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