WAC 51-11C-610211. Table A102.1 — Default U-factors for ceilings

Table A102.1 Default U-factors for Ceilings Standard Frame Advanced Frame Ceilings Below Vented Attics Flat Baffled R-19 0.049 0.047 R-30 0.036 0.032 R-38 0.031 0.026 R-49 0.027 0.020 R-60 0.025 0.017 Scissors Truss R-30 (4/12 roof pitch) 0.043 0.031 R-38 (4/12 roof pitch) 0.040 0.025 R-49 (4/12 roof pitch) 0.038 0.020 R-30 (5/12 roof pitch) 0.039 0.032 R-38 (5/12 roof pitch) 0.035 0.026 R-49 (5/12 roof pitch) 0.032 0.020 Vaulted Ceilings 16" O.C. 24" O.C. Vented R-19 2x10 joist 0.049 0.048 R-30 2x12 joist 0.034 0.033 R-38 2x14 joist 0.027 0.027 Unvented R-30 2x10 joist 0.034 0.033 R-38 2x12 joist 0.029 0.027 R-21 + R-21 2x12 joist 0.026 0.025 Roof Deck 4 x Beams, 48" O.C. R-12.5 2" Rigid insulation 0.064 R-21.9 3.5" Rigid insulation 0.040 R-37.5 6" Rigid insulation 0.025 R-50 8" Rigid insulation 0.019 Standard Frame Advanced Frame Ceilings Below Vented Attics Flat Baffled R-19 0.049 0.047 R-30 0.036 0.032 R-38 0.031 0.026 R-49 0.027 0.020 R-60 0.025 0.017 Scissors Truss R-30 (4/12 roof pitch) 0.043 0.031 R-38 (4/12 roof pitch) 0.040 0.025 R-49 (4/12 roof pitch) 0.038 0.020 R-30 (5/12 roof pitch) 0.039 0.032 R-38 (5/12 roof pitch) 0.035 0.026 R-49 (5/12 roof pitch) 0.032 0.020 Vaulted Ceilings 16" O.C. 24" O.C. Vented R-19 2x10 joist 0.049 0.048 R-30 2x12 joist 0.034 0.033 R-38 2x14 joist 0.027 0.027 Unvented R-30 2x10 joist 0.034 0.033 R-38 2x12 joist 0.029 0.027 R-21 + R-21 2x12 joist 0.026 0.025 Roof Deck 4 x Beams, 48" O.C. R-12.5 2" Rigid insulation 0.064 R-21.9 3.5" Rigid insulation 0.040 R-37.5 6" Rigid insulation 0.025 R-50 8" Rigid insulation 0.019