ICC Subscriptions
 
SECTION 1607 LIVE LOADS

1607.1 General.
Live loads are those loads defined in Section 1602.1.

TABLE 1607.1 MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, Lo, AND MINIMUM CONCENTRATED LIVE LOADSg



OCCUPANCY OR USE
UNIFORM (psf)
CONCENTRATED (lbs.)
1. Apartments (see residential)
-
-
2. Access floor systems    
Office use
50
2,000
Computer use
100
2,000
3. Armories and drill rooms
150
-
4. Assembly areas and theaters  
-
Fixed seats (fastened to floor)
60
Follow spot, projections and control rooms
50
Lobbies
100
Movable seats
100
Stages and platforms
125
Other assembly areas
100
5. Balconies (exterior) and decksh
Same as occupancy served
-
6. Bowling alleys
75
-
7. Catwalks
40
300
8. Cornices
60
-
9. Corridors, except as otherwise indicated
100
-
10. Dance halls and ballrooms
100
-
11. Dining rooms and restaurants
100
-
12. Dwellings (see residential)
-
-
13. Elevator machine room grating (on area of 4 in2)
-
300
14. Finish light floor plate construction (on area of 1 in2)
-
200
15. Fire escapes
100
-
          On single-family dwellings only
40
16. Garages (passenger vehicles only)
          Trucks and buses 
40
Note a
See Section 1607.6
17. Grand stands
     (see stadium and arena bleachers)
-
-
18. Gymnasiums, main floors and balconies
100
-
19. Handrails, guards and grab bars
See Section 1607.7
20. Hospitals    
Corridors above first floor
80
1,000
Operating rooms, laboratories
60
1,000
Patient rooms
40
1,000
21. Hotels (see residential)
-
-
22. Libraries    
  Corridors above first floor
80
1,000
  Reading rooms
60
1,000
  Stack rooms
150b
1,000


TABLE 1607.1-MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, Lo, AND MINIMUM CONCENTRATED LIVE LOADSg


OCCUPANCY OR USE
UNIFORM
(psf)
CONCENTRATED
(lbs.)
23. Manufacturing    
Heavy
250
3,000
Light
125
2,000
24. Marquees
75
-
25. Office buildings    
Corridors above first floor
80
2,000
File and computer rooms shall be designed for heavier loads based on anticipated occupancy
-
-
Lobbies and first-floor corridors
100
2,000
Offices
50
2,000
26. Penal institutions    
Cell blocks
40
-
Corridors
100
 
27. Residential    
One- and two-family dwellings    
Uninhabitable attics without storagei
10
 
Uninhabitable attics with limited
storagei, j, k
20
 
Habitable attics and sleeping areas
30
-
All other areas
40
 
Hotels and multifamily dwellings    
Private rooms and corridors serving them
40
 
Public rooms and corridors serving
them
100
 
28. Reviewing stands, grand stands and bleachers
Note c
29. Roofs    
All roof surfaces subject to maintenance workers  
300
Awnings and canopies    
Fabric construction supported by a light weight rigid skeleton structure
5
 
All other construction
nonreducible
 
Ordinary flat, pitched, and curved roofs
20
 
Primary roof members, exposed to a work floor
20
 
Single panel point of lower chord of roof trusses or any point along primary structural members supporting roofs:    
Over manufacturing, storage ware houses, and repair garages  
2,000
All other occupancies  
300
Roofs used for other special purposes
Note 1
Note 1
Roofs used for promenade purposes
60
 
Roofs used for roof gardens or assembly purposes
100
 
30. Schools    
Classrooms
40
1,000
Corridors above first floor
80
1,000
First-floor corridors
100
1,000
31. Scuttles, skylight ribs and accessible ceilings
-
200
32. Sidewalks, vehicular drive ways and yards, subject to trucking
250d
8,000e
33. Skating rinks
100
-


TABLE 1607.1-MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, Lo, AND MINIMUM CONCENTRATED LIVE LOADSg


