Insulating Underside Of Roof Deck

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 underside of roof deck.

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. It is about three feet off the ground and has mesh stapled to the underside to prevent bugs from making their way in. Insulating the underside of deck. Fiberglass insulation is installed between the rafters as shown schematically below.

Our deck has been updated to a three season porch. For some building uses the ceiling might be absent. A wood deck roof system. You can then install.

Install insulating sheathing above the roof deck on existing homes. Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls. This type of system can also be found in low slope residential buildings in inner city areas. For the same reason insulation shouldn t touch the roof s underside.

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. Low slope and steep slope unvented roof systems i e. 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. If you re insulating from scratch put the right vapor barrier in the right place.

This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic. 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.