Spruce-pine-fir (SPF) span tables (2021 IRC)

Spruce-pine-fir SS · No. 1 · No. 2 · No. 3 12 · 16 · 19.2 · 24" on center

Every span the 2021 International Residential Code lists for Spruce-pine-fir, in one place: both floor joist tables, both ceiling joist tables, both rafter tables, and the deck joist table's line for it. A 2×8 Spruce-pine-fir No. 2 floor joist at 16-inch centers spans up to 12’3” under standard residential living-area loads (2021 IRC Table R502.3.1(2)).

40 psf live · 10 dead · L/360

12’3”

Per 2021 IRC Table R502.3.1(2) — residential living areas, 40 psf live / 10 psf dead / L/360.

What the tables list for Spruce-pine-fir

The northern-tier and Canadian white-wood group — spruces, pines and firs graded together and sold as one. It is the light, pale stud and joist stock in most Midwest and Northeast yards.

The American Wood Council publishes its No. 1 and No. 2 as a single combined grade line — Fb = 1,210 psi and E = 1,400,000 psi at 2×8 (AWC Design Values for Joists and Rafters).

Across the 416 cells the six floor, ceiling and rafter tables list for all four species, Spruce-pine-fir lists the longest span of the four outright in none of them, ties for longest in 14, and lists the shortest in 197. Against Douglas fir-larch alone, over the same 416 cells: Douglas fir-larch lists a longer span in 402, the same span in 14, and a shorter span in none of them.

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.

Spruce-pine-fir floor joist spans

Both floor joist tables the code publishes, sliced to Spruce-pine-fir: grade and on-center spacing down the side, lumber size across the top. Each size column links to the page carrying that size across all four species.

Residential sleeping areas — 2021 IRC Table R502.3.1(1)

Grade	Spacing	2×6 floor joist	2×8 floor joist	2×10 floor joist	2×12 floor joist
Select Structural	12" on center	11’7”	15’3”	19’5”	23’7”
	16" on center	10’6”	13’10”	17’8”	21’6”
	19.2" on center	9’10”	13’0”	16’7”	20’2”
	24" on center	9’2”	12’1”	15’5”	18’9”
No. 1	12" on center	11’3”	14’11”	19’0”	23’0”
	16" on center	10’3”	13’6”	17’2”	19’11”
	19.2" on center	9’8”	12’9”	15’8”	18’3”
	24" on center	8’11”	11’6”	14’1”	16’3”
No. 2	12" on center	11’3”	14’11”	19’0”	23’0”
	16" on center	10’3”	13’6”	17’2”	19’11”
	19.2" on center	9’8”	12’9”	15’8”	18’3”
	24" on center	8’11”	11’6”	14’1”	16’3”
No. 3	12" on center	9’8”	12’4”	15’0”	17’5”
	16" on center	8’5”	10’8”	13’0”	15’1”
	19.2" on center	7’8”	9’9”	11’10”	13’9”
	24" on center	6’10”	8’8”	10’7”	12’4”

2021 IRC Table R502.3.1(1) — residential sleeping areas, 30 psf live / 10 psf dead / L/360, Spruce-pine-fir. table source

Residential living areas — 2021 IRC Table R502.3.1(2)

Grade	Spacing	2×6 floor joist	2×8 floor joist	2×10 floor joist	2×12 floor joist
Select Structural	12" on center	10’6”	13’10”	17’8”	21’6”
	16" on center	9’6”	12’7”	16’0”	19’6”
	19.2" on center	9’0”	11’10”	15’1”	18’4”
	24" on center	8’4”	11’0”	14’0”	17’0”
No. 1	12" on center	10’3”	13’6”	17’3”	20’7”
	16" on center	9’4”	12’3”	15’5”	17’10”
	19.2" on center	8’9”	11’6”	14’1”	16’3”
	24" on center	8’1”	10’3”	12’7”	14’7”
No. 2	12" on center	10’3”	13’6”	17’3”	20’7”
	16" on center	9’4”	12’3”	15’5”	17’10”
	19.2" on center	8’9”	11’6”	14’1”	16’3”
	24" on center	8’1”	10’3”	12’7”	14’7”
No. 3	12" on center	8’8”	11’0”	13’5”	15’7”
	16" on center	7’6”	9’6”	11’8”	13’6”
	19.2" on center	6’10”	8’8”	10’7”	12’4”
	24" on center	6’2”	7’9”	9’6”	11’0”

2021 IRC Table R502.3.1(2) — residential living areas, 40 psf live / 10 psf dead / L/360, Spruce-pine-fir. table source

The two tables differ in one thing: the live load the floor is checked against. Both carry the same 10 psf dead load and the same L/360 deflection limit, so the lighter live load is what lets the sleeping-area table list a longer span for the same stick of lumber. Both in full, all four species: the 2021 IRC floor joist span tables.

