2×10 rafter spans (2021 IRC)
Every allowable span the 2021 International Residential Code rafter tables list for a 2×10 in the two ceiling-not-attached load cases — four species, four grades, four spacings — each table cited where it sits.
2021 IRC Table R802.4.1(3) covers ground snow load 30 psf, ceiling not attached to rafters; 2021 IRC Table R802.4.1(1) covers roof live load 20 psf, ceiling not attached to rafters. Both tables are below, in that order.
A 2×10 Southern pine No. 2 rafter at 16-inch centers spans up to 16’10” where the ground snow load is 30 psf and the ceiling is not attached to the rafters (2021 IRC Table R802.4.1(3)). Widen the spacing to 24-inch centers and the same rafter is listed at 13’9”; hold 16-inch centers and switch to Spruce-pine-fir No. 2 and the table lists 18’5”. Under 2021 IRC Table R802.4.1(1) — roof live load 20 psf, ceiling not attached to rafters, 20 psf roof live / 10 psf dead / L/180 — that same Southern pine No. 2 at 16 inches is listed at 20’3”.
2×10 rafters — ground snow load 30 psf, ceiling not attached to rafters
| 2×10 — species and grade | 12" on center | 16" on center | 19.2" on center | 24" on center |
|---|---|---|---|---|
| Douglas fir-larch Select Structural | 26’+ | 24’1” | 22’1” | 19’9” |
| Douglas fir-larch No. 1 | 22’9” | 19’9” | 18’0” | 16’1” |
| Douglas fir-larch No. 2 | 21’7” | 18’9” | 17’1” | 15’3” |
| Douglas fir-larch No. 3 | 16’6” | 14’3” | 13’1” | 11’8” |
| Hem-fir Select Structural | 25’0” | 22’9” | 21’4” | 19’1” |
| Hem-fir No. 1 | 22’6” | 19’6” | 17’9” | 15’11” |
| Hem-fir No. 2 | 21’0” | 18’2” | 16’7” | 14’10” |
| Hem-fir No. 3 | 16’1” | 13’11” | 12’9” | 11’5” |
| Southern pine Select Structural | 26’+ | 23’8” | 22’3” | 20’0” |
| Southern pine No. 1 | 22’3” | 19’3” | 17’7” | 15’9” |
| Southern pine No. 2 | 19’5” | 16’10” | 15’4” | 13’9” |
| Southern pine No. 3 | 15’0” | 13’0” | 11’10” | 10’7” |
| Spruce-pine-fir Select Structural | 24’6” | 22’1” | 20’2” | 18’0” |
| Spruce-pine-fir No. 1 | 21’4” | 18’5” | 16’10” | 15’1” |
| Spruce-pine-fir No. 2 | 21’4” | 18’5” | 16’10” | 15’1” |
| Spruce-pine-fir No. 3 | 16’1” | 13’11” | 12’9” | 11’5” |
2021 IRC Table R802.4.1(3) — ground snow load 30 psf, ceiling not attached to rafters, 30 psf ground snow / 10 psf dead / L/180. table source
2×10 rafters — roof live load 20 psf, ceiling not attached to rafters
| 2×10 — species and grade | 12" on center | 16" on center | 19.2" on center | 24" on center |
|---|---|---|---|---|
| Douglas fir-larch Select Structural | 26’+ | 26’+ | 25’11” | 23’9” |
| Douglas fir-larch No. 1 | 26’+ | 23’9” | 21’8” | 19’5” |
| Douglas fir-larch No. 2 | 26’0” | 22’6” | 20’7” | 18’5” |
| Douglas fir-larch No. 3 | 19’10” | 17’2” | 15’8” | 14’1” |
| Hem-fir Select Structural | 26’+ | 26’+ | 24’6” | 22’9” |
| Hem-fir No. 1 | 26’+ | 23’5” | 21’5” | 19’2” |
| Hem-fir No. 2 | 25’3” | 21’11” | 20’0” | 17’10” |
| Hem-fir No. 3 | 19’5” | 16’9” | 15’4” | 13’8” |
| Southern pine Select Structural | 26’+ | 26’+ | 25’5” | 23’8” |
| Southern pine No. 1 | 26’+ | 23’2” | 21’2” | 18’11” |
