Structural I

The term ‘Structural I’ appearing on an APA trademark indicates that the OSB structural-panel meets the requirements of a Performance Rated panel.  This delivers superior design capacity for these panels over OSB Rated Sheathing and Sturd-I-Floor.

Comparison of Superior Design Capacities for OSB Structural I Sheathing with OSB Rated Sheathing.

In addition, Structural I panels meet the further requirements under Performance Standard US PS 2 for cross-panel strength and stiffness in bending and for racking load performance. These four tables compare the bending stiffness and strength for:

  • Structural 1 with OSB Rated Sheathing and
  • OSB Structural I Sturd-I-Floor with OSB Rated Sturd-I-Floor

OSB Structural 1 and OSB Rated Sheathing: Bending Stiffness EI (lb-in2/ft of panel width)

Span

Rating

Performance Category

Predominant

Thickness Label

Stress applied

parallel to strength

axis1

Stress applied perpendicular to strength

axis1

Rated

Sheathing

Structural I

Sheathing

Rated

Sheathing

Structural I

Sheathing

Roof-24

3/8

0.354 IN

60,000

60,000

11,000

17,600

Roof-24 Subfloor-16

7/16

0.418 IN

78,000

78,000

16,000

25,600

Roof-32 Subfloor-16

15/32

0.451 IN

115,000

115,000

25,000

40,000

Roof-40 Subfloor-20

19/32

0.578 IN

225,000

225,000

56,000

89,600

Roof-48 Subfloor-24

23/32

0.704 IN

400,000

400,000

91,500

146,600

Note:1  The strength axis is parallel to the face and back orientation of the strands unless   otherwise indicated.

OSB Bending Strength FbS (lb-in2/ft of panel width)

Span

Rating

Performance Category

Predominant

Thickness Label

Stress applied

parallel to strength

axis1

Stress applied perpendicular to strength

axis1

Rated

Sheathing

Structural I

Sheathing

Rated

Sheathing

Structural I

Sheathing

Roof-24

3/8

0.354 IN

300

300

97

145.5

Roof-24 Subfloor-16

7/16

0.418 IN

385

385

115

172.5

Roof-32 Subfloor-16

15/32

0.451 IN

445

445

165

247.5

Roof-40 Subfloor-20

19/32

0.578 IN

750

750

270

405

Roof-48 Subfloor-24

23/32

0.704 IN

1,000

1,000

405

607.5

Note:1   The strength axis is parallel to the face and back orientation of the strands unless otherwise indicated.

OSB Structural I Sturd-I-Floor with OSB Rated Sturd-I-Floor

OSB Bending Stiffness EI (lb-in2/ft of panel width)

Span

Rating

Performance Category

Predominant

Thickness Label

Stress applied

parallel to strength

axis1

Stress applied perpendicular to strength

axis1

Rated

Sheathing

Structural I

Sheathing

Rated

Sheathing

Structural I

Sheathing

16 oc

19/32

0.578

150,000

150,000

34,000

54,400

20 oc

19/32

0.578

210,000

210,000

40,500

64,800

24 oc

23/32

0.704

300,000

300,000

80,500

128,800

32 oc

7/8

0.849

650,000

650,000

235,000

376,000

48 oc

1-1/8

1.091

1,150,000

1,150,000

495,000

792,000

Note:1 The strength axis is parallel to the face and back orientation of the strands unless otherwise indicated.

                                                                                                                     

OSB Bending Strength FbS (lb-in2/ft of panel width)

Span

Rating

Performance Category

Predominant

Thickness Label

Stress applied

parallel to strength

axis1

Stress applied perpendicular to strength

axis1

Rated

Sheathing

Structural I

Sheathing

Rated

Sheathing

Structural I

Sheathing

16 oc

19/32

0.578

500

500

180

270

20 oc

19/32

0.578

575

575

250

375

24 oc

23/32

0.704

770

770

385

577.5

32 oc

7/8

0.849

1,050

1,050

685

1,027.5

48 oc

1-1/8

1.091

1,900

1,900

1,200

1,800

Note:1  The strength axis is parallel to the face and back orientation of the strands unless otherwise indicated.