Foam Board Roof Decking

Given that it seems that the ideal roof deck build up would consist of.

Foam board roof decking.

This section outlines the conditions for unvented attic roof assemblies. At 600 board feet you can get the spray foam cost down to about 1 20 board foot compared to 3 35 bf ft in the 12 b f. Note that table r806 4 indicates the amount of insulation above the roof deck or air impermeable insulation below the roof deck required for condensation control assuming minimum required total insulation as indicated in section n1102 building thermal envelope. After the roof deck is prepared the rigid foam boards need to be cut to size to fit snugly together on your roof.

Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. For new construction use rigid boards to insulate slabs and the outside of foundation walls. Rigid roof insulation board. 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.

Foam on the underside of the roof deck would provide a more reliable air seal but has long term issues related to roof rot since the unvented roof deck would get a lot of. Position the foam board between the rafters and push it upward until it fits snugly against the underside of the roof deck. Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls. The snugness of the foam itself should be sufficient to hold the strips.

1 2 rigid foam board 3. The panels need to fit together tightly to help prevent warm air from leaving the top of the building. I m planning on open cell spray foam on the underside of the roof deck. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems.

Frothpaks or 5 for 1 part foam cans. I am curious as to whether the first layer of osb could be omitted if the foam board did not react to. Attach to deck board. Attach the tongue and groove insulation boards to the concrete wall with adhesive.

Top surface is sealed with this special coating to reduce excessive asphalt absorption in hot asphalt applied roofing systems. 1 4 dens deck roof board. Use a premade kit for this type of project. 1 4 spans flute widths up to 2 5 8 flexural strengths parallel lbs.

Rigid foam is produced in various size panels 4 ft x 8 ft 4ft x 4ft etc.