Foam Insulation Above Metal Roof

Polyurethane spray foam metal roof insulation.

Foam insulation above metal roof. Lstiburek takes blame for bad language. Your metal roof expands when it s hot and contracts when it s cold. A vented attic is basically outdoors so installing rigid foam above your roof sheathing is a waste of money and a waste of rigid foam. This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic.

Metal roofs are made from steel copper or aluminum panels. The concern of manufacturer mbci is over who is going to verify that the foam will not cause corrosive damage over time to the roofing. Spray foam spray foam is the most popular insulation method for the metal roof because it s highly effective. You can add insulation to an existing metal roof by going into the attic and stapling a foil barrier to the rafters.

Metal roofing manufacturers typically extend a 25 year warranty. It s not coming from above the roof and it s not some new moisture source resulting from the spray foam. Remove existing roofing and non adhered underlayment to expose roof sheathing. If you have a vented attic it makes no sense to install rigid foam above the roof sheathing.

They are used in commercial and residential structures to protect against weather and other exterior elements. This is different from the normal roll up type of insulation as it comes in panels rather than paper covered fiberglass. Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing. This foam can be used on either the outside or the inside of the sheathing.

This is a form of polyurethane insulation which r value is determined by the inches. The spray can be basically applied on top or bottom of the metal roofing surfaces. A spray polyurethane roof can be installed over a leaking metal roof. It s effective at preventing condensation and rodent infestation.

If the shiny side of the barrier faces the roofing hot air will circulate in. Foam insulation can be used in existing roof structures. The best material for use with metal roof insulation is in the form of foam batting. You might as well put the rigid foam in the branches of a tree in your back yard.

Most of the time extreme heat shifts cause that leak. Compared to the fiberglass batts this insulation is much better. Install insulating sheathing above the roof deck on existing homes. The challenge comes when you combine systems spraying foam onto the metal roofing itself.

Combining foam and metal roofing.