Chapter 8 - Means of Egress
exit door, enclosures for stairs, exit passageways, horizontal exits, exterior exit stairways and ramps
Examples of exits
- exit access stairways that serve only two stores (other than in group I-2 and I-3) - Exit access stairways for single residential dwelling unit or sleeping unit in Group R1, R2, or R3 - in group B or M occupancies if the buildin gis sprinklers, the area of the floor opening between stories is not greater than twice the horizontal projected area of the stairway and the opning is protected by a draft curtain and closely spaced sprinklers in accordane with NFPA 13 - in occupancies other than Group B and M if the occupancy complies withh all items in previous exception and the floor opening does not connect more than four stories
Exceptions in which stairways are not required to be enclosed:
occupancy and construction type.
Exit access may or may not be protected depending of the specific requirements of the code based on ____ and ____.
A, B, E, F, I-2, I-4, M, S, U
In sprinklered buildings, which occupancy groups' corridors do not have to be fire-resistive rated?
30"
Intermediate handrails are required so that all portions of the stairway width required for egress capacity are within ___ of a handrail.
1000
Four exits are required when the occupant load is greater than ____.
basements, mezzanines
"stories" include ___ but exclude ____
Means of Egress
A continuous and unobstructed path of vertical and horizontal egress travel from any point in a building or structure to a public way
exits
According to the IBC, exterior exit stairways and ramps are considered ____ not exit discharge areas.
rooms, spaces, aisles, interviewing rooms, hallways, corridors, ramps, and doorways.
Examples of exit access:
public way, 10'0"
Any street, alley, or similar parcel of land essentially unobstructed from the ground to the sky that is permanently appropriated to the public for public use and has a clear width of not less than ____.
1-hour, 10, 30
Corridors must be built of ___ construction when serving an occupant load of ___ or more in Group R1 and I occupancies, and when serving an occupant load of ___ or more in other occupancies.
yes, if the door in the lobby is clearly visible, the level of discharge is sprinklered, and the entire area of discharge is separated from areas below by the same fire-resistance rating as for the exit enclosure that opens onto it
Can an exit discharge include a lobby or multistory buildings?
20 minutes smoke and draft control seals
Doors placed in a 1 hour corridor must have a fire rating of at least ___ and include approved _____ around the door
hazardous areas,
Egress doors must be pioted or side-hinged and swing in the direction of travel when serving ____ or areas with an occupant load of ____ or more.
Automatic closers and tested/approved hardware
Egress doors must have ___ and ____.
the common path of travel exceeds the limits given in the code
Even if two exits are not required based on the occupant load, two exits will be required if...
1 or 2 hours
Exits must have fire ratings of either ____.
the actual number of seats + the occupant load of areas in which fixed seating is not installed
For areas with fixed seating, occupant load is determined by
divided the area assigned to a particular use and dividing it by the occupant load factor
For areas without fixed seating, occupant loads are determined by
18"
For fixed seating without dividing arms, the occupant load is base on one person for each ____ of seating lenght
the width of the stair, 48"
For landings, the minimum dimension in the direction of travel must not be less than ____, but need not be more than ____ if the stair is a straight run.
7 3/4", 10"
For residential occupancies and private stairways serving and occupant load less than 10, the max riser may be ___ and the minimum tread may be ____.
24"
For seating booths, the assumed unit is one person for each ____ of booth seat length.
wired glass
Glass in egress doors must be ___.
3/4 hour 25%
Glass may be used in a 1-hour rated corridor walls only if it is listed and labeled as ___ fire-protection rating and the total area does not exceed ___ of the length of the corridor wall of the room that is is separating from the corridor.
stairs, corridors, toilet rooms, mechanical rooms, closets, and interior partition thicknesses.
Gross floor area includes spaces such as
4 1/2"
Handrails may reduce the required means of egress width no more than ____ on each side
4 1/2" max
Handrails on stairs may project into the require width ___ on each side.
One
How many exits are required form a residential basement or second story of a house?
