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)
0.0180 1.04 33 0.0847 0.0884 0.0754 62.1 15.5 119 20.2
0.0180 1.04 50 0.0778 0.0822 0.0707 94.1 23.5 180 30.5
0.0240 1.36 33 0.128 0.130 0.114 116 29.1 222 37.7
0.0300 1.69 33 0.175 0.176 0.152 188 47.1 359 61.0
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)
0.0180 0.0180 0.0240 0.0300 0.0180 0.0180 0.0240 0.0300 0.0135 0.0180 0.0240 0.0300
Y.S.* (ksi) 33 50 33 33 33 50 33 33 33 50 33 33
4.0

4.0

 S 75 104 113 154 78 110 115 155 98 138 144 194
D 137 128 207 276 329 308 497 662 259 243 391 521
4.5

4.5

 S 59 82 89 122 62 87 91 123 77 109 114 153
D 96 90 145 194 231 217 349 465 182 171 275 366
5.0

5.0

 S 48 67 72 99 50 70 74 99 63 88 92 124
D 70 66 106 141 168 158 254 339 133 124 200 267
5.5

5.5

 S 40 55 60 82 41 58 61 82 52 73 76 103
D 53 49 80 106 126 119 191 255 100 93 151 200
6.0

6.0

 S 33 46 50 69 35 49 51 69 43 61 64 86
D 41 38 61 82 97 91 147 196 77 72 116 154
6.5

6.5

 S 28 39 43 58 30 42 44 59 37 52 55 74
D 32 30 48 64 77 72 116 154 60 57 91 121
7.0

7.0

 S 24 34 37 50 26 36 38 51 32 45 47 63
D 26 24 39 51 61 58 93 123 48 45 73 97
7.5

7.5

 S 21 30 32 44 22 31 33 44 28 39 41 55
D 21 19 31 42 50 47 75 100 39 37 59 79
8.0

8.0

 S 19 26 28 39 20 28 29 39 24 34 36 49
D 17 16 26 34 41 39 62 83 32 30 49 65
8.5

8.5

 S 17 23 25 34 17 24 26 34 22 30 32 43
D 14 13 22 29 34 32 52 69 27 25 41 54
9.0

9.0

 S 15 21 22 30 15 22 23 31 19 27 28 38
D 12 11 18 24 29 27 44 58 23 21 34 46
9.5

9.5

 S 13 18 20 27 14 20 20 28 17 24 26 34
D 10 10 15 21 25 23 37 49 19 18 29 39
10.0

10.0

 S 12 17 18 25 13 18 18 25 16 22 23 31
D 9 8 13 18 21 20 32 42 17 16 25 33

* Y.S. = Yield Strength