Extending Roof Rafters For Insulation

Batts between rafters in would require adding ventilation between the insulation roof deck.

Extending roof rafters for insulation.

Arguably the most popular pitched roof solution installing insulation between and under the rafters uses the depth of the structural timbers to best effect. 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. After a bit more destruction and dust it is time to look at how we increased the rafter depth in preparation for the insulation.

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. 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. An efficient room in a roof in a new build property where over rafter insulation is not desirable. 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.

Images courtesy simpson gumpertz heger. How to extend rafters. Garages built without attics are. The roof rafters are currently about 20 apart made of 2x6 s the house was built in 1915.

Roof insulation configurations for unvented rafter truss assemblies. Almost there with the old fo. How to install rafter 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.

By installing high density 8 inch fiberglass batt insulation the rafters will then meet an r 30 roof insulation standard.