The following is a guide only. Check with your builder or local truss manufacturer. The rows in the chart provide the height (or depth) of the truss and the columns the measurement on-center between each truss.
Example: An 18" high truss placed apart 12 inches on-center, would span 30 feet 5 inches.
| Truss Height | 12" OC | 16" OC | 19.2" OC | 24" OC | |
|---|---|---|---|---|---|
| 12" | 20ft 6in | 20ft 6in | 20ft 1in | 17ft 11in | |
| 14" | 23ft 11in | 23ft 10in | 22ft 1in | 19ft 7in | |
| 16" | 27ft 3in | 26ft 0in | 23ft 9in | 22ft 1in | |
| 18" | 30ft 5in | 27ft 11in | 25ft 4in | 22ft 6in | |
| 20" | 33ft 11in | 29ft 7in | 26ft 10in | 23ft 10in | |
| 22" | 36ft 3in | 31ft 2in | 28ft 3in | 25ft 1in | |
| 24" | 37ft 11in | 32ft 7in | 29ft 7in | 26ft 3in |