Series¹

Depth
(in)

Weight
(plf)

Allowable
Moment²
@ 100%
(ft - lb)

Allowable
Shear^2,3
@ 100%
(lb)

Maximum
End
Reaction³

EI x 10⁶
(in² - lb)

GA x 10⁵
(lb)

SWI-24

9-1/2"

1.9

2105

900

900

133

4.9

SWI-24

11-1/4"

2.1

2725

1000

1000

211

6.4

SWI-24

11-7/8"

2.2

2920

1000

1000

238

6.9

SWI-24

14"

2.3

3590

1000

1000

344

8.6

SWI-24S

14"

2.3

3590

1300

1300

344

8.6

-

-

-

-

-

-

-

-

SWI-34

9-1/2"

2.6

3405

1000

1000

216

4.9

SWI-34

11-1/4"

2.8

4400

1200

1200

340

6.4

SWI-34

11-7/8"

2.9

4725

1200

1200

385

6.9

SWI-34

14"

3.0

5795

1200

1200

556

8.6

SWI-34

16"

3.2

6815

1100

1100

747

10.1

SWI-34S

14"

3.0

5795

1500

1500

556

8.6

SWI-34S

16"

3.2

6815

1700

1700

747

10.1

-

-

-

-

-

-

-

-

SWI-44S

18"

4.1

10450

1900

1900

1291

11.7

SWI-44S

20"

4.3

11815

2100

2100

1620

13.3

NOTES:

1. Series SWI-24 flanges are 2 x 2 inches (51 mm x 51 mm), Series SWI-34 flanges are 2 x 3 inches (51 mm x 76 mm) and Series SWI-44 flanges are 2x4 inches (51 mm x 102 mm).
2. Moment and shear values and end reactions are for normal duration of load and are permitted to be increased in accordance with Chapter 16 of the 1994 Uniform Building Code (UBC).
3. Allowable shear and end reactions are shown without web stiffeners. The Suffix "S" indicates a web stiffener is required.
4. Maximum end reaction is based on 2 inch (51 mm) bearing length for 24 Series Joists and 2-1/2" (64 mm) bearing length for 34 and 44 Series Joists.

5.      Deflection calculations must include both bending and shear deformation. The formulas above shall be used to determine total deflection.

Deflection due to Uniform Loads:
Defl. = (22.5WL⁴/EI) + (1.5PL/GA)

Deflection due to Concentrated Load at Joist Center Span:
Defl. = (36PL³/EI) + (3PL/GA)

W = The uniform load in pounds per lineal foot.
L = The effective length (span of joist) in feet.
EI = The product of the moment of inertia and modulus of elasticity as given in SWI-Joist design properties.
P = The concentrated load in pounds.
GA = Product of the shear modulus of the web material and the web area between the joist flanges as given in SWI-Joist design properties.
Defl. = Deflection in inches, resulting from the application of the above formulas.

Series

Depth
(in)

Weight
(plf)

Allowable
Moment
@ 100%
(ft - lb)

Allowable
Shear
@ 100%
(lb)

EI x 10⁶
(in² - lb)

GA x 10⁵
(lb)

SWII-42

7-1/4"

3.7

2081

1170

134

7.1

SWII-42

9-1/4"

4.3

2934

1610

240

10.5

SWII-42

11-1/4"

4.6

3801

2050

378

13.9

-

-

-

-

-

-

-

SWII-62

7-1/4"

4.8

3270

1170

209

7.1

SWII-62

9-1/4"

5.4

4610

1610

377

10.5

SWII-62

11-1/4"

6.0

5972

2050

378593

13.9

NOTES:

1. Deflection of uniformly loaded, simple span SWII-Headers may be calculated as:

Defl. = (22.5WL⁴/EI) + (1.5WL²/GA)

Where:

W = Uniform Load (plf).
L = Clear Span (ft).
EI = The product of Modulus of Elasticity and Moment of Inertia.
GA = The product of Shear Modulus of the web material and the web area between the joist flanges.
Defl. = Deflection in inches.