The Ontario Building Code | Loads and Effects
4.1.2.1. Loads and Effects
(1) Except as provided in Article 4.1.2.2., the categories of loads, specified loads and effects set out in Table 4.1.2.1.A. shall be taken into consideration in the design of a building and its structural members and connections.
Table 4.1.2.1.A.
Categories of Loads, Specified Loads and Effects
Forming Part of Sentence 4.1.2.1.(1)
| Item | Column 1 Symbol | Column 2 Loads, Specified Loads and Effects (1) |
| 1. | D | dead load – a permanent load (2) due to the weight of building components as specified in Subsection 4.1.4. |
| 2. | E | earthquake load and effects – a rare load (4) due to an earthquake, as specified in Subsection 4.1.8. |
| 3. | H | a permanent load (2) due to lateral earth pressure, including groundwater |
| 4. | L | live load – a variable load (3) due to intended use and occupancy (including loads due to cranes and the pressure of liquids in containers), as specified in Subsection 4.1.5. |
| 5. | LXC | live load exclusive of crane loads |
| 6. | C | live load due to cranes including self weight |
| 7. | Cd | self weight of all cranes positioned for maximum effects |
| 8. | C7 | crane bumper impact load |
| 9. | P | permanent effects caused by prestress |
| 10. | S | variable load (3) due to snow including ice and associated rain, as specified in Article 4.1.6.2., or due to rain, as specified in Article 4.1.6.4. |
| 11. | T | effects due to contraction, expansion, or deflection caused by temperature changes, shrinkage, moisture changes, creep, ground settlement, or a combination of them |
| 12. | W | wind load – a variable load (3) due to wind, as specified in Subsection 4.1.7. |
Notes to Table 4.1.2.1.A.:
(1) Load means the imposed deformations (i.e., deflections, displacements or motions that induce deformations and forces in the structure), forces and pressures applied to the buildingstructure.
(2) Permanent load is a load that changes very little once it has been applied to the structure, except during repair.
(3) Variable load is a load that frequently changes in magnitude, direction or location.
(4) Rare load is a load that occurs infrequently and for a short time only.
(2) Minimum specified values of the loads described in Sentence (1), as set forth in Subsections 4.1.4. to 4.1.8., shall be increased to account for dynamic effects where applicable.
(3) For the purpose of determining specified loads S, W or E in Subsections 4.1.6. to 4.1.8., buildings shall be assigned an Importance Category based on intended use and occupancy, in accordance with Table 4.1.2.1.B.
Table 4.1.2.1.B.
Importance Categories for Buildings
Forming Part of Sentence 4.1.2.1.(3)
| Item | Column 1 Use and Occupancy | Column 2 Importance Category |
| 1. | Buildings that represent a low direct or indirect hazard to human life in the event of failure, including: |
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| • low human-occupancy buildings, where it can be shown that collapse is not likely to cause injury or other serious consequences | Low |
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| • minor storage buildings |
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| 2. | All buildings except those listed in Importance Categories Low, High and Post-disaster | Normal |
| 3. | Buildings that are likely to be used as post-disaster shelters, including buildings whose primary use is: |
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| • as an elementary, middle or secondary school | High |
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| • as a community centre |
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| Manufacturing and storage facilities containing toxic, explosive or other hazardous substances in sufficient quantities to be dangerous to the public if released |
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| 4. | Post-disaster buildings | Post-disaster |