Roofing Foam Board

Foam board insulation is easy to cut with a circular saw with a masonry blade or scored with a utility knife and snapped like you would drywall.

Roofing foam board.

Rigid roof insulation board. After the roof deck is prepared the rigid foam boards need to be cut to size to fit snugly together on your roof. The 4 x8 sheets of rigid foam board insulation were then laid out in a staggered pattern across the entire surface of the flat roof. Use a premade kit for this type of project.

Rigid foam is produced in various size panels 4 ft x 8 ft 4ft x 4ft etc. If you want to install rigid foam above your roof sheathing in climate zone 3 then 1 2 inch of rigid foam board is not ideal this rigid foam layer needs a minimum r value of r 5 and that s impossible with 1 2 inch of foam. For a basement remodeling project consider insulating basement walls with foam board. For new construction use rigid boards to insulate slabs and the outside of foundation walls.

The panels need to fit together tightly to help prevent warm air from leaving the top of the building. Attach to deck board. Attach the tongue and groove insulation boards to the concrete wall with adhesive. Composed of a closed cell polyisocyanurate foam core bonded in the foaming process to retroplus roof board on one side and a glass reinforced facer on the other.

Some parts of the country necessitate a vapor barrier under the rigid insulation however this wasn t necessary in our case.