Exterior Roof Insulation Details

The roof consist of sheathing and shingles on the exterior and the cedar planks on the interior.

Exterior roof insulation details.

Exterior roof insulation retrofit unvented roof covering the roof of an old house with a blanket of insulation makes the house more comfortable and it cuts energy use. There are at least two good reasons why this approach makes more sense than installing the insulation under the roof sheathing. It makes a lot of sense if the rafter cavities are already insulated and it is most affordable when the roof needs replacement. Plywood or osb roof sheathing can be installed over exterior insulation layers using long exterior grade screws.

Since there is no insulation in the summer months we can feel the heat in the upstairs in the morning and quickly begins to work it s way done in the late morning. Not only do we withstand hail damage but our roof boards maintain their bond to the roof membrane lowering the likelihood of a catastrophic roof failure. The screws must be long enough to penetrate an adequate depth into the roof framing. 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.

I like the existing cedar and don t want to cover it up. Insulated roof assemblies can be vented or unvented.