Spray Foam Roof Assemblies

On exterior spray foam roofing applications the roof sealing foam should be coated with a white roof coating after curing.

Spray foam roof assemblies.

R 46 unvented roof assembly two layers of r 6 5 inch rigid insulation yielding a total combined thickness of 2 5 inches. Two layers are preferable to one layer due to increase in air flow resistance. Since a spray foam system consists of spray foam coating and granules after 10 20 years some of the coating and granules will naturally wear away. Spfa 138 guideline for roof assembly evaluation for spray polyurethane foam roof system 8 pages including roof surface assembly considerations.

Image courtesy of d7 spray foam insulation houston tx. Unvented roof assemblies with ccspf work well in all climate zones and serve several important functions. A very energy efficient enclosure results. Spfa 130 spray polyurethane foam roofing updated spf roofing brochure the high performance cost effective weather resistant solution for commercial industrial and residential structures.

Or 25 mm minimum thickness and vapor retarder at 2 in. Closed cell spray foam acts as an air barrier at 1 in. Open cell spray polyurethane foam or closed cell spray polyurethane foam ccspf insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in. Or 50 mm minimum thickness and therefore does not need an additional vapor retarder in cold climates.

Looking upward through the open ceiling if the exterior wall and roof deck assemblies both contain spray foam then a continuous insulation and airtight layer is established from the base of the walls to the peak of the roof. Layers of rigid insulation have staggered joints to facilitate airtightness. There is no potential for condensation until interior moisture levels exceed 45 rh at 70 f during the coldest month. This roofing foam insulation is a higher density 3 1 lb ft foam that cures to rigid in several minutes.

A spray foam roof can be the last roofing system you ll ever need on a building. Unvented roof assemblies should be insulated either with air impermeable insulation rigid foam or spray polyurethane foam or with a combination of foam and air permeable insulation. The foam never gets touched and never loses r value. Icynene s products can be used in fire compliant assemblies noted in the requirements of chapter 26 of the international building code icynene spray foam insulation products have the flame spread and smoke developed indexes required have been tested in accordance with and comply with the acceptance criteria of nfpa 285 and there are many wall and ceiling assemblies that contain icynene.

Unvented roofs with spray foam applied to the underside of the roof deck have been used since the mid 1990s.