Chapter 20 Means of Egress Flashcards Preview

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Flashcards in Chapter 20 Means of Egress Deck (36):

**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


**Egress consists of three parts:

the exit access, the exit, and exit discharge, which must lead to a public way


**Public :

any street, alley, or similar parcel of land essentially unobstructed to the sky that is permanently appropriated to the public for public use, and has a clear width not less than 10’-0”


**Exit Access

-Portion of means of egress that leads to the entrance to an exit. Exit access areas may or may not be protected, depending on code, occupancy requirements, construction type. May include rooms, hallways, corridors, ramps, doorways

-Exit access does not provide protected path of travel; even fire-protection-rated corridors are considered exit access

-Exit access is part of building where travel distance is measured & regulated


**Exit discharge:

portion of egress system between termination of exit and public way.

-Typically include portions outside exterior walls, such as exit balconies, exterior exit stairways, exit courts

-Sometimes, lobby areas are allowed to serve as exit discharge, if exit door in lobby clearly visible, discharge level is sprinklered, entire area of discharge separated from areas below by same fire-resistance rating as for exit enclosure that opens onto it

-IBC considers exterior exit stairways, ramps to be exits, not exit discharge areas



portion of egress system that provides protected path of egress between exit access and exit discharge

-Fully enclosed & protected from other interior spaces by fire-resistance-rated construction with protected openings (doors/glass, etc.)

-May be as simple as exit door at ground level or may include exit enclosures for stairs, exit passageways, and horizontal exits

-May include exterior exit stairways & ramps

-Depending on building height, construction type, passageway length, exits must be 1- or 2-hour rated; travel distance is not an issue once exit is reached


**Math Question on test
"Occupant loads"

SQFT Area / Occupational load factor


**Gross floor area includes

stairs, corridors, toilet rooms, mechanical rooms, closets, partition thicknesses


**Net floor area includes

only space actually used


** Always round up, even it its .1 you still round up to next whole number



**IBC requires clear width of door opening to be used, NOT the door width; a 36” door actually provides about 33” of clear width when accounting for door thickness and stops when door is opened 90 degrees



**Exiting through intervening spaces

Building codes intend means of egress from a room or space should lead directly to a corridor, exit enclosure, exterior door, or some other type of exit element

Egress can pass through an adjoining room if room is accessory to area served, and is not an H occupancy; must have discernible path of egress travel to an exit

Egress CANNOT pass through kitchens, storerooms, closets, or spaces used for similar purposes

Exit access cannot pass through a room that can be locked to prevent egress
2006 IBC allows egress through stockrooms serving group M occupancy if conditions are met


Corridor width

Corridors must be sized using method of multiplying occupant load by appropriate factor, but cannot be less than 44”, there are some exceptions


Doors opening into path of egress travel can reduce required width up to ___ during course of swing, but when fully open, cannot project more than ___ into required width

½" during course of swing, but when fully open, cannot project more than 7” into required width


Horizontal projections (handrails, trim, fixtures, lights) can project horizontally from either side, max. ____,

4" but CANNOT reduce minimum clear width of accessible routes


Dead end: condition where bldg. occupant has only one choice of direction leading to an exit access doorway or exit Code allows dead ends in corridors if length less than _____



Size of doors
Minimum egress door opening width must be min. ____”

Clear opening width measured between door face & door stop when door open 90 degrees; in practice, this means ___” must be used for egress doors

Max. swinging egress door width is ___”, min. height ___”

Minimum egress door opening width must be min. 32”

Clear opening width measured between door face & door stop when door open 90 degrees; in practice, this means 36” must be used for egress doors

Max. swinging egress door width is 48”, min. height 80”


Doors without closers must have max. opening force of ____lbs, doors with closers___lbs

5lbs, 15lbs


Max. allowable force to set door in motion is ___lbs.

30 lbs


Panic hardware required for educational & assembly occupancies with occupant load of 50 or more



Fire doors must be self-closing or automatic closing;




means there is a closer or other device on door that returns door to closed position after use


Automatic-closing doors:

are those that are normally held open, but automatically close upon activation of smoke detector, fire-alarm system, or other approved device


Operating devices, including handles, pulls, latches, and locks must be installed____”min., ____” max. above finished floor, except for locks used only for security purposes

36" min and 48" max



one or more flights of stairs, with necessary landings and platforms connecting them, that form a continuous passage from one level to another


Exit stairways:

-Vertical shafts provide most readily available path for fire & smoke spreading upward from floor to floor, exit stairways must be completely enclosed

-in bldgs. four or more stories high, stairways must be enclosed with 2-hour rated walls; 1-hour rating used in lower buildings


Stairways serving an occupant load of 50 or more must be at least ___” wide, or as wide as determined by multiplying occupant load

44" wide


Stairways serving occupant loads less than 50 must not be less than ____” wide

36" Wide


Handrails may project ____” into required width



Risers: ___” min. ___” max.
Treads: min. ___”

Riser 4" min, 7" max
Tread: Min 11"


Nosing design required In residential occupancies, private stairways max. riser ____”

7 -3/4"


Landings must be provided at top & bottom of every stairway, min. dimension in direction of travel must not be less than width of stair, but need not be more than ____” if stair is straight run



Handrails must be provided on both sides of stair



Intermediate handrails required so all parts of stairway within 30” of handrail; stairs over 60” wide require intermediate handrails



Handrail tops must be ___”min, __” max. above tread nosings, must extend ___” beyond top riser, not less than one tread beyond bottom riser

Handrail tops must be 34”min, 38” max. above tread nosings, must extend 12” beyond top riser, not less than one tread beyond bottom riser


Handrail requirement exceptions (places where 2 handrails not required):

-Aisle stairs with center handrail

-Stairs within dwelling units, spiral stairways, aisle stairs serving seating on one side

-Decks, patios, walkways with single elevation change, where landing depth on each side is greater than required for landings