These rafter span tables provide the best reference to quickly and easily determine the maximum span for all grades of southern pine according to the 2018 International Residential Code. These eight tables are based on 16″ o.c. applications according to the 2018 International Residential Code. The focus is 20 PSF live load. For all other situations click here for quick reference in the code book.
2 x 6 Rafter Span
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 15′ 6″ | 13′ 7″ |
| Number 2 | 13′ 6″ | 11′ 8″ |
| Number 3 | 10′ 2″ | 8′ 10″ |
| SS | 16′ 1″ | 16′ 1″ |
2 x 8 Rafter Span
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 19′ 10″ | 17′ 2″ |
| Number 2 | 17′ 1″ | 14′ 9″ |
| Number 3 | 12′ 10″ | 11′ 2″ |
| SS | 21′ 2″ | 21′ 2″ |
2 x 10 Rafter Span
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 23′ 2″ | 20′ 1″ |
| Number 2 | 17′ 1″ | 14′ 9″ |
| Number 3 | 12′ 10″ | 11′ 2″ |
| SS | 26′ + | 25′ 7″ |
2 x 12 Rafter Span
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 26′ + | 26′ + |
| Number 2 | 23′ 10″ | 20′ 8″ |
| Number 3 | 18′ 6″ | 16′ |
| SS | 26′ + | 26′ + |
2 x 6 Rafter Span with Ceiling
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 14′ 1″ | 13′ 7″ |
| Number 2 | 13′ 5″ | 11′ 8″ |
| Number 3 | 10′ 2″ | 8′ 10″ |
| SS | 14′ 7″ | 14′ 7″ |
2 x 8 Rafter Span with Ceiling
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 18′ 6″ | 17′ 2″ |
| Number 2 | 17′ 1″ | 14′ 9″ |
| Number 3 | 12′ 10″ | 11′ 2″ |
| SS | 19′ 3″ | 19′ 3″ |
2 x 10 Rafter Span with Ceiling
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 23′ 2″ | 22′ 1″ |
| Number 2 | 20′ 3″ | 17′ 6″ |
| Number 3 | 15′ 7″ | 13′ 6″ |
| SS | 24′ 7″ | 24′ 7″ |
2 x 12 Rafter Span with Ceiling
Southern Pine | 10 PSF dead | 20 PSF dead |
| Number 1 | 26′ + | 23′ 10″ |
| Number 2 | 23′ 10″ | 20′ 8″ |
| Number 3 | 18′ 6″ | 16′ |
| SS | 26′ + | 26′ + |