| SECTION 374B -ACCESS AND MEANS OF EGRESS FACILITIES AND EMERGENCY ESCAPES (PART ONE) | |
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374B.1 General. Access and means of egress facilities and emergency escapes shall be in conformance with CBC Chapter 3, Section 310.4 and as provided herein. |
INSERT JOHN E’S RULING REGARDING ACCESS. |
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374B.1.1 Accessibility 374B.1.1.1 General. Group R-9 Occupancies shall conform to accessibility requirements as for an R-1 Occupancy. |
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374B.1.2 Means of Egress Facilities Number of Exits shall be in conformance with CBC Chapter 10. Occupant Load Factor shall be pursuant to Section 368C.6 |
374B.1.2 Means of Egress Facilities The "occupant load factor" is the number of square feet which the code has determined will accommodate one person. 200 is the occupant load factor for UCRC spaces *, which means that it would require 2000 square feet to reach an occupant load of 10 (200 x 10 = 2000), which would trigger a requirement for a second means of egress out of that individual unit. The two exits are required to be a distance apart equal to at least half of the longest diagonal distance in the unit. It is also true that anytime there are more than 10 occupants above the first floor of a building, then that floor must have two means of egress. Usually this means stairs, often in fire-rated towers. |
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374B.1.2.1.1 Individual Units of Group R-9 Occupancies. In individual spaces of Group R-9 Occupancies a minimum of two exits shall be required from the individual space when the number of occupants is 10 or more. |
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374B.1.2.1.2 Existing Building Exits. One of the required exits for an existing Building serving an R-9 Occupancy may be a fire escape in conformance with Section 8-502 of the 1998 California Historical Building Code. |
374B.1.2.1.2 Existing Building Exits. This is an important relaxation of the code. Often fire escapes can be far easier to build than a fully complying stair tower, and if the building does not already have a second stairway this permission can be a "deal saver." |
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374B.1.3 Stairways. Stairways within an individual R-9 Occupancy unit shall comply as a minimum with the requirements for a residential or other private stair where the occupant load is less than 10 and as herein provided. Stairways serving two or more individual R-9 Occupancy units or an occupant load of 10 or more shall comply with CBC Chapter 10, Section 1003.3 and as herein provided. |
374B.1.3 Stairways. 374B.1.3.1 General. Staircases which are permitted in residences are also typically permitted within UCRC units, including 8" riser on 9" tread, winders and, when serving less than 400 square feet, spiral stairs. Additionally, ship’s stairs or ladders are permitted for access to mezzanines, sleeping mezzanines, and sleeping bunks with units. The use of ladders is a code relaxation–requiring a Notice of Limitation–for UCRC. |
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374B.1.3.2 Stairways in an Individual F-7 or R-7 UCRC Occupancy Unit. Stairways in an individual unit of R-9 Occupancy may alternatively comply with Section 368C.1.3.2.1 for a ship stair access, Section 368C.1.3.2.2 for a ladder access, or with Section 368C.1.3.2.3 for other means of access to a mezzanine, sleeping mezzanine, or built-in sleeping bunk. See Figures A-3B-1A & 1B; A-3B-2A & 2B; and A-3B-3. |
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374B.1.3.2.1 Ship Stair. A ship stair (ships ladder) which is a fixed ladder within the pitch range of 41.5 to 75 degrees from the horizontal, equipped with treads and stair rails may provide access to a private mezzanine, sleeping mezzanine, or built-in sleeping bunk within an individual unit of R-9 Occupancy provided a warning sign and illumination are installed at the ship stair to meet the requirements of the Building Official. There shall be 6-8" minimum headroom provided at the top of the ship stair except the headroom clearance for access to a built-in sleeping bunk may be 3'6" minimum. |
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374B.1.3.2.2 Ladder. A ladder may provide access to a sleeping mezzanine or a built-in sleeping bunk within an individual R-9 Occupancy if the rungs are 14" maximum on center, 20 inches minimum wide, with 7 inches minimum toe space (measured horizontally from the outside of the rung to the face of a wall or other surface) and a safety cage of 30 inches' minimum clear dimension is provided above 6'-8" height above the bottom of the ladder when the floor to floor height traversed by the ladder is greater than 9 feet and provided that a warning sign and illumination are installed at the ladder to meet the requirements of the building offcial. |
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374B.1.3.2.3 Other Means of Individual Unit Stairway Access. Other means of access to a sleeping mezzanine or built-in bunk bed by means of prefabricated access equipment (folding stairs, etc.) may be used if equivalent to the above, subject to building offcial approval and provided a warning sign and illumination are installed at the access. Alternative stairways pursuant to 1998 CBC Section 1003.3.3.7 may be utilized in an R-9 Occupancy. |
374B.1.3.2.3 Other Means of Individual Unit Stairway Access. This is a new provision of the code which opens the door to folding ladders such as might be used in residential attic access, at the discretion of the building department. |
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374B.1.3.2.4 Landing at a Sleeping Mezzanine. A stairway, ship stair (ships ladder), ladder or similar equipment providing access to a sleeping mezzanine in an individual R-9 Occupancy Unit shall terminate in a landing with a 3' minimum dimension in any direction. The landing shall have 6'-8" minimum headroom. There may be a single step up to the floor of the sleeping mezzanine of 12" maximum rise or otherwise steps complying with individual unit residential requirements shall be provided the same width of the landing in the direction up to the floor of the sleeping loft. See Figures A-3B-1A & 1B. |
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374B.1.3.2.5 Notice of Limitation. See Section X325B.3 for a "notice of limitation" required for any access based on Sections 368C.1.3.2.1, 368C.1.3.2.2, and 368C.1.3.2.3. |
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374B.1.3.3 Existing Stairways Serving Two or More Individual Units or Ten or More Occupants of an F-7 or R-7 Occupancy. Existing stairways serving two or more individual units of R-9 Occupancy may alternatively comply as provided herein. Fire escapes shall comply with Section 368C.1.2.1.2. |
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374B.1.3.3.1 Existing Width. Existing width of existing stairways shall not be less than 30" clear from wall to wall. Projections into this minimum width shall conform to current code. |
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374B.1.3.3.2 Rise and Run. Existing rise and run of existing stairways may conform to the code applicable at the time the existing stairway was constructed provided that the maximum rise does not exceed eight inches and the minimum tread is not less than nine inches. |
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374B.1.3.3.3 Headroom. Existing headroom of existing stairways shall not be less than 6 feet 6 inches. |
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374B.1.3.3.4 Landings. Existing landings of existing stairways may conform to the code applicable at the time the existing stairway was constructed but shall not be less than 30 inches in the direction of travel. |
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374B.1.3.3.5 Handrails. Existing handrails may conform to the code applicable at the time
the existing stairway was constructed. Handrails on both sides
of an existing stairway are not required if the existing stairway
was originally constructed with a handrail only on one side and
the stairway is less than 36 inches in width. |
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374B.1.3.3.6 Guardrails. Guardrails shall conform to CBC Section 509 but need not exceed 36 inches on existing stairways. |
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374B.1.3.3.6 Interior stairway construction. Existing interior stairway construction may remain if the stairway construction is structurally adequate and the stairway is fully sprinklered. |
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