Find the maximum spans for ceiling joists according to the 2018 International Residential Code using the most common types of lumber with these simplified span tables. These span tables are for 16″ o.c. applications using southern pine. Plain ceilings are sized at 10 lb loads, while the ceilings with storage are sized for 20 lb loads. For all other uses and materials click here for the reference in the code book.
2 x 6 Ceiling Joists
Southern Pine | Ceiling | Ceiling with Storage | |
| Number 1 | 17′ 8″ | 14′ | |
| Number 2 | 16′ 11″ | 12′ | |
| Number 3 | 12′ 11″ | 9′ 2″ | |
| SS | 18′ 5″ | 14′ 7″ | |
2 x 8 Ceiling Joists
Southern Pine | Ceiling | Ceiling with Storage | |
| Number 1 | 23′ 10″ | 17′ 9″ | |
| Number 2 | 21′ 7″ | 15′ 3″ | |
| Number 3 | 16′ 3″ | 11′ 6″ | |
| SS | 24′ 3″ | 19′ 3″ | |
2 x 10 Ceiling Joists
Southern Pine | Ceiling | Ceiling with Storage | |
| Number 1 | over 26′ | 20′ 9″ | |
| Number 2 | 25′ 7″ | 18′ 1″ | |
| Number 3 | 19′ 9″ | 14′ | |
| SS | over 26′ | 24′ 7″ | |