
Depending on the desired depth (height) and spacing, floor trusses may clear-span rooms of 30 feet or more.
The ability to top chord bear over a beam in mid-span allows very large basement rooms with unbroken ceilings.

| Depth (Inches) | 24'' O.C. | 19.2'' O.C. | 16'' O.C. | 12'' O.C. |
| 12 | 16'-4'' | 18'-8'' | 20'-6'' | 20'-6'' |
| 13 | 17'-2'' | 19'-6'' | 21'-8'' | 22'-2'' |
| 14 | 17'-11'' | 20'-4'' | 22'-7'' | 23'-11' |
| 15 | 18'-7'' | 21'-2'' | 23'-6'' | 25'-7'' |
| 16 | 19'-3'' | 21'-11'' | 24'-4'' | 27'-3'' |
| 17 | 19'-11'' | 22'-8'' | 25'-2'' | 29' |
| 18 | 20'-6'' | 23'-5'' | 25'-11'' | 30'-5'' |
| 20 | 21'-9'' | 24'-9'' | 27'-6'' | 32'-3'' |
| 22 | 22'-11'' | 26'-1'' | 28'-11'' | 33'-11'' |
| 24 | 24' | 27'-4'' | 30'-4'' | 35'-6'' |