look original. The trim the frieze boards the fascia and the overhangs all had to look like they belonged.