Spray Foam Metal Roof Wood Purlins

Sequentia wood solid roof panel closure.

Spray foam metal roof wood purlins.

Spray foam directly on metal building barndominium i have a 30x60 metal building barndominium in the san antonio tx area. Install a layer of closed cell spray foam against the underside of the steel roofing or roof sheathing and fill the rest of the purlin cavity with an air permeable insulation. Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point. There seem to be no chemicals in spray foam that could react with steel or the galvanized protective coverings on the metal siding and roofing panels.

The big picture concern is actually more about trapped moisture than whether the substances that make up spray foam insulation will corrode steel or metal sheets. Another thought if you plan to spray foam insulation onto the underside of a metal roof on purlins install some type of underlayment tyvek etc over the purlins before applying the metal. We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof. If you choose to omit the plywood from a residential construction install a vapor barrier between the purlins and the metal roof or plan to spray closed cell foam insulation between the rafters to eliminate the temperature differential between the air in the building and the metal.

For pricing and availability. It has red iron main frame with all 2x6 wood framing 16 on center on walls in between i beams and 8 steel purlin on roof. This type of assembly is designed to dry to the interior so the assembly should never include an interior polyethylene vapor barrier. But a preinstalled membrane may be even more effective at removing condensation.

The insulation then attaches to the underlayment and should you ever have to remove a piece of metal for whatever reason you do not destroy the. Personally i am hard pressed to see how it is the application of closed cell spray foam insulation on the interior of the steel roofing would influence the life of coatings on the exterior. The problem with using. Union corrugating metal solid roof panel closure strip.