Spruce-pine-fir ceiling joist spans

Both ceiling joist tables, sliced to Spruce-pine-fir. These are attic floors, not living-area floors: the load cases are lighter and deflection is held to L/240, which is why so many cells run past the end of the table.

Uninhabitable attics without storage — 2021 IRC Table R802.5.1(1)

Grade	Spacing	2×4 ceiling joist	2×6 ceiling joist	2×8 ceiling joist	2×10 ceiling joist
Select Structural	12" on center	12’2”	19’1”	25’2”	26’+
	16" on center	11’0”	17’4”	22’10”	26’+
	19.2" on center	10’4”	16’4”	21’6”	26’+
	24" on center	9’8”	15’2”	19’11”	25’5”
No. 1	12" on center	11’10”	18’8”	24’7”	26’+
	16" on center	10’9”	16’11”	22’4”	26’+
	19.2" on center	10’2”	15’11”	21’0”	25’8”
	24" on center	9’5”	14’9”	18’9”	22’11”
No. 2	12" on center	11’10”	18’8”	24’7”	26’+
	16" on center	10’9”	16’11”	22’4”	26’+
	19.2" on center	10’2”	15’11”	21’0”	25’8”
	24" on center	9’5”	14’9”	18’9”	22’11”
No. 3	12" on center	10’10”	15’10”	20’1”	24’6”
	16" on center	9’5”	13’9”	17’5”	21’3”
	19.2" on center	8’7”	12’6”	15’10”	19’5”
	24" on center	7’8”	11’2”	14’2”	17’4”

2021 IRC Table R802.5.1(1) — uninhabitable attics without storage, 10 psf live / 5 psf dead / L/240, Spruce-pine-fir. table source

Uninhabitable attics with limited storage — 2021 IRC Table R802.5.1(2)

Grade	Spacing	2×4 ceiling joist	2×6 ceiling joist	2×8 ceiling joist	2×10 ceiling joist
Select Structural	12" on center	9’8”	15’2”	19’11”	25’5”
	16" on center	8’9”	13’9”	18’1”	23’1”
	19.2" on center	8’3”	12’11”	17’1”	21’8”
	24" on center	7’8”	12’0”	15’10”	19’5”
No. 1	12" on center	9’5”	14’9”	18’9”	22’11”
	16" on center	8’7”	12’10”	16’3”	19’10”
	19.2" on center	8’0”	11’9”	14’10”	18’2”
	24" on center	7’2”	10’6”	13’3”	16’3”
No. 2	12" on center	9’5”	14’9”	18’9”	22’11”
	16" on center	8’7”	12’10”	16’3”	19’10”
	19.2" on center	8’0”	11’9”	14’10”	18’2”
	24" on center	7’2”	10’6”	13’3”	16’3”
No. 3	12" on center	7’8”	11’2”	14’2”	17’4”
	16" on center	6’8”	9’8”	12’4”	15’0”
	19.2" on center	6’1”	8’10”	11’3”	13’8”
	24" on center	5’5”	7’11”	10’0”	12’3”

2021 IRC Table R802.5.1(2) — uninhabitable attics with limited storage, 20 psf live / 10 psf dead / L/240, Spruce-pine-fir. table source

Both in full, all four species: the 2021 IRC ceiling joist span tables.

Spruce-pine-fir rafter spans

Two of the eight rafter span tables in the 2021 IRC R802.4.1 set, sliced to Spruce-pine-fir — both of them ceiling-not-attached cases, at the L/180 deflection limit those tables state. The other six load variants in that set are not covered on this site.

