Code of Massachusetts Regulations
780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS
Chapter 16 - Structural Design
Section 1607 - LIVE LOADS
Subsection 1607.1 - General

Universal Citation: 780 CMR MA Code of Regs 1607.1
Current through Register 1531, September 27, 2024

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.

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