TABLE OF CONTENTS Weights are for Douglas Fir-Larch lumber (S4S) used at an equilibrium moisture content of 15 percent (the maximum found in most covered structures). The unit weight of Douglas Fir-Larch equals or exceeds the unit weight of most softwood species, and the dead loads given below are conservative for most designs.
| Spacing | ||||||
|---|---|---|---|---|---|---|
| 12 in. o.c. | 16 in. o.c. | 24 in. o.c. | ||||
| Nominal size | Weight, psf | Board feet* per ft 2 | Weight, psf | Board feet* per ft 2 | Weight, psf | Board feet* per ft 2 |
| 2 3 | 0.9 | 0.50 | 0.7 | 0.38 | 0.4 | 0.25 |
| 2 4 | 1.2 | 0.67 | 0.9 | 0.50 | 0.6 | 0.34 |
| 2 6 | 1.9 | 1.00 | 1.4 | 0.75 | 1.0 | 0.5 |
| 2 8 | 2.5 | 1.33 | 1.9 | 1.00 | 1.3 | 0.67 |
| 2 10 | 3.2 | 1.67 | 2.4 | 1.25 | 1.6 | 0.84 |
| 2 12 | 3.9 | 2.00 | 2.9 | 1.50 | 2.0 | 1.00 |
| 3 6 | 3.2 | 1.50 | 2.4 | 1.13 | 1.6 | 0.75 |
| 3 8 | 4.2 | 2.00 | 3.1 | 1.50 | 2.1 | 1.00 |
| 3 10 | 5.4 | 2.50 | 4.0 | 1.88 | 2.7 | 1.25 |
| 3 12 | 6.6 | 3.00 | 4.9 | 2.25 | 3.3 | 1.50 |
| 3 14 | 7.7 | 3.50 | 5.8 | 2.63 | 3.9 | 1.75 |
| 4 8 | 5.9 | 2.67 | 4.4 | 2.00 | 3.0 | 1.34 |
| 4 10 | 7.5 | 3.33 | 5.7 | 2.50 | 3.8 | 1.67 |
| 4 12 | 9.2 | 4.00 | 6.9 | 3.00 | 4.6 | 2.00 |
| 4 14 | 11.0 | 4.67 | 8.1 | 3.50 | 5.4 | 2.34 |
| 4 16 | 12.4 | 5.33 | 9.3 | 4.00 | 6.2 | 2.67 |
| *Lumber is ordered and priced by the board foot. A board foot is a volume of lumber corresponding to 1 in. |
