Term
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Definition
| an area where persons unable to use stairways can remain temporarily to await instructions or assitance during emergency evacuation. |
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Term
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Definition
| an enclosed exit access component that defines and provides a path of egress travel to an exit. A corridor may or may not be protected depending on the particular requirements of the code. |
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Definition
| a court or yard (considered part of an exit discharge) that provides access to a public way for one or more required exits. In the IBC, this is not called an egress court. |
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Term
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Definition
| a fully enclosed portion of an exit that is only used as a means of egress and that provides for a protected path of egress either in a vertical or horizontal direction. In most instances, however, exit enclosures mean protected stairways. Depending on construction type and building type, an exit enclosure must have either a one-hour or two hour rating, and all openings must lead to an exit descharge or public way. |
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Term
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Definition
| a horizontal, fully enclosed portion of an exit that is only used as a means of egress. An exit passageway leads from an exit doorway to an exit discharge or public way. An common example of an exit passageway is an exit from the door at the ground level of an interior stairway that leads through the building to an outside door. |
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Term
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Definition
| an exit through an minimum two-hour rated wall that divides a building into two or more separate exit access areas to aford safety from fire and smoke. |
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Term
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Definition
| (new to the IBC) a change in elevation, consisting of one or more risers. |
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Term
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Definition
| one or more flights of stairs, either exterior or interior, with the necessary landings and platforms connecting them, to for a continuous and uninterupted passage from one level to another. |
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Term
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Definition
| the measurement of the distance between the most remote, occupiable point of an area or room to the entrance of the nearest exit that serves it. It is part of the exit access and is measured in a straight line along the path of exit travel. |
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Term
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Definition
| a continuous and unobstructed path of vertical and horizontal egress travel from any point in a building or structure to a public way. The means of egress consists of three parts: the exit access, the exit, and the exit discharge. These must lead to a public way which is a 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 10'. |
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Term
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Definition
| portion of the means of egress that leads to the entrance to an exit. |
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Term
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Definition
| the exit it the portion of the egress system that provides a protected path of egress between the exit access and the exit discharge. It is the portion of the egress system between the termination of an exit and a public way. |
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Term
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Definition
| are fully enclosed and protected from all other interior spaces by fire-resistance rated construction with protected openings. Exits can be as simple as an exterior door at ground level or may include exit enclosures for stairs, exit passageways, and horizontal exits. In the 2003 IBC, exits may also include exterior exit stairways and ramps. Exits must have a one or two hour rating, depending on the building height, construction type, and passageway length. |
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Term
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Definition
| number of people that a building code assumes will occupy a given building or portion of a building. Based on the occupancy classification. The first method of determining actual number of people the building or space is designed to accomodate becomes the occupant load. The second method the occupant load is determined by taking the area assigned to a particular use and dividing by an occupant load factor as given in the code. The third method, when an occupant load from an accessory space exits through a primary space, the egress facilities from the primary space occupant load must include their own occupant load plus the occupant load of the accessory space. |
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Term
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Definition
| is the amount of floor area presumbed to be occupied by one person. The gross floor area includes stairs, corridors, toilet rooms, mechanical rooms, closets, and interior partition thickness. Net floor area includes just the space actually used. |
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Term
| If there are mixed occupancies.. |
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Definition
| each area is calculated with its respective occupant load factor and then all loads are added together. |
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Term
| What is the occupant load for a restaurant dining room that is 2500 sf in area? |
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Definition
Dining rooms are listed under the use of "Assembly ares, unconcentrated use," with an occupant load factor of 15 square feet. Dividing 15 into 2500 give an occupant load of 167 persons.