OCCUPANCY OR USE
UNIFORM
(psf)
CONCENTRATED (lbs.)
34. Stadiums and arenas
Bleachers
100c
-
Fixed seats (fastened to floor)
60c
35. Stairs and exits
Note f
One- and two-family dwellings
40
All other
100
36. Storage warehouses  
(shall be designed for heavier loads if required for anticipated storage)
Heavy
250
Light
125
37. Stores
Retail
First floor
100
1,000
Upper floors
75
1,000
Wholesale, all floors
125
1,000
38. Vehicle barrier systems
See Section 1607.7.3
39. Walkways and elevated platforms
          (other than exitways)
60
-
40. Yards and terraces, pedestrians
100
-

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square inch = 645.16 mm2, 1 square foot = 0.0929 m2, 1 pound per square foot = 0.0479 kN/m2, 1 pound = 0.004448 kN,


a. Floors in garages or portions of buildings used for the storage of motor vehicles shall be designed for the uniformly distributed live loads of Table 1607.1 or the following concentrated loads: (1) for garages restricted to passenger vehicles accommodating not more than nine passengers, 3,000 pounds acting on an area of 4.5 inches by 4.5 inches; (2) for mechanical parking structures without slab or deck which are used for storing passenger vehicles only, 2,250 pounds per wheel.


b. The loading applies to stack room floors that support nonmobile, double-faced library bookstacks, subject to the following limitations:


1. The nominal bookstack unit height shall not exceed 90 inches;


2. The nominal shelf depth shall not exceed 12 inches for each face; and


3. Parallel rows of double-faced bookstacks shall be separated by aisles not less than 36 inches wide.


c. Design in accordance with ICC 300.


d. Other uniform loads in accordance with an approved method which contains provisions for truck loadings shall also be considered where appropriate.


e. The concentrated wheel load shall be applied on an area of 4.5 inches by 4.5 inches.


f. Minimum concentrated load on stair treads (on area of 4 square inches) is 300 pounds.


g. Where snow loads occur that are in excess of the design conditions, the structure shall be designed to support the loads due to the increased loads caused by drift buildup or a greater snow design determined by the building official (see Section 1608). For special-purpose roofs, see Section 1607.11.2.2.


h. See Section 1604.8.3 for decks attached to exterior walls.


i. Attics without storage are those where the maximum clear height between the joist and rafter is less than 42 inches, or where there are not two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide, or greater, located within the plane of the truss. For attics without storage, this live load need not be assumed to act concurrently with any other live load requirements.


j. For attics with limited storage and constructed with trusses, this live load need only be applied to those portions of the bottom chord where there are two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide or greater, located within the plane of the truss. The rectangle shall fit between the top of the bottom chord and the bottom of any other truss member, provided that each of the following criteria is met:


i. The attic area is accessible by a pull-down stairway or framed opening in accordance with Section 1209.2, and


ii. The truss shall have a bottom chord pitch less than 2:12.


iii. Bottom chords of trusses shall be designed for the greater of actual imposed dead load or 10 psf, uniformly distributed over the entire span.


k. Attic spaces served by a fixed stair shall be designed to support the minimum live load specified for habitable attics and sleeping rooms.


l. Roofs used for other special purposes shall be designed for appropriate loads as approved by the building official.



1607.2 Loads not specified.
For occupancies or uses not designated in Table 1607.1, the live load shall be determined in accordance with a method approved by the building official.

1607.3 Uniform live loads.
The live loads used in the design of buildings and other structures shall be the maximum loads expected by the intended use or occupancy but shall in no case be less than the minimum uniformly distributed unit loads required by Table 1607.1.

1607.4 Concentrated loads.
Floors and other similar surfaces shall be designed to support the uniformly distributed live loads prescribed in Section 1607.3 or the concentrated load, in pounds (kilonewtons), given in Table 1607.1, whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall be assumed to be uniformly distributed over an area 21/2 feet by 21/2 feet (0.76 m by 0.76 m) [61/4 square feet (0.58 m2)] and shall be located so as to produce the maximum load effects in the structural members.

