General – Presented in the load tables are maximum uniformly distributed specified loads.

Steel – Conforms to ASTM A653/A653M or A792/A792M. Grade 33/230; Yield stress 33 ksi/230 MPa and tensile stress 45 ksi/310 MPa. Grade 50 /345; Yield stress 50 ksi/345 MPa and tensile stress 65 ksi/450 MPa; Grade 80 /550; Yield stress 80 ksi/550 MPa and tensile stress 82 ksi/565 MPa.

Finishes – A25/ZF75, G90/Z275 or AZ50/AZM150. For heavier metallic coatings, refer to ASTM A653/A653M or A792/A792M.

Load Tables – The following information regarding the determination of the specified wind and snow loads is contained in the 2010 Edition of the National Building Code of Canada (NBCC).
Importance factors are applied to both strength (ULS) and serviceability/ deflection (SLS) limit state design considerations. A lower load factor for wind of 1.4, instead of 1.5 for live and snow loads, is now being used. This lower load factor for wind somewhat offsets the higher wind loads (1 in 50 year return) that are now listed in the NBCC by geographic location. The importance category of the end use of the building/structure must also be recognized, such as Normal or Low.

All of this will impact how the load tables are to be used. In an effort to help the design professional with the load tables, the information below was taken directly from Division B, Part 4 (Structural Design) of the NBCC.

Specified Wind Load

W = Iw qCeCgCp

Importance Category Importance Factor, Iw
ULS SLS
Low 0.8 0.75
Normal 1.0 0.75
High 1.15 0.75
Post-Disaster 1.25 0.75

Specified Snow Load

S = Is [Ss (Cb Cw Cs Ca) + Sr]

Importance Category Importance Factor, Iw
ULS SLS
Low 0.8 0.9
Normal 1.0 0.9
High 1.15 0.9
Post-Disaster 1.25 0.9

The importance factors, Iw and Is, have been incorporated in the load tables, as well as the importance category. The parameters in the boxed-in portion of Equations [1] and [2] must be determined by the design professional in accordance with the NBCC.

Strength – The maximum uniformly distributed specified load based on strength in the load table must be equal to or greater than the specified live load.

Serviceability (Deflection) – The maximum uniformly distributed specified load based on deflection in the load table must be equal to or greater than the specified live load. The effective
moment of inertia for deflection determination was calculated at an assumed specified live load stress of 0.6Fy.

EXAMPLE (Use of Load Table)

Ultra Span Wall (Normal Importance Category) 
Given: (Metric units)
(LLF = 1.4 and Iw = 0.75)
~ Deck thickness, t = 0.762 mm
~ Double span continuous, L = 2.6 m each span
~ Bearing length, N = 50 mm
~ L/240 deflection limit
~ Wind live load, LL = 1.5 kPa

The live load is the value of the boxed-in portion of the specified wind load expression [1].

Solution:
Strength “S”
1) Specified wind live load = 1.5 kPa
2) Maximum specified load (from Load Table)
Is 1.65 kPa

Since 1.65 > 1.5 … OK

3) Check web crippling (N = 50 mm)
a) End reaction = 0.375(1.5)2.6 = 1.46 kN/m (from section property table)
Pe = Pe1 + Pe2 [N/t]1/2 = 2.78 + 0.695[50/0.762]1/2 = 8.41 kN/m

Since 8.41 > 1.46 … OK

b) Interior reaction = 1.25(1.5)2.6 = 4.88 kN/m (from section property table)
Pi = Pi1 + Pi2 [N/t]1/2 = 5.29 + 0.900[50/0.762]1/2 = 12.6 kN/m

Since 12.6 > 4.88 … OK
Deflection “D”
From table L/180 = 3.26 kPa
For L/240, multiply 3.26 by 180/240 = 2.45 kPa
Since 2.45 > 1.5 … OK

  1. Based on ASTM A 653 structural steel.
  2. Values in row “S” are based on strength.
  3. Values in row “D” are based on deflection of 1/180th span.
  4. Web crippling not included in strength calculation. See example.
  5. Limit States Design principles were used in accordance with CSA Standard S136-12.

