1. Except as provided in Sentence (2), the specified live load on an area of floor or roof depends on the intended use and occupancy, and shall not be less than either the uniformly distributed load patterns listed in Article 4.1.5.3., the loads due to the intended use and occupancy, or the concentrated loads listed in Article 4.1.5.9., whichever produces the most critical effect. (See Note A-4.1.5.1.(1).)
2. For buildings in the Low Importance Category as described in Table 4.1.2.1., a factor of 0.8 may be applied to the live load.

1. Except as provided in Sentence (2), where the use of an area of floor or roof is not provided for in Article 4.1.5.3., the specified live loads due to the use and occupancy of the area shall be determined from an analysis of the loads resulting from the weight of
   1. the probable assembly of persons,
   2. the probable accumulation of equipment and furnishings, and
   3. the probable storage of materials.
2. For buildings in the Low Importance Category as described in Table 4.1.2.1., a factor of 0.8 may be applied to the live load.

1. The uniformly distributed live load shall be not less than the value listed in Table 4.1.5.3., which may be reduced as provided in Article 4.1.5.8., applied uniformly over the entire area or on any portions of the area, whichever produces the most critical effects in the members concerned.

   
   Table 4.1.5.3.
   Specified Uniformly Distributed Live Loads on an Area of Floor or Roof
   Forming Part of Sentence 4.1.5.3.(1)

   

   Notes to Table 4.1.5.3.:
   (1) See Note A-Table 4.1.5.3.
   (2) See Article 4.1.5.6.
   (3) See Article 4.1.5.4.
   (4) See Sentence 4.1.5.1.(1).
   (5) See Article 4.1.5.5.

1. The following shall be designed to carry not less than the specified load required for the occupancy they serve, provided they cannot be used by an assembly of people as a viewing area:
   1. corridors, lobbies and aisles not more than 1 200 mm wide,
   2. all corridors above the first storey of residential areas of apartments, hotels and motels, and
   3. interior balconies and mezzanines.

1. Exterior areas accessible to vehicular traffic shall be designed for their intended use, including the weight of firefighting equipment, but not for less than the snow and rain loads prescribed in Subsection 4.1.6.
2. Except as provided in Sentences (3) and (4), roofs shall be designed for either the uniform live loads specified in Table 4.1.5.3., the concentrated live loads listed in Table 4.1.5.9., or the snow and rain loads prescribed in Subsection 4.1.6., whichever produces the most critical effects in the members concerned.
3. Exterior areas accessible to pedestrian traffic, but not vehicular traffic, shall be designed for their intended use, but not for less than the greater of
   1. the live load prescribed for assembly areas in Table 4.1.5.3., or
   2. the snow and rain loads prescribed in Subsection 4.1.6.
4. Roof parking decks shall be designed for either the uniformly distributed live loads specified in Table 4.1.5.3., the concentrated live loads listed in Table 4.1.5.9., or the roof snow load, whichever produces the most critical effect in the members concerned.

1. The minimum specified live load listed in Table 4.1.5.3. for dining areas may be reduced to 2.4 kPa for areas in buildings that are being converted to dining areas, provided that the floor area does not exceed 100 m2 and the dining area will not be used for other assembly purposes, including dancing.

1. Where an area of floor or roof is intended for 2 or more occupancies at different times, the value to be used from Table 4.1.5.3. shall be the greatest value for any of the occupancies concerned.

1. An area used for assembly occupancies designed for a live load of less than 4.8 kPa and roofs designed for the minimum loading specified in Table 4.1.5.3. shall have no reduction for tributary area.
2. Where a structural member supports a tributary area of a floor or a roof, or a combination thereof, that is greater than 80 m2 and either used for assembly occupancies designed for a live load of 4.8 kPa or more, or used for storage, manufacturing, retail stores, garages or as a footbridge, the specified live load due to use and occupancy is the load specified in Article 4.1.5.3. multiplied by
   
   where A is the tributary area in square metres for this type of use and occupancy.
3. Where a structural member supports a tributary area of a floor or a roof, or a combination thereof, that is greater than 20 m2 and used for any use or occupancy other than those indicated in Sentences (1) and (2), the specified live load due to use and occupancy is the load specified in Article 4.1.5.3. multiplied by
   where B is the tributary area in square metres for this type of use and occupancy.
4. Where the specified live load for a floor is reduced in accordance with Sentence (2) or (3), the structural drawings shall indicate that a live load reduction factor for tributary area has been applied.

1. The specified live load due to possible concentrations of load resulting from the use of an area of floor or roof shall not be less than that listed in Table 4.1.5.9. applied over the loaded area noted and located so as to cause maximum effects, except that for occupancies not listed in Table 4.1.5.9., the concentrations of load shall be determined in accordance with Article 4.1.5.2.

Table 4.1.5.9.
Specified Concentrated Live Loads on an Area of Floor or Roof
Forming Part of Sentence 4.1.5.9.(1)

Notes to Table 4.1.5.9.:
(1) See Note A-Table 4.1.5.9.

