Insulating Underside Of Roof Deck

In addition to installing the foam board on the underside of the roof deck you can attach it to the bottom edges of the rafters in the same manner you would hang drywall.

Insulating underside of roof deck.

Fiberglass insulation is installed between the rafters as shown schematically below. It is about three feet off the ground and has mesh stapled to the underside to prevent bugs from making their way in. Staple plastic or foam baffles to the roof sheathing near the eaves to keep the material away. This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic.

This type of system can also be found in low slope residential buildings in inner city areas. This construction approach was first used in the 1970s and it has been implemented much more widely since it was first included in the international code council s icc model building code in 2007 irc section 806 4. Insulating the underside of deck. Insulation and air barrier are applied directly to the underside of the roof deck are common in applications where designers are seeking cost effective and energy efficient roof assemblies.

For some building uses the ceiling might be absent. Our deck has been updated to a three season porch. You can then install. Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.

A wood deck roof system. Low slope and steep slope unvented roof systems i e. For the same reason insulation shouldn t touch the roof s underside. Install insulating sheathing above the roof deck on existing homes.

Polyurethane spray foam metal roof insulation in order to add moisture barrier under metal roof you can spray the undersides of the roof by using a thick layer of polyurethane spray foam. Remove existing roofing and non adhered underlayment to expose roof sheathing.