Insulating A Roof With Rigid Foam

A continuous layer of rigid foam insulation in wall and roof assemblies leads to lower energy consumption an environmental plus to be sure.

Insulating a roof with rigid foam.

It can be applied on the roof floor and walls and it s most widely used in structural insulated panels and insulated concrete forms. Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance. Insulating a metal shed roof with rigid foam can be done one of three ways by laying the board prior to applying the roof by removing the existing roof and installing new foam board or by insulating the existing metal roof from the inside. Insulated roof assemblies can be vented or unvented.

Install nailbase for cladding. Eps is by far the most versatile of the three rigid insulation options. Rigid foam boards come in different material compositions varying thicknesses and different insulating r value properties. But one thing that some builders don t like is the high global warming potential of some blowing agents used to make the foam.

Install rigid insulation board in multiple layers with joints offset vertically and horizontally between adjacent layers. There are at least two good reasons why this approach makes more sense than installing the insulation under the roof sheathing. Nail it around the edges with roofing nails.