Span tables

30 psf live · 10 psf dead · L/180

Rafters — 30 psf Ground Snow Load

Sloped roof rafters where the ceiling is not attached to the rafters (30 psf ground snow load). Rafter spans are the horizontal projection. A blank cell means the span exceeds the maximum shown in the source table for that size.

Source: International Residential Code (IRC), 2018Table R802.4.1(3) — Rafter Spans, 30 psf Ground Snow Load (ceiling not attached, L/180). Published by International Code Council.

SpacingSpecies & grade2x42x62x82x102x12
12″ o.c.Douglas Fir-Larch · SS10′-0″15′-9″20′-9″
12″ o.c.Douglas Fir-Larch · #19′-8″14′-9″18′-8″22′-9″
12″ o.c.Douglas Fir-Larch · #29′-6″14′-0″17′-8″21′-7″25′-1″
12″ o.c.Douglas Fir-Larch · #3
12″ o.c.Hem-Fir · SS9′-6″14′-10″19′-7″25′-0″
12″ o.c.Hem-Fir · #19′-3″14′-6″18′-5″22′-6″26′-0″
12″ o.c.Hem-Fir · #28′-10″13′-7″17′-2″21′-0″24′-4″
12″ o.c.Hem-Fir · #3
12″ o.c.Spruce-Pine-Fir · SS9′-3″14′-7″19′-2″24′-6″
12″ o.c.Spruce-Pine-Fir · #19′-1″13′-9″17′-5″21′-4″24′-8″
12″ o.c.Spruce-Pine-Fir · #29′-1″13′-9″17′-5″21′-4″24′-8″
12″ o.c.Spruce-Pine-Fir · #3
12″ o.c.Southern Pine · SS9′-10″15′-6″20′-5″
12″ o.c.Southern Pine · #19′-6″14′-10″19′-0″22′-3″
12″ o.c.Southern Pine · #28′-7″12′-11″16′-4″19′-5″22′-10″
12″ o.c.Southern Pine · #3
16″ o.c.Douglas Fir-Larch · SS9′-1″14′-4″18′-10″24′-1″
16″ o.c.Douglas Fir-Larch · #18′-9″12′-9″16′-2″19′-9″22′-10″
16″ o.c.Douglas Fir-Larch · #28′-3″12′-1″15′-4″18′-9″21′-8″
16″ o.c.Douglas Fir-Larch · #3
16″ o.c.Hem-Fir · SS8′-7″13′-6″17′-10″22′-9″
16″ o.c.Hem-Fir · #18′-5″12′-7″15′-11″19′-6″22′-7″
16″ o.c.Hem-Fir · #28′-0″11′-9″14′-11″18′-2″21′-1″
16″ o.c.Hem-Fir · #3
16″ o.c.Spruce-Pine-Fir · SS8′-5″13′-3″17′-5″22′-1″25′-7″
16″ o.c.Spruce-Pine-Fir · #18′-2″11′-11″15′-1″18′-5″21′-5″
16″ o.c.Spruce-Pine-Fir · #28′-2″11′-11″15′-1″18′-5″21′-5″
16″ o.c.Spruce-Pine-Fir · #3
16″ o.c.Southern Pine · SS8′-11″14′-1″18′-6″23′-8″
16″ o.c.Southern Pine · #18′-7″13′-0″16′-6″19′-3″22′-10″
16″ o.c.Southern Pine · #27′-6″11′-2″14′-2″16′-10″19′-10″
16″ o.c.Southern Pine · #3
19.2″ o.c.Douglas Fir-Larch · SS8′-7″13′-6″17′-9″22′-1″25′-7″
19.2″ o.c.Douglas Fir-Larch · #17′-11″11′-8″14′-9″18′-0″20′-11″
19.2″ o.c.Douglas Fir-Larch · #27′-7″11′-0″14′-0″17′-1″19′-10″
19.2″ o.c.Douglas Fir-Larch · #3
19.2″ o.c.Hem-Fir · SS8′-1″12′-9″16′-9″21′-4″24′-8″
19.2″ o.c.Hem-Fir · #17′-10″11′-6″14′-7″17′-9″20′-7″
19.2″ o.c.Hem-Fir · #27′-4″10′-9″13′-7″16′-7″19′-3″
19.2″ o.c.Hem-Fir · #3
19.2″ o.c.Spruce-Pine-Fir · SS7′-11″12′-5″16′-5″20′-2″23′-4″
19.2″ o.c.Spruce-Pine-Fir · #17′-5″10′-11″13′-9″16′-10″19′-6″
19.2″ o.c.Spruce-Pine-Fir · #27′-5″10′-11″13′-9″16′-10″19′-6″
19.2″ o.c.Spruce-Pine-Fir · #3
19.2″ o.c.Southern Pine · SS8′-5″13′-3″17′-5″22′-3″
19.2″ o.c.Southern Pine · #18′-0″11′-10″15′-1″17′-7″20′-11″
19.2″ o.c.Southern Pine · #26′-10″10′-2″12′-11″15′-4″18′-1″
19.2″ o.c.Southern Pine · #3
24″ o.c.Douglas Fir-Larch · SS8′-0″12′-6″16′-2″19′-9″22′-10″
24″ o.c.Douglas Fir-Larch · #17′-1″10′-5″13′-2″16′-1″18′-8″
24″ o.c.Douglas Fir-Larch · #26′-9″9′-10″12′-6″15′-3″17′-9″
24″ o.c.Douglas Fir-Larch · #3
24″ o.c.Hem-Fir · SS7′-6″11′-10″15′-7″19′-1″22′-1″
24″ o.c.Hem-Fir · #17′-0″10′-3″13′-0″15′-11″18′-5″
24″ o.c.Hem-Fir · #26′-7″9′-7″12′-2″14′-10″17′-3″
24″ o.c.Hem-Fir · #3
24″ o.c.Spruce-Pine-Fir · SS7′-4″11′-7″14′-9″18′-0″20′-11″
24″ o.c.Spruce-Pine-Fir · #16′-8″9′-9″12′-4″15′-1″17′-6″
24″ o.c.Spruce-Pine-Fir · #26′-8″9′-9″12′-4″15′-1″17′-6″
24″ o.c.Spruce-Pine-Fir · #3
24″ o.c.Southern Pine · SS7′-10″12′-3″16′-2″20′-0″23′-7″
24″ o.c.Southern Pine · #17′-1″10′-7″13′-5″15′-9″18′-8″
24″ o.c.Southern Pine · #26′-1″9′-2″11′-7″13′-9″16′-2″
24″ o.c.Southern Pine · #3
Rafters — 30 psf Ground Snow Load. Live load 30 psf, dead load 10 psf, deflection limit L/180. Spans in feet-inches; “—” means the source leaves that cell blank.