1607.5 Partition loads.
In office buildings and in other buildings where partition locations are subject to change, provisions for partition weight shall be made, whether or not partitions are shown on the construction documents, unless the specified live load exceeds 80 psf (3.83 kN/m2). The partition load shall not be less than a uniformly distributed live load of 15 psf (0.72 kN/m2).

1607.6 Truck and bus garages.
Minimum live loads for garages having trucks or buses shall be as specified in Table 1607.6, but shall not be less than 50 psf (2.40 kN/m2), unless other loads are specifically justified and approved by the building official. Actual loads shall be used where they are greater than the loads specified in the table.

TABLE 1607.6 UNIFORM AND CONCENTRATED LOADS


LOADING
CLASSa
UNIFORM LOAD
(pounds/linear foot of lane)
CONCENTRATED LOAD
(pounds)b
For moment design
For shear design
H20-44 and HS20-44
640
18,000
26,000
H15-44 and HS15-44
480
13,500
19,500

For SI: 1 pound per linear foot = 0.01459 kN/m, 1 pound = 0.004448 kN, 1 ton = 8.90 kN.


a. An H loading class designates a two-axle truck with a semitrailer. An HS loading class designates a tractor truck with a semitrailer. The numbers following the letter classification indicate the gross weight in tons of the standard truck and the year the loadings were instituted.


b. See Section 1607.6.1 for the loading of multiple spans.



1607.6.1 Truck and bus garage live load application. The concentrated load and uniform load shall be uniformly distributed over a 10-foot (3048 mm) width on a line normal to the centerline of the lane placed within a 12-foot-wide (3658 mm) lane. The loads shall be placed within their individual lanes so as to produce the maximum stress in each structural member. Single spans shall be designed for the uniform load in Table 1607.6 and one simultaneous concentrated load positioned to produce the maximum effect. Multiple spans shall be designed for the uniform load in Table 1607.6 on the spans and two simultaneous concentrated loads in two spans positioned to produce the maximum negative moment effect. Multiple span design loads, for other effects, shall be the same as for single spans.
1607.7 Loads on handrails, guards, grab bars, seats and vehicle barrier systems. Handrails, guards, grab bars, accessible seats, accessible benches and vehicle barrier systems shall be designed and constructed to the structural loading conditions set forth in this section.

1607.7.1 Handrails and guards. Handrails and guards shall be designed to resist a load of 50 pounds per linear foot (plf) (0.73 kN/m) applied in any direction at the top and to transfer this load through the supports to the structure. Glass handrail assemblies and guards shall also comply with Section 2407.

Exceptions:
1. For one- and two-family dwellings, only the single concentrated load required by Section 1607.7.1.1 shall be applied.
2. In Group I-3, F, H and S occupancies, for areas that are not accessible to the general public and that have an occupant load less than 50, the minimum load shall be 20 pounds per foot (0.29 kN/m).
1607.7.1.1 Concentrated load. Handrails and guards shall be able to resist a single concentrated load of 200 pounds (0.89 kN), applied in any direction at any point along the top, and to transfer this load through the supports to the structure. This load need not be assumed to act concurrently with the loads specified in Section 1607.7.1.
1607.7.1.2 Components. Intermediate rails (all those except the handrail), balusters and panel fillers shall be designed to withstand a horizontally applied normal load of 50 pounds (0.22 kN) on an area equal to 1 square foot (0.0929 m2), including openings and space between rails. Reactions due to this loading are not required to be superimposed with those of Section 1607.7.1 or 1607.7.1.1.
1607.7.2 Grab bars, shower seats and dressing room bench seats. Grab bars, shower seats and dressing room bench seat systems shall be designed to resist a single concentrated load of 250 pounds (1.11 kN) applied in any direction at any point.
1607.7.3 Vehicle barrier systems. Vehicle barrier systems for passenger vehicles shall be designed to resist a single load of 6,000 pounds (26.70 kN) applied horizontally in any direction to the barrier system and shall have anchorage or attachment capable of transmitting this load to the structure. For design of the system, two loading conditions shall be analyzed. The first condition shall apply the load at a height of 1 foot, 6 inches (457 mm) above the floor or ramp surface. The second loading condition shall apply the load at 2 feet, 3 inches (686 mm) above the floor or ramp surface. The more severe load condition shall govern the design of the barrier restraint system. The load shall be assumed to act on an area not to exceed 1 square foot (0.0929 m2), and is not required to be assumed to act concurrently with any handrail or guard loadings specified in Section 1607.7.1. Garages accommodating trucks and buses shall be designed in accordance with an approved method that contains provisions for traffic railings.
1607.8 Impact loads. The live loads specified in Section 1607.3 include allowance for impact conditions. Provisions shall be made in the structural design for uses and loads that involve unusual vibration and impact forces.

