Design Specifications:
Slopes Less Than 4:12, Lightweight Roofing
Dead Load = 10 psf, Live Load = 20 psf (Residential)
Douglas Fir - Larch Framing, Deflection of L/240 maximum.
| Size of Roof Rafters (inches) | Spacing of Roof Rafters (inches) | No. 2 Douglas Fir | No. 1 Douglas Fir | ||
| Supporting a ceiling | Not supporting a celing (-2.5#) | Supporting a ceiling | Not supporting a ceiling (-2.5#) | ||
| 2 x 6 | 12 | 13'-6" | 13'-10" | 13'-9" | 14'-2" |
| 16 | 12'-3" | 12'-7" | 12'-6" | 12'-10" | |
| 24 | 10'-8" | 11'-0" | 10'-11" | 11'-3" | |
| 2 x 8 | 12 | 17'-9" | 18'-2" | 18'-2" | 18'-8" |
| 16 | 16'-2" | 16'-7" | 16'-6" | 16'-11" | |
| 24 | 13'-10" | 14'-5" | 14'-5" | 14'-10" | |
| 2 x 10 | 12 | 22'-8" | 23'-4" | 23'-2" | 23'-10" |
| 16 | 20'-7" | 21'-3" | 21'-0" | 21'-8" | |
| 24 | 16'-10" | 17'-8" | 18'-0" | 18'-10" | |
Design Specifications:
Slopes Of 4:12 Or Greater, Lightweight Roofing
Dead Load = 10 psf, Live Load = 16 psf (Residential)
Douglas Fir - Larch Framing, Deflection of L/240 maximum.
| Size of Roof Rafters (inches) | Spacing of Roof Rafters (inches) | Construction Grade Douglas Fir | No.2 Douglas Fir | No.1 Douglas Fir |
| 2 x 4 | 12 | 8'-7" | ||
| 16 | 7'-9" | |||
| 24 | 6'-10" | |||
| 2 x 6 | 12 | 14'-2" | 14'-5" | |
| 16 | 12'-10" | 13'-1" | ||
| 24 | 11'-3" | 11'-5" | ||
| 2 x 8 | 12 | 18'-8" | 19'-0" | |
| 16 | 16'-11" | 17'-3" | ||
| 24 | 14'-9" | 15'-1" | ||
| 2 x 10 | 12 | 23'-8" | 24'-3" | |
| 16 | 21'-7" | 22'-1" | ||
| 24 | 18'-2" | 19'-3" |
Design Specifications:
Slopes Less Than 4:12, Lightweight Roofing
Dead Load = 15 psf, Live Load = 20 psf (Residential)
Douglas Fir - Larch Framing, Deflection of L/240 maximum.
| Size of Roof Rafters (inches) | Spacing of Roof Rafters (inches) | No. 2 Douglas Fir | No. 1 Douglas Fir | ||
| Supporting a ceiling | Not supporting a celing (-2.5#) | Supporting a ceiling | Not supporting a ceiling (-2.5#) | ||
| 2 x 6 | 12 | 12'-9" | 13'-1" | 13'-1" | 13'-5" |
| 16 | 11'-7" | 11'-11" | 11'-10" | 12'-2" | |
| 24 | 10'-1" | 10'-5" | 10'-3" | 10'-7" | |
| 2 x 8 | 12 | 16'-10" | 17'-4" | 17'-3" | 17'-8" |
| 16 | 15'-4" | 15'-9" | 15'-8" | 16'-0" | |
| 24 | 12'-9" | 13'-2" | 13'-7" | 14'-0" | |
| 2 x 10 | 12 | 21'-7" | 22'-1" | 22'-0" | 22'-6" |
| 16 | 19'-2" | 19'-10" | 20'-0" | 20'-6" | |
| 24 | 15'-8" | 16'-3" | 16'-8" | 17'-4" | |
Design Specifications:
Slopes Of 4:12 Or Greater, Lightweight Roofing
Dead Load = 15 psf, Live Load = 16 psf (Residential)
Douglas Fir - Larch Framing, Deflection of L/240 maximum.
| Size of Roof Rafters (inches) | Spacing of Roof Rafters (inches) | Construction Grade Douglas Fir | No.2 Douglas Fir | No.1 Douglas Fir |
| 2 x 4 | 12 | 8'-1" | ||
| 16 | 7'-4" | |||
| 24 | 6'-5" | |||
| 2 x 6 | 12 | 13'-4" | 13'-7" | |
| 16 | 12'-1" | 12'-4" | ||
| 24 | 10'-6" | 10'-7" | ||
| 2 x 8 | 12 | 17'-6" | 17'-11" | |
| 16 | 16'-0" | 16'-4" | ||
| 24 | 13'-7" | 14'-3" | ||
| 2 x 10 | 12 | 22'-5" | 22'-11" | |
| 16 | 20'-4" | 20'-9" | ||
| 24 | 16'-7" | 17'-9" |