1. stock must be the same hazard classifications as the main retail 2. not more than 50% of the exit access can be through the stockroom 3. the stockroom cannot be subject to locking from the egress side 4. there must be a demarcated aisle with a minimum width of 44"
IBC allows egress to pass through a stockroom that serves a Group M occupancy is the following four conditions are met:
A, B, E, F, I2, I4, M, S, U
If a building is fully sprinklered, corridors in these groups do not have to have a fire rating, so fire-protection-rated doors are not required.
5'0"
If a stairwell is wider than ____ it must have an intermediate handrail
the clear width, not the width of the door.
If doors are part of the require egress width, what width must be used?
there is no limitation
If fire-resistance-rated glazing is used, what is the limitation on the percentage of glazing that may be used?
Occupant load x 0.2" Occupant Load x 0.15"
If the building is equipped with an automatic sprinkler system and an emergency voice/alarm communication system, the min width of exit stairways is ___ and ___ for exit components that aren't stairways.
Each area is calculated with its respective occupant load factor, and then all loads are added together
If there are mixed occupancies or uses, how is the load factor calculated?
- exit passageways - exit stairs
In a 1 hour rated partition, Doors assembly must be 1 hour rated in these locations:
- corridors - smoke barriers
In a 1 hour rated partition, Doors assembly must be 20 minutes rated in the following locations:
- fire partitions - occupancy separations
In a 1 hour rated partition, Doors assembly must be 3/4 hour rated in these locations:
- exit stairs
In a 2 hour rated partition, Doors assembly must be 1 1/2 hour rated in these locations:
2 hours, 1 hour
In buildings four or more stories high, interior exit stairways must be enclosed with ___ rated walls, in buildings less than four stories high, ___ rated construction is required.
48"
Max width of swinging egress doors is ___.
H4, H5, I1, I2, I3, I4, R
Maximum occupant load is 10 for which occupancy types?
S
Maximum occupant load is 29 for which occupancy types?
H1, H2, H3
Maximum occupant load is 3 for which occupancy types?
A, B, E, F, M, U
Maximum occupant load is 49 for which occupancy types?
occupancy of the building, whether or not the building is sprinklered
Maximum travel distances are based on the ____ and ____.
1. The exit access 2. the exit 3. The discharge
Means of egress consists of what three parts?
public way
Means of egress must lead to a _____.
32" clear, 36" door
Minimum clear with of door
80"
Minimum height of egress doors
adjoining or intervening room or spaces, but not through... kitchens, storerooms, rest rooms, closets, or spaces used for similar purposes
Most codes allow a room to have one exit through ______ but not through _____.
1 1/2"
Nonstructural horizontal projections, such as trim and similar decorative features, may project a maximum of ____ horizontally from either side.
A, E, F1, M, R, S1
Occupancy groups whose maximum travel distance is 200 sprinklered, 250 unsprinklered.
B
Occupancy groups whose maximum travel distance is 200 sprinklered, 300 unsprinklered.
F2, S2, U
Occupancy groups whose maximum travel distance is 300 sprinklered, 400 unsprinklered.
occupancy classification
Occupant load is based on ____.
Means of Egress
One of the most important requirements of any building code. Also known as exiting
leaves that collapse under opposing pressure, 6'6" 10'0"
Revolving doors are allowed as egress doors when they have ____ and a diameter of at least ____. There must also be at least one conforming exit door within ____ of the revolving door.
44", 36"
Stairways serving and occupant load of 50 or more must be at least ___ wide. Those serving an occupant load of 49 or less must not be less than ___ wide.
4", 27-80"
Structural elements, such as light fixtures or furnishings, may project no more than ___ horizontally, at a height of _____ above the walking surface.
TRUE
T or F: Foyers, lobbies, and reception rooms constructed as required for corridors (with 1-hour rated wall) are not considered intervening rooms, so occupants can exit through those spaces.
TRUE
T or F: Handrails are required on both sides of the stair
TRUE, however in some cases, the local building official may reduce the occupant load if they determine two areas would not normally be used at once.