Roof live load 20 psf, ceiling not attached to rafters — 2021 IRC Table R802.4.1(1)

Grade	Spacing	2×4 rafter	2×6 rafter	2×8 rafter	2×10 rafter	2×12 rafter
Select Structural	12" on center	10’7”	16’8”	21’11”	26’+	26’+
	16" on center	9’8”	15’2”	19’11”	25’5”	26’+
	19.2" on center	9’1”	14’3”	18’9”	23’11”	26’+
	24" on center	8’5”	13’3”	17’5”	21’8”	25’2”
No. 1	12" on center	10’4”	16’3”	21’0”	25’8”	26’+
	16" on center	9’5”	14’4”	18’2”	22’3”	25’9”
	19.2" on center	8’10”	13’1”	16’7”	20’3”	23’6”
	24" on center	8’0”	11’9”	14’10”	18’2”	21’0”
No. 2	12" on center	10’4”	16’3”	21’0”	25’8”	26’+
	16" on center	9’5”	14’4”	18’2”	22’3”	25’9”
	19.2" on center	8’10”	13’1”	16’7”	20’3”	23’6”
	24" on center	8’0”	11’9”	14’10”	18’2”	21’0”
No. 3	12" on center	8’7”	12’6”	15’10”	19’5”	22’6”
	16" on center	7’5”	10’10”	13’9”	16’9”	19’6”
	19.2" on center	6’9”	9’11”	12’7”	15’4”	17’9”
	24" on center	6’1”	8’10”	11’3”	13’8”	15’11”

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, Spruce-pine-fir. table source

Ground snow load 30 psf, ceiling not attached to rafters — 2021 IRC Table R802.4.1(3)

Grade	Spacing	2×4 rafter	2×6 rafter	2×8 rafter	2×10 rafter	2×12 rafter
Select Structural	12" on center	9’3”	14’7”	19’2”	24’6”	26’+
	16" on center	8’5”	13’3”	17’5”	22’1”	25’7”
	19.2" on center	7’11”	12’5”	16’5”	20’2”	23’4”
	24" on center	7’4”	11’7”	14’9”	18’0”	20’11”
No. 1	12" on center	9’1”	13’9”	17’5”	21’4”	24’8”
	16" on center	8’2”	11’11”	15’1”	18’5”	21’5”
	19.2" on center	7’5”	10’11”	13’9”	16’10”	19’6”
	24" on center	6’8”	9’9”	12’4”	15’1”	17’6”
No. 2	12" on center	9’1”	13’9”	17’5”	21’4”	24’8”
	16" on center	8’2”	11’11”	15’1”	18’5”	21’5”
	19.2" on center	7’5”	10’11”	13’9”	16’10”	19’6”
	24" on center	6’8”	9’9”	12’4”	15’1”	17’6”
No. 3	12" on center	7’1”	10’5”	13’2”	16’1”	18’8”
	16" on center	6’2”	9’0”	11’5”	13’11”	16’2”
	19.2" on center	5’7”	8’3”	10’5”	12’9”	14’9”
	24" on center	5’0”	7’4”	9’4”	11’5”	13’2”

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, Spruce-pine-fir. table source

Both in full, all four species, plus the raised-tie note: the 2021 IRC rafter span tables.

Spruce-pine-fir deck joist spans

Deck joists are quoted from their own table, not the floor table: 2021 IRC Table R507.6 carries a 10 psf dead load, No. 2 grade, the wet service factor for lumber that gets wet, and deflection held to L/360 — and it runs ground snow load cases a floor table never sees. This is the table pressure-treated deck framing is read from.

Load case	Joist size	12" on center	16" on center	24" on center
40 psf live load	2×6 deck joists	9’6”	8’4”	6’10”
	2×8 deck joists	12’6”	11’1”	9’1”
	2×10 deck joists	15’8”	13’7”	11’1”
	2×12 deck joists	18’0”	15’9”	12’10”
50 psf ground snow load	2×6 deck joists	8’10”	8’0”	6’8”
	2×8 deck joists	11’7”	10’7”	8’11”
	2×10 deck joists	14’10”	13’3”	10’10”
	2×12 deck joists	17’9”	15’5”	12’7”
60 psf ground snow load	2×6 deck joists	8’4”	7’6”	6’2”
	2×8 deck joists	10’11”	9’11”	8’3”
	2×10 deck joists	13’11”	12’4”	10’0”
	2×12 deck joists	16’6”	14’3”	11’8”
70 psf ground snow load	2×6 deck joists	7’11”	7’1”	5’9”
	2×8 deck joists	10’5”	9’5”	7’8”
	2×10 deck joists	13’3”	11’6”	9’5”
	2×12 deck joists	15’5”	13’4”	10’11”

