PX- Chapter 8: Means of Egress Flashcards
define 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
List (do not describe yet) the parts of egress (the progression through exiting)
- Exit Access
- Exit
- Exit Discharge
- this leads to a public way
what is a exit access
portion that leads to the entrance of an exit- may or may not be protected depending on occupancy and construction type.
includes things like rooms, aisles, hallways, corridors, fire rated corridors
what is an exit
provides a protected path between the exit access and the exit discharge.
fully enclosed and protected.
once you reach the exit, travel distance is not an issue
what is the exit discharge
between the termination of an exit and a public way like exterior exit stairways and exit courts, could be a lobby, exterior ramps
what is the public way
any street, alley or similar parcel of land that is unobstructed from the ground to the sky and that is permanently appropriated to the public for public use and is no less than 10’ wide.
what is the occupant load
the number of people that the building code assumes will occupy a given building or portion of a building.
based on occupancy classification
what does the occupant load assume about different spaces
that different types of use in a space will be more densely packed with people than others and that exiting provisions should designed accordingly
example- auditorium has more people than an office space of the same area
what is the occupant load factor
the amount of floor area presumed to be occupied by one person- not based on ergonomics or proxemics but on generic functions of spaces
what is the gross floor area when it comes to occupant loads
floor area including stairs, corridors, toilet rooms, mechanical rooms, closets and interior partition thicknesses
what does net area refer to when referring to occupant load
just the space actually used
why must you have two exits in some spaces
to have an alternate way out of a room if one exit is blocked
what is the max occupant load in most occupancy categories (minus R) before you need 2 exits
49
what is the max occupancy load for apartments and condos before you need two exits
20
besides occupant load, what other factor might determine if you need 2 or more exits
the common path of egress travel exceeds code (which varies based on occupancy category and if it’s sprinklered or not.
how do you calculate occupant load
you are given square footage
- find out which type of occupancy the space is- like assembly with out fixed seats
- look at the table, find what type it is and look at the occupant load factor given
- divide the square footage by the occupant load factor and ta da!
why do you need to have two exits a certain distance away from each other
so that both exits will not be blocked by the fire or emergency.
how do you find out the minimum distance of exits when two exits are required
find the diagonal length of the room and divide in two. so a room that is 50 feet long , the doors need to be 25’ apart or 1/3 the distance if sprinklered
what is the travel distance in egress
the distance traveled from the most remote point in the space to the nearest exit (usually stairs in a highrise)
what are maximum travel distances based on
the occupancy of the building and if the building is sprinklered
what is the maximum exit access travel distance for most occupancy types
200’ with out sprinkler and 150 feet with sprinklers except business is 200 & 300. Institutional is not allowed to not have sprinklers and is 200’ with.
what types of spaces are you not allowed to exit through for egress
kitchen, store rooms, restrooms, closets. Can’t exit a bedroom through a closet or bathroom unless it’s a residential space with a OL of less than 50
how do you determined the minimum width of exits
multiplying the occupand load by 0.3 inches for stairs and 0.2 inches for all other egress components- however it can’t be less than elsewhere in the code (like a corridor can’t be less than 44” wide and exit doors can’t be less than 32” wide- stairs can’t be less than 36” wide for OL of 49 or less). This also changes if two or more exits are required
door width is the clear door space when the door is open to 90 degrees
safe to go with minimum 36” exit door and have two exits
what is the minimum corridor width for occupancies greater than 50 and less than 50
more than 50 is 44” and less than 50 is 36”
how far in to the corridor can trim project
1.5” max
what is the height that 4” projection is regulated for
27-80”
when do you need a 1 hour fire rated corridor
For non sprinklered spaces when the occupant load is more than 30 for most occupancies. this also includes the ceiling
or if you are in the institutional occupancy group regardless of occupancy load
what fire rating must a door have in a 1 hour rated wall assembly
20 min
when can you use glass in a fire rated corridor
if it is 3/4 hour fire-protection rated glass and the total area is less than 25% of the length of the wall it’s on
however if you use fire resistance rated glazing then there is no limit to how much you can use
when do egress doors need to swing out in the direction of travel
when they are serving any hazardous area or an occupant load of 50 or more
when is it mandatory to have panic hardware on a exit door
educational occupancy and assembly
when could you use a manual sliding door as a means of egress
in all occupancies other than H if the occupant load is less than 10
what is a stair
one or more risers
what is a stairway
one or more flights of stairs
what is the range for sizes of risers and treads
riser is between 4” and 7”H and the tread is no less than 11” deep except in residential or private stairs with OL less than 10, max riser can be 7.75” and min treat can be 10”
can you use a winding or spiral stair for an exit stair
only in group R-3 and R-1 if they meet certain conditions
how long (going down it’s in front of you, not the width) should a stair landing be
not less than the width of the stair bud doesn’t need to be longer than 48” long
why must an exit stairway be fully enclosed
because a vertical shaft is the most direct path for fire and smoke to travel
when are intermediate handrails required for a really wide stair
30” apart so no one is more than 30” away from a hand rail. Any stair wider than 5’ needs intermediate handrails
how many steps before you need a handrail
IBC says that even one step except for decks and patiors for R occupancies
how high should a hand rail be mounted
between 34 and 38” above the stair
how far does the handrail have to extend and at which end of the stair does it extend
12” min extension and at the top of the stairs
what is the minimum and maximum gripping diameter of a handrail & how far is it from the wall
min 1.25” and max 2” with a space 1.5” from the wall
what part of the design process does the permitting process begin
after the drawings and specifications have been completed
who is responsible for getting permits
the contractor
what kind of permit inspections happen in the interior design projects
framing, GWB, plumbing, mechanical , electrical & final inspection. GWB inspection is done before final tape and mud to verify that all are fire rated as required and constructed correctly
when would the fire alarm and sprinklers be inspected
in the final inspection
what do you have to do to get your certificate of occupancy
pass all the inspections and you get it once the final inspection is complete
what is an area of refuge
an area where people who can’t use stairs and wait for instructions or assistance in an emergency
in in most occupancies, what is the max distance for COMMON PATH of travel before two separate paths of two exits become available
for: sprinklered
unsprinkelered
sprinklered: 100 feet
unsprinkelered: 75 feet
how do you determine the max travel distance for a space
it’s the max travel distance from the most remote point to the nearest exit
based on occupancy and if the building is sprinklered
