Exterior Roof Insulation Details

Minimum nail length must accommodate sheathing and penetrate framing a minimum 1 inches.

Exterior roof insulation details. Install nailbase for cladding. Single ply roof systems can provide an easy to install seamless roof assembly. Roof edge detail overhang extended to hide the thickness of the over roofing rigid insulation. Termites can tunnel from the soil up behind the foam panels and attack the structure of a house without being noticed.

Rigid insulation layers exterior to existing roof sheathing must provide sufficient thermal insulation r value to control condensation risk see climate specific guidance. Insulated roof assemblies can be vented or unvented. There are lots of different ways to insulate this type of roof but one of the best methods calls for the installation of rigid foam insulation above the roof sheathing. Nailbase must be vented in high snow load areas.

Now comes the really really big point. New roof sheathing on top can extend out to create a new roof overhang. Install two layers of insulation to the roof staggering the seams offsetting the joints and taping outer layer. The binder includes product specifications detailed drawings and illustrations technical datasheets and a number of informational brochures.

There are at least two good reasons why this approach makes more sense than installing the insulation under the roof sheathing. Gable end detail overhang cut and then rebuilt to hide the thickness of the over roofing rigid insulation. Rockwool multifix is a mineral fiberglass faced stone wool product that can be installed under many single ply membranes. Current pneumatic nailers have maximum fastener lengths of 3 to 3 5 which limits insulation thicknesses to 1 5 max.

Install roofing underlayment flashing and cladding as per best practices. 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. Building codes are clear. If you are planning to install metal roofing then you would install asphalt felt above the rigid foam followed by 1x4 or 2x4 purlins 24 inches on center then the metal roofing.

Single ply roof insulation. Detail drawings illustrations lapolla distributes an architectural binder available in print and electronic format. Current building code does provide prescriptive means to attach cladding over exterior insulation table r704 3 note v. The easiest way to insulate your roof is with one or two layers of rigid foam insulation installed above the roofing.