Extending Roof Rafters For Insulation

In finished attic rooms with or without dormer insulate 2a between the studs of knee walls 2b between the studs and rafters of exterior walls and roof 2c and ceilings with cold spaces above.

Extending roof rafters for insulation.

Its versatility is the key to its popularity whether being used to achieve. 2d extend insulation into joist space to reduce air flows. An efficient room in a roof in a new build property where over rafter insulation is not desirable. Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect.

Images courtesy simpson gumpertz heger. How to install rafter insulation. The outer ends of a roof s rafters the sloped members that give the roof its pitch provide shade divert rain and create soffit space for attic ventilation. Apply insulation between rafters when finishing an attic into a heated room or when building a cathedral ceiling in the home.

For instance if the roof has 2 by 6 rafters and you want r 30 insulation which is standard in many communities you can add a 2 by 4 which will give you an 9 inch rafter space. By installing high density 8 inch fiberglass batt insulation the rafters will then meet an r 30 roof insulation standard. How to extend rafters. After a bit more destruction and dust it is time to look at how we increased the rafter depth in preparation for the insulation.

Almost there with the old fo. The roof rafters are currently about 20 apart made of 2x6 s the house was built in 1915. Ibc dictates acceptable placement and composition of roofing materials in chapter 15 but describes required thermal efficiency of the roof in chapter 13 which references the international energy conservation code iecc the minimum required thermal resistance varies. Roof insulation configurations for unvented rafter truss assemblies.

I ve been talking with the gc about approaches to try and increase the depth of the roof rafters to get in more insulation while at the same time allowing a baffle for air flow i have a slate roof.