Span charts and 2012 IRC building codes for girders and headers. Includes span tables for all load bearing locations and the number of jack studs. These charts are for 30 pound per square foot snow load on the roof. All other data is available on page 121 of the 2012 International Residential Code.
Girders are found in floor systems spanning across piers and support the weight of floor joists. They are often positioned beneath load bearing walls. Headers are found in walls. Although single plies are permitted they are not recommended. Both headers and girders are beams that are oriented horizontally and transfer load down to walls, piers, or posts.
Their is no notching permitted in the center third of any beam. Notches on the outer thirds must not exceed 1/6 of the width of the board. The bottom of any beam may be notched only on its end. The notch can not exceed 25% of the width of the board.
Nail each ply of a beam with a minimum of 10d nails. Use two nails on each end and at splices. Stagger the rest of the nails 32″ o.c.
Header Spans for Exterior Walls on Buildings 20′ Wide
| Number of plies and jacks in ( ) | (2)2 x 8 | (2)2 x 10 | (2)2 x 12 | (3)2 x 10 | (3)2 x 12 | (4)2 x 12 |
| Roof, ceiling | 6′ 10″(1) | 8′ 5″(2) | 9′ 9″(2) | 10’6″(1) | 12′ 2″(2) | 14′ 1″(1) |
| Roof, ceiling, center bearing floor | 5′ 9″(2) | 7′ 0″(2) | 8′ 1″(2) | 8′ 9″(2) | 10′ 2″(2) | 11′ 9″(2) |
| Roof, ceiling, clear span floor | 5′ 0″(2) | 6′ 1″(2) | 7′ 1″(2) | 7′ 7″(2) | 8′ 10″(2) | 10′ 2″(2) |
| Roof, ceiling, 2 center bearing floors | 4′ 9″(2) | 5′ 9″(2) | 6′ 8″(2) | 7′ 3″(2) | 8′ 5″(2) | 9′ 8″(2) |
| Roof, ceiling, 2 clear span floors | 3′ 10″(2) | 4′ 9 (2)* | 5′ 6″ (3)* | 5′ 11″(2) | 6′ 10″(2) | 7′ 11″(2) |
Header Spans for Exterior Walls on Buildings 28′ Wide
| Number of plies and jacks in ( ) | (2)2 x 8 | (2)2 x 10 | (2)2 x 12 | (3)2 x 10 | (3)2 x 12 | (4)2 x 12 |
| Roof, ceiling | 5′ 11″(2) | 7′ 3″(2) | 8′ 5″(2) | 9′ 1″(2) | 10′ 7″(2) | 12′ 2″(2) |
| Roof, ceiling, center bearing floor | 5′ 0″(2) | 6′ 2″(2) | 7′ 1″(2) | 7′ 8″(2) | 8′ 11″(2) | 10′ 3″(2) |
| Roof, ceiling, clear span floor | 4′ 4″(2) | 5′ 3″(2) | 6′ 1″(3) | 6′ 7″(2) | 7′ 8″(2) | 8′ 10″(2) |
| Roof, ceiling, 2 center bearing floors | 4′ 2″(2) | 5′ 1″(2) | 5′ 10″(3) | 6′ 4″(2) | 7′ 4″(2) | 8′ 6″(2) |
| Roof, ceiling, 2 clear span floors | 3′ 4″(2) | 4′ 1″(3) | 4′ 9″ (3) | 5′ 1″(2) | 5′ 11″ (3) | 6′ 10″(2) |
Header Spans for Exterior Walls on Buildings 36′ Wide
| Number of plies and jacks in ( ) | (2)2 x 8 | (2)2 x 10 | (2)2 x 12 | (3)2 x 10 | (3)2 x 12 | (4)2 x 12 |
| Roof, ceiling | 5′ 4″(2) | 6′ 6″(2) | 7′ 6″(2) | 8′ 2″(2) | 9′ 5″(2) | 10′ 11″(2) |
| Roof, ceiling, center bearing floor | 4′ 6″(2) | 5′ 6″(2) | 6′ 5″(2) | 6′ 11″(2) | 8′ 0″(2) | 9′ 3″(2) |
| Roof, ceiling, clear span floor | 3′ 10″(2) | 4′ 8″(2) | 5′ 5″(3) | 5′ 11″(2) | 6′ 10″(2) | 7′ 11″(2) |
| Roof, ceiling, 2 center bearing floors | 3′ 9″(2) | 4′ 7″(3) | 5′ 3″(3) | 5′ 8″(2) | 6′ 7″(2) | 7′ 8″(2) |
| Roof, ceiling, 2 clear span floors | 3′ 0″(3) | 3′ 8″(3) | 4′ 3″(3) | 4′ 7″(3) | 5′ 4″ (3) | 6′ 2″(3) |
Header Spans for Interior Walls
| Number of plies and jacks in ( ) | (2)2 x 8 | (2)2 x 10 | (2)2 x 12 | (3)2 x 10 | (3)2 x 12 | (4)2 x 12 |
| One floor only (20′ wide) | 5′ 9″(1) | 7′ 0″(2) | 8′ 1″(2) | 8′ 9″(1) | 10′ 2″(2) | 11′ 9″(1) |
| Two floors (20′ wide) | 4′ 1″(2) | 4′ 11″(2) | 5′ 9″(2) | 6′ 2″(2) | 7′ 2″(2) | 8′ 4″(2) |
| One floor only (28′ wide) | 5′ 0″(2) | 6′ 1″(2) | 7′ 0″(2) | 7′ 7″(2) | 8′ 10″(2) | 10′ 2″(2) |
| Two floors (28′ wide) | 3′ 6″(2) | 4′ 3″(2) | 5′ 0″(3) | 5′ 4″(2) | 6′ 3″(2) | 7′ 2″(2) |
| One floor only (36′ wide) | 4′ 5″(2) | 5′ 5″(2) | 6′ 3″(2) | 6′ 9″(2) | 7′ 10″ (2) | 9′ 1″(2) |
| Two floors (36′ wide) | 3′ 2″(2) | 3′ 10″(3) | 4′ 5″(3) | 4′ 10″(2) | 5′ 7″(3) | 6′ 5″(2) |
