NettetCeiling Insulation - R-30 in 2x6 rafters. I’m converting attic space into habitable space and I’m required to insulate the ceiling to R-30. The issue is that I only have 2x6 … NettetPut standard fiberglass insulation that's appropriate for the climate (probably R-38) between the joists. Since this insulation will be 12 inches thick, the top will sit above the joists, but will not cover them. Some amount of thermal transfer will still occur through the joists themselves.

Unvented roof need r38 in 7 inch rafters - GreenBuildingAdvisor

Nettet12. mai 2011 · The 6' is rafter length on each side of ridge. If a low pitch, 2" is suggested for air space above insulation, steeper pitch, 1" minimum. A ridge vent gives 18 NFVA per ft., each side of a gable roof at soffits needs 9 NFVA per ft.; http://www.airvent.com/homeowner/products/intakeSoffit-specs.shtml pub and people dc

What Size Insulation for 2x8 Floor Joists - SFGATE

Nettet12. apr. 2024 · The cross strapping (that is 2x4/2x6 at 90degrees to the rafters) is there to provide extra insulation space. It does add a bit of structural bridging between adjacent rafters, which might let you reduce the number of collar ties, but it doesn't add support. Nettet11. mai 2024 · Insulation, rated on its ability to reduce thermal transfer, or R-value, comes in rolls and batts that fit between joists. The thicker the insulation, the higher the R-value, says Paragon... NettetWith 2x6 rafters this will give about an R-19 roof, higher if you use thicker solid foam insulation. This gives the best air path, eaves to ridge, but costs more for the labor to nail furring and cut insulation into pieces to fit between rafters. – works well, costs more. You can see a schematic for this approach at left. hotel fear 1978