Per-combination pages

Jump to a specific span

2x4 Douglas Fir-Larch · 12″ o.c.2x4 Douglas Fir-Larch · 16″ o.c.2x4 Douglas Fir-Larch · 19.2″ o.c.2x4 Douglas Fir-Larch · 24″ o.c.2x6 Douglas Fir-Larch · 12″ o.c.2x6 Douglas Fir-Larch · 16″ o.c.2x6 Douglas Fir-Larch · 19.2″ o.c.2x6 Douglas Fir-Larch · 24″ o.c.2x8 Douglas Fir-Larch · 12″ o.c.2x8 Douglas Fir-Larch · 16″ o.c.2x8 Douglas Fir-Larch · 19.2″ o.c.2x8 Douglas Fir-Larch · 24″ o.c.2x10 Douglas Fir-Larch · 12″ o.c.2x10 Douglas Fir-Larch · 16″ o.c.2x10 Douglas Fir-Larch · 19.2″ o.c.2x10 Douglas Fir-Larch · 24″ o.c.2x12 Douglas Fir-Larch · 12″ o.c.2x12 Douglas Fir-Larch · 16″ o.c.2x12 Douglas Fir-Larch · 19.2″ o.c.2x12 Douglas Fir-Larch · 24″ o.c.2x4 Hem-Fir · 12″ o.c.2x4 Hem-Fir · 16″ o.c.2x4 Hem-Fir · 19.2″ o.c.2x4 Hem-Fir · 24″ o.c.2x6 Hem-Fir · 12″ o.c.2x6 Hem-Fir · 16″ o.c.2x6 Hem-Fir · 19.2″ o.c.2x6 Hem-Fir · 24″ o.c.2x8 Hem-Fir · 12″ o.c.2x8 Hem-Fir · 16″ o.c.2x8 Hem-Fir · 19.2″ o.c.2x8 Hem-Fir · 24″ o.c.2x10 Hem-Fir · 12″ o.c.2x10 Hem-Fir · 16″ o.c.2x10 Hem-Fir · 19.2″ o.c.2x10 Hem-Fir · 24″ o.c.2x12 Hem-Fir · 12″ o.c.2x12 Hem-Fir · 16″ o.c.2x12 Hem-Fir · 19.2″ o.c.2x12 Hem-Fir · 24″ o.c.2x4 Spruce-Pine-Fir · 12″ o.c.2x4 Spruce-Pine-Fir · 16″ o.c.2x4 Spruce-Pine-Fir · 19.2″ o.c.2x4 Spruce-Pine-Fir · 24″ o.c.2x6 Spruce-Pine-Fir · 12″ o.c.2x6 Spruce-Pine-Fir · 16″ o.c.2x6 Spruce-Pine-Fir · 19.2″ o.c.2x6 Spruce-Pine-Fir · 24″ o.c.2x8 Spruce-Pine-Fir · 12″ o.c.2x8 Spruce-Pine-Fir · 16″ o.c.2x8 Spruce-Pine-Fir · 19.2″ o.c.2x8 Spruce-Pine-Fir · 24″ o.c.2x10 Spruce-Pine-Fir · 12″ o.c.2x10 Spruce-Pine-Fir · 16″ o.c.2x10 Spruce-Pine-Fir · 19.2″ o.c.2x10 Spruce-Pine-Fir · 24″ o.c.2x12 Spruce-Pine-Fir · 12″ o.c.2x12 Spruce-Pine-Fir · 16″ o.c.2x12 Spruce-Pine-Fir · 19.2″ o.c.2x12 Spruce-Pine-Fir · 24″ o.c.2x4 Southern Pine · 12″ o.c.2x4 Southern Pine · 16″ o.c.2x4 Southern Pine · 19.2″ o.c.2x4 Southern Pine · 24″ o.c.2x6 Southern Pine · 12″ o.c.2x6 Southern Pine · 16″ o.c.2x6 Southern Pine · 19.2″ o.c.2x6 Southern Pine · 24″ o.c.2x8 Southern Pine · 12″ o.c.2x8 Southern Pine · 16″ o.c.2x8 Southern Pine · 19.2″ o.c.2x8 Southern Pine · 24″ o.c.2x10 Southern Pine · 12″ o.c.2x10 Southern Pine · 16″ o.c.2x10 Southern Pine · 19.2″ o.c.2x10 Southern Pine · 24″ o.c.2x12 Southern Pine · 12″ o.c.2x12 Southern Pine · 16″ o.c.2x12 Southern Pine · 19.2″ o.c.2x12 Southern Pine · 24″ o.c.