T or F: In determining the occupant load, all portions of the building are presumed to be occupied at the same time.
TRUE
T or F: Travel distance is not an issue once the exit has been reached.
TRUE
T or F: fire-rated corridors considered exit access.
Exit Access
That portion of the means of egress that leads to the entrance of an exit.
Occupancy, Sprinklering
The IBC limits the length of dead-end corridors base on___ and ____.
72", 100
The IBC requires that corridors in schools be ___ wide when serving an occupant load of ____ or more.
return to a wall or floor, or terminate in a newel post
The ends of a handrail must _____.
1 1/4", 2"
The gripping portion cannot be less than ____ or more than ____ in cross-sectional dimensions.
4", 7", 11"
The risers of the stair cannot be less than ___ or more than ___, and the tread must be no less than ___.
36", 38" 12" the depth of one tread
The top of the handrail must be between ___ and ___ above the nosing of the treads and extend not less than ___ beyond the top riser and not less than ___ beyond the bottom riser.
1 1/2"
There must be a space at least ____ wide between the wall and the handrail.
501 and 1000
Three exits are required when the occupant load is between ___ and ____.
gasketing or intumescent material
To meet the requirement of positive pressure fire testing, a door must have ____ or ____ along its edge or frame
1. Occupant load and occupancy of a space 2. Limitations on the common path of egress travel 3. specific requirements when large occupant loads are encountered
What determines the number of exits or exit access doorways?
R2 and R3 (apts and condos) - only one exit is permitted when the occupant load is 20 or less.
What is the one exception to the two exit requirements?
exit access
What is the portion of the building where travel distance is measured and regulated?
their own occupant load, the occupant load of the accessory space
When an occupant load from an accessory space exits through a primary space, the egress facilities from the primary space occupant load must include ____ plus _____.
all occupancies if the load is 10 or less, other than H
When are sliding doors permitted as a means of egress
when the number of occupants of a space exceeds the number given in the code
When are two exits required?
when there is an assembly occupancy (with a very low occupant load factor) or a very large space
When should exit width be verified?
Stair
a change in elevation consisting of one or more risers
Interior exit stairway, Interior exit ramp
an exit component that serves to meet one or more means-of-egress reqruirements
panic hardware
hardware that unlatches the door when pressure is applied against it rather than requiring a turning motion as with a doorknob or lever handle.
Exit access stairway
interior stairway that is not a required interior exit stairway, such as a monumental stair serving two floors of a retail store
intumescent material
material that swells and chars when exposed to heat to form a barrier to smoke and fire
Stairways
one of more flights of stairs, with the necessary landings and platforms connecting them, forming a continuous passage from one level to another
Corridor
portion of an exit access leading to an exit. Purpose is to provide a safe means of egress from a room or space to a building exit or another approved exitway, such as a stairway.
Exit Discharge
portion of the egress system between the termination of an exit and a public way. Typically include portions outside the exterior walls such as exterior exit balconies, exterior exit stairways, and exit courts.
Positive pressure fire testing
simulates actual fire conditions where there is positive pressure on the fire side of the door above a certain point on the door and negative pressure below this point. Under such conditions, there is a greater tendency for smoke and gases to be forced through the crack between the door and frame.
Occupant load factor
the amount of floor area presumed to be occupied by one person. Based on the generic function of building spaces and is not the same as the occupancy groups
Travel Distance
the distance that an occupant must travel from the most remote point in the occupied portions of the exit access to the entrance to the nearest exit.
Occupant load
the number of people that a building code assumes will occupy a given building or portion of a building.
Common path of egress travel
the portion of an exit access that the occupants are required to traverse before two separate and distinct paths of egress travel to two exits become available
Exit
the portion of the egress system that provides a protected path of egress between the exit access and the exit discharge. Full enclosed and protected from all other interior spaces by fire-resistance-rated construction with protected openings
Occupant load x 0.3" Occupant Load x 0.2"
the required minimum width of exit stairways is ____ and ___ for exit components that aren't stairways.
Rise
the vertical component that connects two treads