1607.8.1 Elevators. Elevator loads shall be increased by 100 percent for impact and the structural supports shall be designed within the limits of deflection prescribed by ASME A17.1.
1607.8.2 Machinery. For the purpose of design, the weight of machinery and moving loads shall be increased as follows to allow for impact: (1) elevator machinery, 100 percent; (2) light machinery, shaft- or motor-driven, 20 percent; (3) reciprocating machinery or power-driven units, 50 percent; (4) hangers for floors or balconies, 33 percent. Percentages shall be increased where specified by the manufacturer.
1607.9 Reduction in live loads. Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607.1 are permitted to be reduced in accordance with Section 1607.9.1 or 1607.9.2. Roof uniform live loads, other than special purpose roofs of Section 1607.11.2.2, are permitted to be reduced in accordance with Section 1607.11.2. Roof uniform live loads of special purpose roofs are permitted to be reduced in accordance with Section 1607.9.1 or 1607.9.2.

1607.9.1 General. Subject to the limitations of Sections 1607.9.1.1 through 1607.9.1.4, members for which a value of KLLAT is 400 square feet (37.16 m2) or more are permitted to be designed for a reduced live load in accordance with the following equation:



(Equation 16-22)

For SI:


where:
 
L    =    Reduced design live load per square foot (square meter) of area supported by the member.
     
Lo    =    Unreduced design live load per square foot (square meter) of area supported by the member (see Table 1607.1).
     
KLL    =    Live load element factor (see Table 1607.9.1).
     
AT    =    Tributary area, in square feet (square meters).
     
L shall not be less than 0.50 Lo for members supporting one floor and L shall not be less than 0.40 Lo for members supporting two or more floors.

TABLE 1607.9.1 LIVE LOAD ELEMENT FACTOR, KLL

 

ELEMENT
KLL
Interior columns
Exterior columns without cantilever slabs
4
4
Edge columns with cantilever slabs
3
Corner columns with cantilever slabs
Edge beams without cantilever slabs
Interior beams
2
2
2
All other members not identified above including:
1
  Edge beams with cantilever slabs
Cantilever beams
One-way slabs
Two-way slabs
Members without provisions for continuous shear
transfer normal to their span
1607.9.1.1 One-way slabs. The tributary area, AT, for use in Equation 16-22 for one-way slabs shall not exceed an area defined by the slab span times a width normal to the span of 1.5 times the slab span.
1607.9.1.2 Heavy live loads. Live loads that exceed 100 psf (4.79 kN/m2) shall not be reduced.

Exceptions:
1. The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607.9.1.
2. For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.
1607.9.1.3 Passenger vehicle garages. The live loads shall not be reduced in passenger vehicle garages.

