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.

By installing high density 8 inch fiberglass batt insulation the rafters will then meet an r 30 roof insulation standard. 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. Hack n stack sealed foam board between the rafters would be better since it s at least an air impermeable insulation but even that would require a vent gap below the roof deck to meet code and you d still be under r38 on that 2x6 rafters unless you.

Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect. 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. How to install rafter insulation. Its versatility is the key to its popularity whether being used to achieve.

Apply insulation between rafters when finishing an attic into a heated room or when building a cathedral ceiling in the home. Almost there with the old fo. An efficient room in a roof in a new build property where over rafter insulation is not desirable. Batts between rafters in would require adding ventilation between the insulation roof deck.

How to extend rafters. 2d extend insulation into joist space to reduce air flows. 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. After a bit more destruction and dust it is time to look at how we increased the rafter depth in preparation for the 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.