Page 281 - 2018_IRC

WALL CONSTRUCTION

TABLE R603.7(1)
TOTAL NUMBER OF JACK AND KING STUDS REQUIRED AT EACH END OF AN OPENING
SIZE OF OPENING 24-INCH O.C. STUD SPACING 16-INCH O.C. STUD SPACING
(feet-inches) No. of jack studs No. of king studs No. of jack studs No. of king studs
Up to 3′-6″ 1 1 1 1
> 3′-6″ to 5′-0″ 1 2 1 2
> 5′-0″ to 5′-6″ 1 2 2 2
> 5′-6″ to 8′-0″ 1 2 2 2
> 8′-0″ to 10′-6″ 2 2 2 3
> 10′-6″ to 12′-0″ 2 2 3 3
> 12′-0″ to 13′-0″ 2 3 3 3
> 13′-0″ to 14′-0″ 2 3 3 4
> 14′-0″ to 16′-0″ 2 3 3 4
> 16′-0″ to 18′-0″ 3 3 4 4
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

TABLE R603.7(2)
HEADER TO KING STUD CONNECTION REQUIREMENTS a, b, c, d
ULTIMATE WIND SPEED (mph), EXPOSURE CATEGORY
HEADER SPAN 130 B <140 B
(feet) 115 B 120 B 130 C <140 C
115 C 120 C
≤ 4 4-No. 8 screws 4-No. 8 screws 4-No. 8 screws 4-No. 8 screws 6-No. 8 screws 6-No. 8 screws
> 4 to 8 4-No. 8 screws 4-No. 8 screws 4-No. 8 screws 6-No. 8 screws 8-No. 8 screws 8-No. 8 screws
> 8 to 12 4-No. 8 screws 6-No. 8 screws 6-No. 8 screws 8-No. 8 screws 10-No. 8 screws 12-No. 8 screws
> 12 to 16 4-No. 8 screws 6-No. 8 screws 8-No. 8 screws 10-No. 8 screws 12-No. 8 screws 14-No. 8 screws

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound = 4.448 N.
a. All screw sizes shown are minimum.
b. For headers located on the first floor of a two-story building or the first or second floor of a three-story building, the total number of screws is permitted to be
reduced by 2 screws, but the total number of screws shall be not less than four.
c. For roof slopes of 6:12 or greater, the required number of screws shall be permitted to be reduced by half, but the total number of screws shall be not less than
four.
d. Screws can be replaced by an uplift connector that has a capacity of the number of screws multiplied by 164 pounds.

TABLE R603.8
HEAD AND SILL TRACK SPAN
ULTIMATE WIND ALLOWABLE HEAD AND SILL TRACK SPAN a, b, c
SPEED AND (feet-inches)
EXPOSURE CATEGORY
(mph) TRACK DESIGNATION d
B C 350T125-33 350T125-43 350T125-54 550T125-33 550T125-43 550T125-54
115 — 5′-9″ 6′-9″ 9′-3″ 7′-3″ 9′-1″ 12′-5″
120 — 5′-6″ 6′-6″ 8′-11″ 7′-0″ 8′-9″ 11′-11″
130 115 4′-10″ 5′-9″ 7′-10″ 6′-2″ 7′-8″ 10′-6″
< 140 120 4′-8″ 5′-6″ 7′-6″ 5′-11″ 7′-4″ 10′-1″
— 1 3 0 4 ′-3″ 5′-1″ 6′-11″ 5′-6″ 6′-9″ 9′-4″
— < 1 4 0 4 ′-0″ 4′-9″ 6′-5″ 5′-1″ 6′-4″ 8′-8″

For SI: 1 mil = 0.0254 mm, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 ksi = 1,000 psi = 6.895 MPa.
a. Deflection limit: L/240.
b. Head and sill track spans are based on components and cladding wind pressures and 48-inch tributary span.
c. For openings less than 4 feet in height that have both a head track and sill track, the spans are permitted to be multiplied by 1.75. For openings less than or
equal to 6 feet in height that have both a head track and a sill track, the spans are permitted to be multiplied by a factor of 1.5.
d. Minimum Grade 33 ksi steel shall be used for 33 mil and 43 mil thicknesses. Minimum Grade 50 ksi steel shall be used for 54 and 68 mil thicknesses.

256 2018 INTERNATIONAL RESIDENTIAL CODE ®
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