How To Install Foam Board Insulation On Roof

More insulation on the exterior is good.

How to install foam board insulation on roof.

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. To save a step i would recommend using a nailbase panel foam preadhered to osb or sometimes plywood on one side only see photo facing page. Over the foam you will need something to nail the roofing to usually a solid sheet of plywood or osb.

Now that you know your options there are just a few more tips that you might need before you get started with installing your rigid foam insulation. It will degrade its r value. Insulation board should be added between the old and new roof systems to ensure proper insulation and to reflect heat from the outside. Once the roof demo was complete and the flat roof was cleared of any remaining debris some rotted 2x material around the perimeter of the roof was replaced.

All foam boards absorb water vapor. Flat roof insulation installation the rigid foam board insulation we used was 2 thick and came in 4 x 8 sheets. It will help you to eliminate problems that may come when the house becomes extremely cold in the winter and terribly hot in the summer. Available in both foam and rigid form choose the board type.

Cover the insulation with a vapor barrier before you install it. There are at least two good reasons why this approach makes more sense than installing the insulation under the roof sheathing. The snugness of the foam itself should be sufficient to hold the strips. Keep foam board insulation away from direct sunlight prior to installation.