1. The floor assembly and other structural elements that support fixed seats in any building used for assembly occupancies accommodating large numbers of people at one time, such as grandstands, stadia and theatre balconies, shall be designed to resist a horizontal force equal to not less than 0.3 kN for each metre length of seats acting parallel to each row of seats, and not less than 0.15 kN for each metre length of seats acting at right angles to each row of seats, based on the assumption that these forces are acting independently of each other.

1. The minimum specified load due to equipment, machinery or other objects that may produce impact shall be the sum of the weight of the equipment or machinery and its maximum lifting capacity, multiplied by an appropriate factor listed in Table 4.1.5.11.
2. Crane-supporting structures shall be designed for the appropriate load combinations listed in Article 4.1.3.2.
3. Crane runway structures shall be designed to resist a horizontal force applied normal to the top of the rails equal to not less than 20% of the sum of the weights of the lifted load and the crane trolley (excluding other parts of the crane).
4. The force described in Sentence (3) shall be equally distributed on each side of the runway and shall be assumed to act in either direction.
5. Crane runway structures shall be designed to resist a horizontal force applied parallel to the top of the rails equal to not less than 10% of the maximum wheel loads of the crane.

Table 4.1.5.11.
Factors for the Calculation of Impact Loads
Forming Part of Sentence 4.1.5.11.(1)

Notes to Table 4.1.5.11.:
(1) See ASME A17.1/CSA B44, "Safety Code for Elevators and Escalators."

1. Bleacher seats shall be designed for a uniformly distributed live load of 1.75 kN for each linear metre or for a concentrated load of 2.2 kN distributed over a length of 0.75 m, whichever produces the most critical effect on the supporting members.
2. Bleachers shall be checked by the erector after erection to ensure that all structural members, including bracing specified in the design, have been installed.
3. Telescopic bleachers shall be provided with locking devices to ensure stability while in use.

1. Helicopter landing areas on roofs shall be constructed in conformance with the requirements for heliports contained in TC SOR/96-433, "Canadian Aviation Regulations - Part III."

1. The minimum specified horizontal load applied outward at the minimum required height of every required guard shall be
   1. 3.0 kN/m for open viewing stands without fixed seats and for means of egress in grandstands, stadia, bleachers and arenas,
   2. a concentrated load of 1.0 kN applied at any point, so as to produce the most critical effect, for access ways to equipment platforms, contiguous stairs and similar areas where the gathering of many people is improbable, and
   3. 0.75 kN/m or a concentrated load of 1.0 kN applied at any point so as to produce the most critical effect, whichever governs for locations other than those described in Clauses (a) and (b).
2. The minimum specified horizontal load applied inward at the minimum required height of every required guard shall be half that specified in Sentence (1).
3. Individual elements within the guard, including solid panels and pickets, shall be designed for a load of 0.5 kN applied outward over an area of 100 mm by 100 mm located at any point in the element or elements so as to produce the most critical effect.
4. The size of the opening between any two adjacent vertical elements within a guard shall not exceed the limits required by Part 3 when each of these elements is subjected to a specified live load of 0.1 kN applied in opposite directions in the in-plane direction of the guard so as to produce the most critical effect.
5. The loads required in Sentence (3) need not be considered to act simultaneously with the loads provided for in Sentences (1), (2) and (6).
6. The minimum specified load applied vertically at the top of every required guard shall be 1.5 kN/m and need not be considered to act simultaneously with the horizontal load provided for in Sentence (1).
7. Handrails and their supports shall be designed and constructed to withstand the following loads, which need not be considered to act simultaneously:
   1. a concentrated load not less than 0.9 kN applied at any point and in any direction for all handrails, and
   2. a uniform load not less than 0.7 kN/m applied in any direction to handrails not located within dwelling units.

1. Vehicle guardrails shall be designed for a concentrated load of 22 kN applied horizontally outward at any point 500 mm above the floor surface so as to produce the most critical effect. (See Note A-4.1.5.14. and 4.1.5.15.(1).)
2. The loads required in Sentence (1) need not be considered to act simultaneously with the loads provided for in Article 4.1.5.14.

1. Where the floor elevation on one side of a wall, including a wall around a shaft, is more than 600 mm higher than the elevation of the floor or ground on the other side, the wall shall be designed to resist the appropriate outward lateral design loads prescribed elsewhere in Subsection 4.1.5. or 0.5 kPa acting outward, whichever produces the more critical effect.

1. Firewalls shall be designed to resist the maximum effect due to
   1. the appropriate lateral design loads prescribed elsewhere in this Section, or
   2. a factored lateral load of 0.5 kPa under fire conditions, as described in Sentence (2).
2. Under fire conditions, where the fire-resistance rating of the structure is less than that of the firewall,
   1. lateral support shall be assumed to be provided by the structure on one side only, or
   2. another structural support system capable of resisting the loads imposed by a fire on either side of the firewall shall be provided.