| Load | Symbol | Given Value (psf) (acting downward) |
| dead load | D | 10 |
| weight of ice | Di | 0 |
| earthquake load | E | 2 |
| load due to fluids | F | 0 |
| flood loads | Fa | 0 |
| load due to sub-surface pressure | H | 0 |
| live load | L | 0 |
| roof live load | Lr | 20 |
| rain load | R | 30 |
| snow load | S | 35 |
| self-straining force | T | 0 |
| wind load | W | 18 |
| wind-on-ice | Wi | 0 |
| ASCE 7 | LRFD Load Combination | Possible Values (psf) | Largest Value (psf) |
| 1 | 1.4(D + F) | 14 | 14 |
| 2 | 1.2(D + F + T) + 1.6(L + H) + 0.5(Lr or S or R) | 22 or 29.5 or 27 | 29.5 |
| 3 | 1.2D + 1.6(Lr or S or R) + (L or 0.8W) | 58.4 or 82.4 or 74.4 | 82.4 |
| 4 | 1.2D + 1.6W + L + 0.5(Lr or S or R) | 50.8 or 58.3 or 55.8 | 58.3 |
| 5 | 1.2D + 1.0E + L + 0.2S | 21 | 21 |
| 6 | 0.9D + 1.6 W + 1.6 H | --A | --A |
| 7 | 0.9D + 1.0E + 1.6 H | --A | --A |
A Combinations 6 and 7 are not applicable because W and E are acting in the same direction (downward) as D. See highlighted paragraph in ASCE 7 section C2.3.
Note a small difference in IBC, where f1 = 1 or 0.5 and f2 = 0.7 or 0.2. See 1605.2.1 for details.
IBC LRFD Load Combination 16-1 1.4(D + F) 16-2 1.2(D + F + T) + 1.6(L + H) + 0.5(Lr or S or R) 16-3 1.2D + 1.6(Lr or S or R) + (f1L or 0.8W) 16-4 1.2D + 1.6W + f1L + 0.5(Lr or S or R) 16-5 1.2D + 1.0E + f1L + f2S 16-6 0.9D + 1.6 W + 1.6 H 16-7 0.9D + 1.0E + 1.6 H