Roofing Foam Board

Attach to deck board.

Roofing foam board.

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. Rigid roof insulation board. Attach the tongue and groove insulation boards to the concrete wall with adhesive. Retroplus roof board is an expanded perlite mineral aggregate board.

After the roof deck is prepared the rigid foam boards need to be cut to size to fit snugly together on your roof. 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. 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.

Some parts of the country necessitate a vapor barrier under the rigid insulation however this wasn t necessary in our case. 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. Rigid foam is produced in various size panels 4 ft x 8 ft 4ft x 4ft etc. Use a premade kit for this type of project.

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.