UpCodes logo
// CODE SNIPPET

2308.7.12 Roof Planking

Building Code 2021 of Illinois > 23 Wood > 2308 Conventional Light-Frame Construction > 2308.7 Roof and Ceiling Framing > 2308.7.12 Roof Planking
Go To Full Code Chapter
Planking shall be designed in accordance with the general provisions of this code.
In lieu of such design, 2-inch (51 mm) tongue-and groove planking is permitted in accordance with Table 2308.7.12. Joints in such planking are permitted to be randomly spaced, provided that the system is applied to not less than three continuous spans, planks are center matched and end matched or splined, each plank bears on one support or more, and joints are separated by not less than 24 inches (610 mm) in adjacent pieces.
TABLE 2308.7.12
ALLOWABLE SPANS FOR 2-INCH TONGUE-AND-GROOVE DECKING
SPANa (feet) LIVE LOAD (pounds per square foot) DEFLECTION LIMIT BENDING STRESS (f) (pounds per square inch) MODULUS OF ELASTICITY (E) (pounds per square inch)
Roofs
4
20
1/240
160
170,000
1/360
256,000
30
1/240
210
256,000
1/360
384,000
40
1/240
270
340,000
1/360
512,000
4.5
20
1/240
200
242,000
1/360
305,000
30
1/240
270
363,000
1/360
405,000
40
1/240
350
484,000
1/360
725,000
5.0
20
1/240
250
332,000
1/360
500,000
30
1/240
330
495,000
1/360
742,000
40
1/240
420
660,000
1/360
1,000,000
5.5
20
1/240
300
442,000
1/360
660,000
30
1/240
400
662,000
1/360
998,000
40
1/240
500
884,000
1/360
1,330,000
6.0
20
1/240
360
575,000
1/360
862,000
30
1/240
480
862,000
1/360
1,295,000
40
1/240
600
1,150,000
1/360
1,730,000
6.5
20
1/240
420
595,000
1/360
892,000
30
1/240
560
892,000
1/360
1,340,000
40
1/240
700
1,190,000
1/360
1,730,000
7.0
20
1/240
490
910,000
1/360
1,360,000
30
1/240
650
1,370,000
1/360
2,000,000
40
1/240
810
1,820,000
1/360
2,725,000
7.5
20
1/240
560
1,125,000
1/360
1,685,000
30
1/240
750
1,685,000
1/360
2,530,000
40
1/240
930
2,250,000
1/360
3,380,000
8.0
20
1/240
640
1,360,000
1/360
2,040,000
30
1/240
850
2,040,000
1/360
3,060,000
Floors
4
40
1/360
840
1,000,000
4.5
950
1,300,000
5.0
1,060
1,600,000
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kN/m2, 1 pound per square inch = 0.00689 N/mm2.
  1. Spans are based on simple beam action with 10 pounds per square foot dead load and provisions for a 300-pound concentrated load on a 12-inch width of decking. Random layup is permitted in accordance with the provisions of Section 2308.7.12. Lumber thickness is 11/2 inches nominal.
Upcodes Diagrams

Related Code Sections

2308.7.12 Wood, Roof Planking
Planking shall be designed in accordance with the general provisions of this code. In lieu of such design, 2-inch (51 mm) tongue-and groove ...
Building Code 2021 of Illinois > 23 Wood > 2308 Conventional Light-Frame Construction > 2308.7 Roof and Ceiling Framing > 2308.7.12 Roof Planking
2308.7.12 Wood, Roof Planking
Planking shall be designed in accordance with the general provisions of this code. In lieu of such design, 2-inch (51 mm) tongue-and groove ...
Building Code 2018 of Illinois > 23 Wood > 2308 Conventional Light-Frame Construction > 2308.7 Roof and Ceiling Framing > 2308.7.12 Roof Planking
2304.11.4.2 Wood, Sawn, Wood Structural Panel, or Glued-Laminated Plank Roofs
Sawn, wood structural panel, or glued-laminated plank roofs shall be one of the following: Sawn or glued laminated, splined or tongue-and-groove ...
Building Code 2018 of Illinois > 23 Wood > 2304 General Construction Requirements > 2304.11 Heavy Timber Construction > 2304.11.4 Roof Decks > 2304.11.4.2 Sawn, Wood Structural Panel, or Glued-Laminated Plank Roofs
2304.11.4.2 Wood, Sawn, Wood Structural Panel, or Glued-Laminated Plank Roofs
Sawn, wood structural panel, or glued-laminated plank roofs shall be one of the following: Sawn or glued laminated, splined or tongue-and-groove ...
Building Code 2021 of Illinois > 23 Wood > 2304 General Construction Requirements > 2304.11 Heavy Timber Construction > 2304.11.4 Roof Decks > 2304.11.4.2 Sawn, Wood Structural Panel, or Glued-Laminated Plank Roofs