Dormer Attic Insulation

This method requires the use of 150mm thick insulation between the rafters and a 50mm air gap to prevent cold bridging occurring.

Dormer attic insulation.

Dormer roofs are roofs that contain rooms and can present considerable challenges when it. In an existing dormer or 1 5 storey home icynene spray foam insulation can be easily fitted to the difficult to insulate areas such as crawl spaces and closed sloping attic sections using our unique cannon tip application method and in areas totally inaccessible icynene can be injected through the plasterboard. Fiberglass batts are the worst possible insulation to use in rafter bays because of all insulation types fiberglass is the most permeable to air. If interior air gets into the rafter bays the fiberglass batts do nothing to prevent the warm moist air from contacting the cold roof sheathing.

There are a number of options for insulating a new dormer roof. According to the oak ridge national labratory the open joist ends below the knee wall should be sealed with rigid foam high density cellulose or batt insulation. The depth of your rafter will determine what size of insulation should be used and in turn what size of plasterboard slab should be fitted to achieve current building regulations. To insulate an existing dormer we outline three of the more common methods below.