| Southern pine No. 2 | 23’5” | 20’3” | 18’6” | 16’6” |
| Southern pine No. 3 | 18’0” | 15’7” | 14’3” | 12’9” |
| Spruce-pine-fir Select Structural | 26’+ | 25’5” | 23’11” | 21’8” |
| Spruce-pine-fir No. 1 | 25’8” | 22’3” | 20’3” | 18’2” |
| Spruce-pine-fir No. 2 | 25’8” | 22’3” | 20’3” | 18’2” |
| Spruce-pine-fir No. 3 | 19’5” | 16’9” | 15’4” | 13’8” |
2021 IRC Table R802.4.1(1) — roof live load 20 psf, ceiling not attached to rafters, 20 psf roof live / 10 psf dead / L/180. table source
What these two rafter tables cover
Both tables above are ceiling-not-attached cases: the ceiling is not fastened to the rafters, and the rafter is checked at L/180. Each number is the span the code table lists for that species, grade, and on-center spacing at the load case stamped at the top of this page.
Where the rafter ties are raised above the wall plates, the allowable rafter span is reduced per 2021 IRC Table R802.4.1(9) (table source). The spans on this page do not carry that reduction, and this page does not restate that table's factors. Point loads, cantilevers beyond the table footnotes, unusual snow loads, or anything else outside the table's stated conditions — that's an engineer's question.
The 2021 IRC R802.4.1 set carries eight rafter span tables. Two are quoted here: 2021 IRC Table R802.4.1(3) (30 psf ground snow / 10 psf dead / L/180, ceiling not attached); 2021 IRC Table R802.4.1(1) (20 psf roof live / 10 psf dead / L/180, ceiling not attached). The other six load variants are not covered at launch: see the code or an engineer.
Other sizes and assemblies
Other rafter sizes: 2×4 rafters · 2×6 rafters · 2×8 rafters · 2×12 rafters
The same 2×10 in other assemblies: 2×10 floor joists · 2×10 ceiling joists · 2×10 deck joists
Common questions
Can 2×10 rafters span 19 feet?
At 16-inch centers, 2×10 Southern pine No. 2 is listed at 16’10” in 2021 IRC Table R802.4.1(3) (30 psf ground snow / 10 psf dead / L/180, ceiling not attached). 26 of the 64 2×10 cells in that table are 19 feet or longer, and the widest spacing among them is 24-inch centers — Hem-fir Select Structural at 24 inches is listed at 19’1”.
Do these 2×10 rafter spans assume a ceiling attached to the rafters?
No. Both tables on this page are the ceiling-not-attached cases — 2021 IRC Table R802.4.1(3) (30 psf ground snow / 10 psf dead / L/180, ceiling not attached) and 2021 IRC Table R802.4.1(1) (20 psf roof live / 10 psf dead / L/180, ceiling not attached) — so the rafter is checked at L/180. The attached-ceiling variants and the heavier ground snow cases are other tables in the 2021 IRC R802.4.1 set and are not covered here: see the code or an engineer.
What do 2×10 rafters span at 24-inch centers?
2021 IRC Table R802.4.1(3) — ground snow load 30 psf, ceiling not attached to rafters — lists 2×10 No. 2 at 24-inch centers as Douglas fir-larch 15’3”, Hem-fir 14’10”, Southern pine 13’9”, Spruce-pine-fir 15’1”. The same four in 2021 IRC Table R802.4.1(1) (roof live load 20 psf, ceiling not attached to rafters): 18’5”, 17’10”, 16’6”, 18’2”.