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 CategoryImportance Factor, Iw
ULSSLS
Low0.80.75
Normal1.00.75
High1.150.75
Post-Disaster1.250.75

Specified Snow Load

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

Importance CategoryImportance Factor, Iw
ULSSLS
Low0.80.9
Normal1.00.9
High1.150.9
Post-Disaster1.250.9

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 ModulusDeflection Moment of Inertia (in4)Specified Web Crippling Data
Midspan

(in3)

Support

(in3)

Pe1

End (lb)

Pe2

End (lb)

Pi1

Interior (lb)

Pi1

Interior (lb)

0.01350.74800.04040.04040.0177
0.01800.97330.05310.05310.0232
0.01800.97500.05310.05310.0232
0.02401.27330.06970.06970.0305
0.03001.58330.08560.08560.0375
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)

0.01350.01800.01800.02400.03000.01350.01800.01800.02400.03000.01350.01800.01800.02400.0300
Y.S.* (ksi)803350333380335033338033503333
2.0

2.0

S259188285246303259188285246303324235356308378
D257338338443545616811811106413074856396398381029
2.5

2.5

S166120182158194166120182158194208150228197242
D131173173227279315415415545669248327327429527
3.0

3.0

S1158412710913511584127109135144104158137168
D76100100131161183240240315387144189189248305
3.5

3.5

S8561938099856193809910677116101124
D4863638310211515115119824491119119156192
4.0

4.0

S654771627665477162768159897795
D324242556877101101133163618080105129
4.5

4.5

S513756496051375649606446706175
D2330303948547171931154356567490
5.0

5.0

S423046394842304639485238574961
D162222283539525268843141415466
5.5

5.5

S342538334034253833404331474150
D121616212630393951632331314049
6.0

6.0

S2132273429213227343626403442
D1313162023303039481824243138
6.5

6.5

S232925182723293122342936
D131618242431381419192430
7.0

7.0

S202521152320252619292531
D101314191925301115152024
7.5

7.5

S22181320182217252227
D10121515202512121620
8.0

8.0

S121815191924
D131317201316

* Y.S. = Yield Strength