2021 IRC Table R507.6 — 40 psf live load, 50 psf ground snow load, 60 psf ground snow load, 70 psf ground snow load; 10 psf dead load, No. 2 grade, wet service factor included, deflection L/360, Douglas fir-larch / Hem-fir / Spruce-pine-fir. table source

The same table's cantilever limits — the maximum overhang past the beam, against each joist back span — are on the 2021 IRC deck joist span tables. The beam those joists land on is a different table again: deck beam spans.

Spruce-pine-fir grades, and what the stamp says

Species is only half the row. Every species is graded, and the grade is a visual sort — how many knots, how big, where they fall, how straight the grain runs. Tighter sort, longer listed span. Taking a 2×8 Spruce-pine-fir at 16-inch centers straight down the grade column of 2021 IRC Table R502.3.1(2):

Select Structural — 12’7” — the tightest sort, and the longest span the table lists for this species and size.
No. 1 — 12’3” — a step down in knot size and grain slope.
No. 2 — 12’3” — the everyday framing grade, and the grade the R507 deck tables are listed for.
No. 3 — 9’6” — the loosest sort of the four, and the shortest listed span.

Every No. 1 cell for Spruce-pine-fir in these six tables matches its No. 2 cell — all 104 of them — so the two grades read the same span at every size, spacing and load case on this page.

The number that applies is the one stamped on the piece. A grade stamp names the grading agency, the species or species combination, the grade, and the moisture condition at surfacing — and that stamp, not the invoice or the bin label, is what an inspector reads.

Headers and girders are not split by species

2021 IRC Tables R602.7(1) and R602.7(2) list one set of spans for Douglas fir-larch, hem-fir, Southern pine and spruce-pine-fir together, so a Spruce-pine-fir header is read off the same row as any of the other three, with the same jack-stud count at each end. Those tables — exterior bearing walls, and the interior bearing walls and floor girders of R602.7(2) — are on the header and girder spans page.

Common questions

How far can a 2×8 Spruce-pine-fir floor joist span?

2021 IRC Table R502.3.1(2) lists a 2×8 Spruce-pine-fir No. 2 floor joist under residential living-area loads at 13’6” at 12-inch centers, 12’3” at 16-inch centers, 11’6” at 19.2-inch centers, 10’3” at 24-inch centers. Change the grade, the size, the load case or the assembly and you are reading a different cell — every one of them for this species is on this page.

Which spans farther, Spruce-pine-fir or Douglas fir-larch?

Against Douglas fir-larch alone, over the same 416 cells: Douglas fir-larch lists a longer span in 402, the same span in 14, and a shorter span in none of them. Across the 416 cells the six floor, ceiling and rafter tables list for all four species, Spruce-pine-fir lists the longest span of the four outright in none of them, ties for longest in 14, and lists the shortest in 197. Read the row for the species stamped on the lumber you actually have — whether a substitution against an approved plan is acceptable is your building department's call, not the table's.

Which deck joist row does Spruce-pine-fir use?

2021 IRC Table R507.6 does not split these three. Douglas fir-larch, hem-fir and spruce-pine-fir share one line, and the deck spans below are that line — the same numbers for all three of them. Southern pine sits on its own line above it and lists a longer span in 47 of the 48 cells the two lines share. A 2×8 at 16-inch centers under the 40 psf live load case is listed at 11’1” on that line. The deck table also carries the cantilever limits, on the 2021 IRC Table R507.6 page.

Is there a separate header span for Spruce-pine-fir?

No. 2021 IRC Tables R602.7(1) and R602.7(2) list one set of header and girder spans for Douglas fir-larch, hem-fir, Southern pine and spruce-pine-fir together, so a Spruce-pine-fir header is read off the same row as any of the other three, at the same jack-stud count. 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 other three species

Same tables, one species at a time: Southern pine spans · Douglas fir-larch spans · Hem-fir spans

All four side by side, and why the same 2×8 lists a different span in each row: the species comparison.

Local codes amend these tables and your inspector has the final word — confirm with your building department.