And would require two exits because 167 persons exceeds 50 in the IBC table. |
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Term
| When the number of occupants of a space exceeds... |
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Definition
| the number given in the code, then at least two exits must be provided. The IBC requires two exits when the occupant load of a space exceeds the numbers given in IBC Table No. 1014.1 |
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Term
| Spaces with one means of Egress |
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Definition
A, B, E, F, M, U - 50 (maximum occupant load)
H-1, H-2, H-3 - 3
H-4, H-5, I-1, I-3, I-4, R - 10
S - 30 |
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Term
| Even if the occupant load of a space or a building is... |
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Definition
| less that that of the IBC table No. 1014.1 two exits are still required if the common path of egress travel exceeds limits given in the code. |
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Term
| The common path of egress travel |
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Definition
| is that 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. Even if two exits are not required based on occupant load, if the common path of travel exceeds 75' for all except H-1, H-2, H-3 occupancies, then two exits from a space are required. |
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Term
| When two exits are required... |
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Definition
| they must be placed a distance apart equal to not less than one-half the length of the maximum overall diagonal dimension of the building or area to be served, as measured in a straight line between the exits. The reason is the requirement is to position the exits far enough apart so taht a fire or other emergency would not block both exits. |
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Term
| If three exits are required... |
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Definition
| two exits must be placed a distance apart equal to not less than one half the length of the maximum overall diagonal dimension of the building or area to be served, measured in a straight line. |
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Term
| Maximum travel distances are based on.. |
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Definition
| occupancy of the building and whether or not the building is sprinklered. |
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Term
| Most codes allow a room to have one exit... |
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Definition
| through an adjoining or intervening roon if it provides a direct, obvious, and unobstructed means of travel to an exit ocrridor or other exit as long as the total maximum travel distances, described in the previous section are not exceeded. However, exiting is not permitted through kitchens, storerooms, rest rooms, closets, or spaces used for similar purposes. |
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Term
| Required minimum width of exits... |
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Definition
| is determined by multiplying the occupant load by the appropriate factor given in Table 1005.1 of IBC. The resulting number is the minimum total width in inches. |
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Term
| If two or more widths are required... |
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Definition
| the total width must be divided such that the loss of any one means of egress does not reduce the available capacity to less than 50% of the required capacity. |
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Term
| When two exits are required... |
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Definition
| corridors must be laid out so that it is possible to travel in two directions of an exit. |
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Term
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Definition
| Limited to a maximum of 20', but avoid if at all possible always. |
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Term
| Maximum width of a corridor... |
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Definition
| determined by taking the occupant load it serves and multiplying by 0.2, 0.15, or another factore given the code. The absolute minimum width for most occupancies is 44" if the corridor serves an occupant load of 50 or more. For occupant loads less than 50, the minimum width is 36". |
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Term
| The IBC Requires School corridors |
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Definition
| to be at least 72" when serving an occupant load of 100 or more. |
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Term
| The width of a corridor... |
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Definition
| must be unobstructed, but handrails and fully opened doors can protrude a maximum of 7" total. Other projections such as trim may extend into the width a maximum of 4" on each side. However, horizontal projections connot reduce the minimum clear width of accessible routes. |
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Term
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Definition
| must be built of one-hour fire-resistive construction when serving an occupant load of 10 or more in R-1 and I occupancies and when serving an occupant load of 30 or more in other occupancies. If the ceilig of the entire story is one-hour rated, then the rated corridor walls may terminate at the ceiling. Otherwise, the one hour rated corridors must extend through the ceiling to the rated floor or roof above. |
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Term
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Definition
| placed in one-hour corridors must have a fire rating of at least 20 minutes and include approved smoke and draft control seals around the door. The door must also be maintained self-closing (with a door closer) or be automatic closing by actuaction of a smoke detector. Both the door and frame must bear the label of an approved testing agency, such as UL. |
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Term
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Definition
| may be used in one hour rated corridor walls only if it is listed and labeled as a 3/4 hour fire protection rating and the total area does not exceed 25% of the area of the corridor wall of the room that it is separating fromt he corridor. |
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Term
| When a duct penetrates a rated corridor... |
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Definition
| it must be provided with a fire damper. |
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Term
| Corridor is required to be fire-resistance rated based on... |
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Definition
| occupancy, the occupant load served, and whether the building is sprinklered. |
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Term
| In a sprinklered building of occupancy A, B, E, F, I-1, I-3, M, S, and U |
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Definition
| corridors do not have to be fire-resistive rated. |
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Term
| Building code provisions apply to exit doors... |
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Definition
| serving an area with an occupant load of ten or more. |
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Term
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Definition
| must be pivoted or side-hinged and must swing in the direction of travel when serving any hazardous area or when serving an occupant load of 50 or more. In UBC, exit doors, must be a min. of 3' wide and 6'8" high. Max. width is 4'. Must be operable from the inside without the use of any special knowledge or effort. Certain occupancies such as educational and assembly, require panic hardware. |
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Term
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Definition
| must have fire rating if in fire-resistance rated partitions. The specific fire rating varies depending on the rating of the partition. |
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Term
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Definition
| is one that swells and chars when exposed to heat to form a barrier to smoke and fire. |
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Term
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Definition
| must have automatic closers, and all hardware must be tested and approved for use on fire exits. When closed, they must provide a tight seal against smoke and drafts. Glass in exit doors must be wired glass, and its total area is limited depending on the door's fire rating. |
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Term
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Definition
| serving an occupant load of 50 or more must be at least 44" wide or as wide as determined by multiplying the occupanct load by 0.3 or another factor as discussed previously. Those serving an occupant load of 49 or less must not be less than 36" wide. Handrails may project into the required width 4.5" on each side. |
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Term
| Risers of the stair cannot... |
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Definition
| be less than 4" or more than 7", and the tread must be no less than 11". Risers for barrier free stairs cannot exceed 7", treads must have an acceptable nosing design. |
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Term
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Definition
| the top of the handrail must be between 34" and 38" above the nosing of the treads and must extend not less than one tread depth beyond the top riser and not elss than 12" plus the depth of one tread beyond the bottom riser. The ends must be returned to the wall or floor or terminate in a newel post. The gripping portion cannot be less than 1 1/4" or more than 2" in cross-sectional dimension. There must be a space at least 1 1/2" wide between the wall and the handrail. |
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