SECTION PROPERTIES | Per Foot of Width
Base Steel Thickness (inches) Weight [G90] (psf) Yield Stress (ksi) Section Modulus Deflection Moment of Inertia (in4) Specified Web Crippling Data
Midspan

(in3)

 Support

(in3)

 Pe1

End (lb)

 Pe2

End (lb)

 Pi1

Interior (lb)

 Pi1

Interior (lb)
0.0135 0.72 50 0.0268 0.0219 0.0309 20.7 5.17 40.2 6.84
0.0180 0.94 33 0.0406 0.0343 0.0435 25.9 6.47 50.2 8.53
0.0180 0.94 50 0.0385 0.0326 0.0430 39.2 9.80 76.0 12.9
0.0180 0.94 80 0.0376 0.0315 0.0426 46.6 11.7 90.4 15.4
0.0240 1.23 33 0.0571 0.0476 0.0579 48.6 12.2 93.8 16.0
0.0300 1.53 33 0.0710 0.0613 0.0722 78.7 19.7 152 25.8
LLF = 1.40; IMPF = 0.75; NORMAL OCCUPANCY = 1.0
LOAD TABLE | Maximum Uniformly Distributed Specified Loads (psf).
Span Length (ft) 1-Span

Base Steel Thickness (inches)

 2-Span

Base Steel Thickness (inches)

 3-Span

Base Steel Thickness (inches)
0.0135 0.0180 0.0180 0.0180 0.0240 0.0300 0.0135 0.0180 0.0180 0.0180 0.0240 0.0300 0.0135 0.0180 0.0180 0.0180 0.0240 0.0300
Y.S.* (ksi) 50 33 50 80 33 33 50 33 50 80 33 33 50 33 50 80 33 33
2.0

2.0

 S 144 144 206 239 202 251 117 121 175 201 168 217 147 152 219 251 210 271
D 450 632 626 620 842 1050 1080 1517 1502 1487 2020 2521 850 1195 1183 1171 1591 1985
2.5

2.5

 S 92 92 132 153 129 161 75 78 112 128 108 139 94 97 140 161 135 173
D 230 324 320 317 431 538 553 777 769 761 1034 1291 435 612 606 600 814 1017
3.0

3.0

 S 64 64 92 106 90 112 52 54 78 89 75 96 65 67 97 111 93 120
D 133 187 185 184 249 311 320 449 445 441 598 747 252 354 351 347 471 588
3.5

3.5

 S 47 47 67 78 66 82 38 40 57 66 55 71 48 50 71 82 69 88
D 84 118 117 116 157 196 201 283 280 277 377 470 159 223 221 218 297 370
4.0

4.0

 S 36 36 51 60 50 63 29 30 44 50 42 54 37 38 55 63 53 68
D 56 79 78 77 105 131 135 190 188 186 252 315 106 149 148 146 199 248
4.5

4.5

 S 28 28 41 47 40 50 23 24 35 40 33 43 29 30 43 50 42 53
D 39 55 55 54 74 92 95 133 132 131 177 221 75 105 104 103 140 174
5.0

5.0

 S 23 23 33 38 32 40 19 19 28 32 27 35 23 24 35 40 34 43
D 29 40 40 40 54 67 69 97 96 95 129 161 54 76 76 75 102 127
5.5

5.5

 S 19 19 27 32 27 33 16 16 23 27 22 29 19 20 29 33 28 36
D 22 30 30 30 40 51 52 73 72 71 97 121 41 57 57 56 76 95
6.0

6.0

 S 16 16 23 27 22 28 13 13 19 22 19 24 16 17 24 28 23 30
D 17 23 23 23 31 39 40 56 56 55 75 93 31 44 44 43 59 74
6.5

6.5

 S 14 14 20 23 19 24 11 11 17 19 16 21 14 14 21 24 20 26
D 13 18 18 18 25 31 31 44 44 43 59 73 25 35 34 34 46 58
7.0

7.0

 S 12 12 17 20 16 20 10 10 14 16 14 18 12 12 18 20 17 22
D 10 15 15 14 20 25 25 35 35 35 47 59 20 28 28 27 37 46
7.5

7.5

 S 10 10 15 17 14 18 8 9 12 14 12 15 10 11 16 18 15 19
D 9 12 12 12 16 20 20 29 28 28 38 48 16 23 22 22 30 38
8.0

8.0

 S 9 9 13 15 13 16 7 8 11 13 11 14 9 9 14 16 13 17
D 7 10 10 10 13 16 17 24 23 23 32 39 13 19 18 18 25 31

* Y.S. = Yield Strength