Subsection 1028.6 - Width of means of egress for assembly The clear width of aisles and other means of egress shall comply with Section 1028.6.1 where smoke-protected seating is not provided and with Section 1028.6.2 or 1028.6.3 where smoke-protected seating is provided. The clear width shall be measured to walls, edges of seating and tread edges except for permitted projections.
1028.6.1Without smoke protection. The clear width of the means of egress shall provide sufficient capacity in accordance with all of the following, as applicable:1. At least 0.3 inch (7.6 mm) of width for each occupant served shall be provided on stairs having riser heights 7 inches (178 mm) or less and tread depths 11 inches (279 mm) or greater, measured horizontally between tread nosings.2. At least 0.005 inch (0.127 mm) of additional stair width for each occupant shall be provided for each 0.10 inch (2.5 mm) of riser height above 7 inches (178 mm).3. Where egress requires stair descent, at least 0.075 inch (1.9 mm) of additional width for each occupant shall be provided on those portions of stair width having no handrail within a horizontal distance of 30 inches (762 mm).4. Ramped means of egress, where slopes are steeper than one unit vertical in 12 units horizontal (8-percent slope), shall have at least 0.22 inch (5.6 mm) of clear width for each occupant served. Level or ramped means of egress, where slopes are not steeper than one unit vertical in 12 units horizontal (8-percent slope), shall have at least 0.20 inch (5.1 mm) of clear width for each occupant served.1028.6.2 Smoke-protected seating. The clear width of the means of egress for smoke-protected assembly seating shall not be less than the occupant load served by the egress element multiplied by the appropriate factor in Table 1028.6.2. The total number of seats specified shall be those within the space exposed to the same smoke-protected environment. Interpolation is permitted between the specific values shown. A life safety evaluation, complying with NFPA 101, shall be done for a facility utilizing the reduced width requirements of Table 1028.6.2 for smoke-protected assembly seating. Exception: For an outdoor smoke-protected assembly with an occupant load not greater than 18,000, the clear width shall be determined using the factors in Section 1028.6.3.
TABLE 1028.6.2 WIDTH OF AISLES FOR SMOKE-PROTECTED ASSEMBLY
| TOTAL NUMBER OFSEATS IN THE SMOKE- PROTECTED ASSEMBLY OCCUPANCY | INCHES OF CLEAR PER SEAT SERVED |
| Stairs and aisle steps with handrails within 30 inches | Stairs and aisle steps without handrailswithin 30 inches | Passageways, doorways and ramps not steeper than 1 in 10 in slope | Ramps steeperthan 1 in 10 in slope |
| Equal to or less than 5,000 | 0.200 | 0.250 | 0.150 | 0.165 |
| 10,000 | 0.130 | 0.163 | 0.100 | 0.110 |
| 15,000 | 0.096 | 0.120 | 0.070 | 0.077 |
| 20,000 | 0.076 | 0.095 | 0.056 | 0.062 |
| Equal to or greater than 25,000 | 0.060 | 0.075 | 0.044 | 0.048 |
| For SI: 1 inch = 25.4 mm. |
1028.6.2.1Smoke control.Means of egress serving a smoke-protected assembly seating area shall be provided with a smoke control system complying with Section 909 or natural ventilation designed to maintain the smoke level at least 6 feet (1829 mm) above the floor of the means of egress.1028.6.2.2Roof height. A smoke-protected assembly seating area with a roof shall have the lowest portion of the roof deck not less than 15 feet (4572 mm) above the highest aisle or aisle accessway. Exception: A roof canopy in an outdoor stadium shall be permitted to be less than 15 feet (4572 mm) above the highest aisle or aisle accessway provided that there are no objects less than 80 inches (2032 mm) above the highest aisle or aisle accessway.
1028.6.2.3Automatic sprinklers. Enclosed areas with walls and ceilings in buildings or structures containing smoke-protected assembly seating shall be protected with an approved automatic sprinkler system in accordance with Section 903.3.1.1. Exceptions:
1. The floor area used for contests, performances or entertainment provided the roof construction is more than 50 feet (15 240 mm) above the floor level and the use is restricted to low fire hazard uses.2. Press boxes and storage facilities less than 1,000 square feet (93 m2) in area.3. Outdoor seating facilities where seating and the means of egress in the seating area are essentially open to the outside.1028.6.3Width of means of egress for outdoor smoke-protected assembly. The clear width in inches (mm) of aisles and other means of egress shall be not less than the total occupant load served by the egress element multiplied by 0.08 (2.0 mm) where egress is by aisles and stairs and multiplied by 0.06 (1.52 mm) where egress is by ramps, corridors, tunnels or vomitories. Exception: The clear width in inches (mm) of aisles and other means of egress shall be permitted to comply with Section 1028.6.2 for the number of seats in the outdoor smoke-protected assembly where Section 1028.6.2 permits less width.