§ 27-327 Ceilings.
AC § 27-327
(a)Ceilings that contribute to the required fire-resistance rating of a floor or roof assembly shall be continuous between exterior walls, vertical fire divisions, fire separations, corridor partitions or any other partitions having at least the same fire-resistance rating as the ceiling. All such fire-rated partitions shall be constructed as set forth in section 27-340 or subdivision (a) of section 27-341, as appropriate. The concealed space above such ceiling shall be firestopped into areas not exceeding three thousand square feet with materials listed in section 27-345 of this subchapter for the full height of the concealed space. Access to each such concealed space may be through one or more openings, not exceeding nine square feet and protected by self-closing opening protectives having the fire-protection rating required by table 5-3.
(1)Firestopping shall not be required where the structural members within the concealed space are individually protected with materials having the required fire-resistance rating, or where the ceiling is not an essential part of the fire-resistive assembly; nor shall firestopping be required where a concealed space is sprinklered in accordance with the construction requirements of subchapter seventeen of this chapter.
(b)Electrical and other openings in ceilings. Ceilings required to have a fire-resistance rating may be pierced to accommodate noncombustible electric outlet boxes or recessed lighting fixtures if the aggregate area of such openings does not exceed sixteen square inches in each ninety square feet of ceiling area and the electrical outlet boxes or recessed lighting fixtures are constructed of steel at least .022 inches thick and sealed tightly at the ceiling. Noncombustible pipes, ducts, and additional or larger electrical or other service facilities may pierce ceilings that are required to have a fire-resistance rating only when the type of ceiling to be used has been tested with such types of facilities installed in place and the proportionate area of openings for such facilities to be installed in the ceiling does not exceed the proportionate area of such openings in the assembly tested, and provided no opening is larger than that in the assembly tested. Protection for such openings shall be the same as provided in the test. Duct openings installed in accordance with the foregoing shall be protected by fire dampers complying with the requirements of subchapter thirteen of this chapter.
