Means of Egress Part 3 Chapter 4

Exit Accesses: portion of means of egress that leads to an exit. Doors Stairs Ramps Corridors Aisles & Accessways

Exit Accesses: portion of means of egress that leads to an exit. Doors: 32” clear inside width (36” door) Swings in direction of travel, but cannot reduce stir landing dimensions or corridor width by more than 7” when fully open Increase swing of door Create an alcove Enlarge the landing Possibly use sliding door Must meet ADA guidelines Less than 50 occupants – door can swing into the space Thresholds must be same elevation as finished floor or within ½” Transition must be beveled if between ¼” and ½” (ADA, ICC/ANSI)

Exit Accesses: portion of means of egress that leads to an exit. Stairs: Exit access stairs are not the same as exit stairs Exit access stairs: located when one tenant is located on multiple floors of a building or when there is a mezzanine within a space All stairs must meet a set of code requirements Treads & risers Top & bottom landings Handrails Typically required on both sides, and extend beyond the top & bottom of the stairway with an un-interrupted grip Guards Railings used to prevent people from falling off when there are changes in elevation (over 30”) Typically 42” high – must be mounted at required height for a handrail

Exit Accesses: portion of means of egress that leads to an exit. Ramps: Slope ratio: maximum ratio = 1:12 1 unit vertical distance to 12 units horizontal distance 36” wide, typically, measured to inside of handrail Handrail & guard requirements are similar to stairs Width & clearance requirements are similar to corridors Landings: allow for 60” turn-around Typically required every rise of 30”

Exit Accesses: portion of means of egress that leads to an exit. Corridors: required to be enclosed 44” width minimum, but is dependant on codes for specific occupancy classification/load

Exit Accesses: portion of means of egress that leads to an exit. Aisles & Aisle Accessways: created by furniture or equipment Moveable or fixed seating/furniture

Exits: Located at the end of an exit access, it is fully enclosed & rated. Exterior Exit Door Exit Stairs Most common type of exit – must be constructed of rated assemblies Doors must swing in direction of exit discharge Horizontal Exits Protected exit to a safe area of refuge – no change in level Exit Passageways Type of horizontal passage or corridor that provides the same level of protection as an exit stair

Areas of Refuge Where one or more people can wait safely for assistance during an emergency Required to be enclosed by fire and/or smoke partitions Most common requirement: one space for every 200 occupants Typically 30” x 48” If using NFPA & LSC: areas of refuge are not required if building is sprinklered If using IBC: all buildings are required to have an accessible means of egress Sometimes the jurisdiction of a project includes the requirement of both the IBC and LSC – you may have to consult with a code official

Exit Discharge: part of a means of egress that connects an exit with a public way. Main Lobby Foyer or Vestibule Discharge Corridor Egress Court Small Alley or Sidewalk

Means of Egress Capacity Number of Exits Refer to Tables in textbook & previous lectures 2. Exit Widths Refer to Table 1005.1 and additional requirements (on next slide) 3. Arrangement of Exits Half-diagonal rule, travel distance, dead-end corridors, common path of travel 4. Signage Exit signs & other signs

Means of Egress Capacity: Exit Widths Minimum clear door widths: Inside dim of 32”(standard 36” door) Maximum door widths: No more than 48” per door leaf (must spec more than one door) More than one exit: Can affect width of exit access (OL /# of exits) Minimum exit discharge widths: Exit discharge width cannot be less than width of the exit it leads from Minimum corridor widths: Never less than 36”, typical minimum is 44”-48” Exiting from basement: Ground floor OL is increased to reflect basement OL to allow for exiting Minimum horizontal exit sizes: Horizontal areas of refuge must be large enough to hold own occupants plus those from the “fire side” Unobstructed paths: Non-structural wall applications <1/2”, wall sconces & other devices <4”, doors <7” 50 percent rule: Expected loss of any one exit location cannot reduce the total capacity of the exit width by more than 50% Aisles & aisle accessways: 36”-44” minimum width

Signage Exit signs Typically required whenever a floor or space has two or more exits Must be located at doors of all stair enclosures, exit passageways, horizontal exits, all exterior exit doors, & any space where the direction of egress in unclear Typically, no point within the exit access can be more than 100’ from the nearest visible sign Refer to building codes, LSC, ADA, and NFPA 170