BCAB #1646 - Penetrations of Ceiling Membranes Providing Fire Resistance Rating, Division B Appendix D Subsection D-2.3.12.
June 4, 2008
Re: Penetrations of Ceiling Membranes Providing Fire Resistance Rating, Division B Appendix D Subsection D-2.3.12.
The subject is a four storey wood frame residential building where the fourth floor ceiling utilizes a gypsum board membrane to provide a 1 hour fire resistance rating in accordance with Appendix note D-2.3.12. Penetrations through the gypsum board membrane are made for electrical fixtures, ventilation grilles, access hatches and similar building services. The penetrations are protected by approved fire stop caulk with appropriate ratings or gypsum board protection above the membrane penetration.
Reason for Appeal
Appendix D-2.3.12. indicates where the fire resistance rating of a ceiling assembly is to be determined on the basis of membrane only and not the complete assembly, the rating may be determined from Table D-2.3.12. provided no openings are made in the ceiling membrane.
The appellant contends that building service openings protected with an equivalent membrane surrounding do not constitute an opening in the membrane as indicated in D-2.3.12. The appellant considers the intent of the term “openings” used in the Appendix note refers to unprotected openings.
Building Official's Position
The Building Official contends no openings of any type are permitted in the ceiling membrane where the fire resistance rating is soley based on the membrane. Further, there are no provisions outlined in the Code as indicated for tested floor assemblies, indicating how openings in a ceiling membrane can be protected so as to maintain the fire resistance rating of the ceiling membrane.
Appeal Board Decision #1646
Where the fire resistance rating is determined on the basis of the ceiling membrane only, it is the determination of the Board that Appendix D-2.3.12. does not permit openings located within the ceiling membrane. However the Board recognizes there are practical alternatives that may provide an equivalent level of protection.
George Humphrey, Chair