Exception:
The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607.9.1.
1607.9.1.4 Group A occupancies. Live loads of 100 psf (4.79 kN/m2) and at areas where fixed seats are located shall not be reduced in Group A occupancies.
1607.9.1.5 Roof members. Live loads of 100 psf (4.79 kN/m2) or less shall not be reduced for roof members except as specified in Section 1607.11.2.
1607.9.2 Alternate floor live load reduction. As an alternative to Section 1607.9.1, floor live loads are permitted to be reduced in accordance with the following provisions. Such reductions shall apply to slab systems, beams, girders, columns, piers, walls and foundations.
1. A reduction shall not be permitted in Group A occupancies.
2. A reduction shall not be permitted where the live load exceeds 100 psf (4.79 kN/m2) except that the design live load for members supporting two or more floors is permitted to be reduced by 20 percent.

Exception:
For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.
3. A reduction shall not be permitted in passenger vehicle parking garages except that the live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent.
4. For live loads not exceeding 100 psf (4.79 kN/m2), the design live load for any structural member supporting 150 square feet (13.94 m2) or more is permitted to be reduced in accordance with Equation 16-23.
5. For one-way slabs, the area, A, for use in Equation 16-23 shall not exceed the product of the slab span and a width normal to the span of 0.5 times the slab span.

R = 0.08(A - 150) (Equation 16-23)

For SI: R = 0.861(A - 13.94)

Such reduction shall not exceed the smallest of:
1. 40 percent for horizontal members;
2. 60 percent for vertical members; or
3. R as determined by the following equation.

R = 23.1(1 + D/Lo) (Equation 16-24)

where:
 
A    =    Area of floor supported by the member, square feet (m2).
 
D    =    Dead load per square foot (m2) of area supported.
 
Lo    =    Unreduced live load per square foot (m2) of area supported.
 
R    =    Reduction in percent.

1607.10 Distribution of floor loads. Where uniform floor live loads are involved in the design of structural members arranged so as to create continuity, the minimum applied loads shall be the full dead loads on all spans in combination with the floor live loads on spans selected to produce the greatest effect at each location under consideration. It shall be permitted to reduce floor live loads in accordance with Section 1607.9.

1607.11 Roof loads.
The structural supports of roofs and marquees shall be designed to resist wind and, where applicable, snow and earthquake loads, in addition to the dead load of construction and the appropriate live loads as prescribed in this section, or as set forth in Table 1607.1. The live loads acting on a sloping surface shall be assumed to act vertically on the horizontal projection of that surface.

1607.11.1 Distribution of roof loads. Where uniform roof live loads are reduced to less than 20 psf (0.96 kN/m2) in accordance with Section 1607.11.2.1 and are applied to the design of structural members arranged so as to create continuity, the reduced roof live load shall be applied to adjacent spans or to alternate spans, whichever produces the most unfavorable load effect. See Section 1607.11.2 for reductions in minimum roof live loads and Section 7.5 of ASCE 7 for partial snow loading.
1607.11.2 Reduction in roof live loads. The minimum uniformly distributed live loads of roofs and marquees, Lo, in Table 1607.1 are permitted to be reduced in accordance with Section 1607.11.2.1 or 1607.11.2.2.
1607.11.2.1 Flat, pitched and curved roofs. Ordinary flat, pitched and curved roofs, and awnings and canopies other than of fabric construction supported by lightweight rigid skeleton structures, are permitted to be designed for a reduced roof live load as specified in the following equations or other controlling combinations of loads in Section 1605, whichever produces the greater load.

In structures such as greenhouses, where special scaffolding is used as a work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equations shall not be used unless approved by the building official. Such structures shall be designed for a minimum roof live load of 12 psf (0.58 kN/m2).
Lr = Lo R1R2 (Equation 16-25)

where: 12 ≤ Lr ≤ 20

For SI: Lr = LoR1R2

where: 0.58 ≤ Lr ≤ 0.96

L
r = Reduced live load per square foot (m2) of horizontal projection in pounds per square foot (kN/m2).

