Appeal 24150

Portland Fire & Rescue Alt. to Fire Access Roads / OSSC 1011.12.2

Portland Fire & Rescue- Fire & Life Safety Requirements for Fire Department Access, Alternate To Aerial Fire Apparatus Roads
Buildings complying with the following conditions will be exempt from the requirements of aerial fire apparatus access roads:

1. Building is equipped with an approved automatic sprinkler system,
2. There are no combustible concealed attic spaces,
3. All stairway exit enclosures shall have a fire-resistance rating of not less than 2 hours,
4. The roof is essentially flat (33-percent slope or less) and,
5. Approved access is provided to the roof from all stairways. In buildings without an occupied roof, access to the roof from the top story shall be permitted to be by an alternating tread device, a ship stair or ladder that provides a clear width of not less than 30 inches between handrails through a roof hatch or trap door not less than 30 inches (762 mm) wide and 8 feet (2438 mm) long (OSSC 1009).
6. Building requiring standpipes are equipped with at least one standpipe that terminates on the roof.

OSSC 1011.12 Stairway to roof
Exception: Other than where required by Section 1011.12.1, in buildings without an occupied roof, access to the roof from the top story shall be permitted to be by an alternating tread device, a ship’s ladder or a permanent ladder that is constructed of noncombustible material; is a minimum of 30 inches between handrails; has a rise and run of the stair or ladder of 12 inches maximum and 4 inches minimum, respectively; and has handrails provided on both sides of the stair or ladder.

1011.12.2 Roof Access
Exception: In buildings without an occupied roof, access to the roof shall be permitted to be a roof hatch or trap door not less than 30 inches wide and 8 feet long.

The intent of the appeal is to propose a 3' x 6' roof hatch for fire department access to the roof via a fixed, straight ladder.

The proposed apartment complex is made up of two separate buildings, each 3 stories above grade plane (the North building also has a basement level from which the single stairway is accessed) and composed of compact, 2-bedroom residential units, of which the North building has eight. The South building has been determined to comply with the requirements for aerial fire access, and is not included in this appeal.

The North building complies with the ‘alternate to aerial fire apparatus’ requirements (recently revised to include a full NFPA 13 sprinkler system- the original permit documents only proposed an NFPA 13R system), with the exception of a 3’ x 8’ roof access hatch. Instead, we propose access to the roof via a fixed, straight ladder to a 3’ x 6’ roof hatch. The ladder will comply with all relevant code requirements, including 30” clear width between posts and 6” toe clearance. The ladder will be equipped with a ladder cover to prevent unauthorized access, and the keys included in the apartment complex’s Knox box (or as otherwise required by the Fire Department).

The stairway is open air on one side, and enclosed with a 2-hour fire rated wall on the other 3 sides.

At the roof, the hatch will be equipped with a guard and gate assembly. The roof is unoccupied (houses a number of mechanical units), and minimally sloped.

The 8’ long roof hatch is sized with consideration for a sloping ship’s ladder, whereas the proposed straight ladder needs less clearance space behind ladder user, and provides adequate clearance for even the large amount of gear carried by firefighters accessing the roof. Furthermore, since the latch of the roof hatch is typically located in the center, a shorter hatch means less of a reach is required while on the ladder, allowing faster and safer access.

The exterior stair is conspicuous and easily accessible from a courtyard, meaning firefighters could quickly walk from the public way to the top landing of the stairs with no doors or other obstructions.

Per OSSC 1011.13, the roof hatch will be equipped with a guard at the roof, although the immediate area where a user emerges from the hatch is already greater than 10’ away from the edge of the roof.

Given the ease of access to the ladder and the configuration of the site, ladder, and hatch assembly, the proposed design meets or exceeds the level of life safety required by code.