The reduction factors R1 and R2 shall be determined as follows:

R1 = 1 for At ≤ 200 square feet (18.58 m2) (Equation 16-26)

R1 = 1.2 - 0.001At for 200 square feet < At < 600 square feet (Equation 16-27)

For SI: 1.2 - 0.011At for 18.58 square meters < At < 55.74 square meters

R1 = 0.6 for At ≥ 600 square feet (55.74 m2) (Equation 16-28)

where:

A
t = Tributary area (span length multiplied by effective width) in square feet (m2) supported by any structural member, and

R2 = 1 for F ≤ 4 (Equation 16-29)

R2 = 1.2 - 0.05 F for 4 < F < 12 (Equation 16-30)

R2 = 0.6 for F ≥ 12 (Equation 16-31)

where:

F
= For a sloped roof, the number of inches of rise per foot (for SI: F = 0.12 × slope, with slope expressed as a percentage), or for an arch or dome, the rise-to-span ratio multiplied by 32.
1607.11.2.2 Special-purpose roofs. Roofs used for promenade purposes, roof gardens, assembly purposes or other special purposes, and marquees, shall be designed for a minimum live load, Lo, as specified in Table 1607.1. Such live loads are permitted to be reduced in accordance with Section 1607.9. Live loads of 100 psf (4.79 kN/m2) or more at areas of roofs classified as Group A occupancies shall not be reduced.
1607.11.3 Landscaped roofs. Where roofs are to be landscaped, the uniform design live load in the landscaped area shall be 20 psf (0.958 kN/m2). The weight of the landscaping materials shall be considered as dead load and shall be computed on the basis of saturation of the soil.
1607.11.4 Awnings and canopies. Awnings and canopies shall be designed for uniform live loads as required in Table 1607.1 as well as for snow loads and wind loads as specified in Sections 1608 and 1609.
1607.12 Crane loads. The crane live load shall be the rated capacity of the crane. Design loads for the runway beams, including connections and support brackets, of moving bridge cranes and monorail cranes shall include the maximum wheel loads of the crane and the vertical impact, lateral and longitudinal forces induced by the moving crane.

1607.12.1 Maximum wheel load. The maximum wheel loads shall be the wheel loads produced by the weight of the bridge, as applicable, plus the sum of the rated capacity and the weight of the trolley with the trolley positioned on its runway at the location where the resulting load effect is maximum.
1607.12.2 Vertical impact force. The maximum wheel loads of the crane shall be increased by the percentages shown below to determine the induced vertical impact or vibration force:

  Monorail cranes (powered) 25 percent
     
  Cab-operated or remotely operated bridge cranes (powered) 25 percent
     
  Pendant-operated bridge cranes (powered) 10 percent
     
  Bridge cranes or monorail cranes with hand-geared bridge, trolley and hoist 0 percent
1607.12.3 Lateral force. The lateral force on crane runway beams with electrically powered trolleys shall be calculated as 20 percent of the sum of the rated capacity of the crane and the weight of the hoist and trolley. The lateral force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction perpendicular to the beam, and shall be distributed according to the lateral stiffness of the runway beam and supporting structure.
1607.12.4 Longitudinal force. The longitudinal force on crane runway beams, except for bridge cranes with hand-geared bridges, shall be calculated as 10 percent of the maximum wheel loads of the crane. The longitudinal force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction parallel to the beam.
1607.13 Interior walls and partitions. Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2).

Exception:
Fabric partitions complying with Section 1607.13.1 shall not be required to resist the minimum horizontal load of 5 psf (0.24 kN/m2).

1607.13.1 Fabric partitions. Fabric partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the following load conditions:
1. A horizontal distributed load of 5 psf (0.24 kN/m2) applied to the partition framing. The total area used to determine the distributed load shall be the area of the fabric face between the framing members to which the fabric is attached. The total distributed load shall be uniformly applied to such framing members in proportion to the length of each member.
2. A concentrated load of 40 pounds (0.176 kN) applied to an 8-inch diameter (203 mm) area [50.3 square inches (32 452 mm2)] of the fabric face at a height of 54 inches (1372 mm) above the floor.