Maintaining a fire resistance rating in compromised floor-ceiling material
What is a Fire-Rating?
Many people live in multi-family homes where individual living spaces are accessed via common corridors, stairways, and entry/exit doors. These common entry/exit passageways are constructed to provide approved levels of fire protection that enable occupants to safely exit the building in case of an emergency. DMF Lighting’s M Series, H Series, and DRD5S Series offer housing options with a two-hour fire rating, suitable for common entry/exit passageway applications when a fire rating is required. *Other fire barriers or methods of protection maybe utilized, such as a concrete structure or a sprinkler system.
Â
See the following product codes for more information:
M Series: M4NCRF, M4NCSF, M4LTRF, M4LORF, M4LTSF, M4LOSF
H Series: H3FR, F4NC
DRD5S Series: F4NC
What is the IBC?
The International Building Code® (IBC), developed by the International Code Council (ICC), is a model building code adopted and used as a base code standard throughout most of the USA. The IBC® is a complex and lengthy document with comprehensive requirements. Chapter 7 on Fire and Smoke Protection Features is key, and in particular Section 714 Penetrations: The provisions of this section shall govern the materials and methods of construction used to protect through penetrations and membrane penetrations of horizontal assemblies and fire-resistance-rated wall assemblies. Penetrations of ceiling membranes are covered in Section 714.5 where subsection 714.5.2 Membrane Penetrations states: Where floor/ceiling assemblies are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.
How can a recessed fixture be installed without reducing the fire rating of the floor/ceiling assembly? The traditional approach is shown above.
Although this is an effective method, it requires the ceiling space to have boxed-out cavities, using the same fire-rated membrane material, to mount the recessed fixtures in. This approach adds significant costs and requires extra space above the ceiling plane that may not always be available.
The M Series, H Series, & DRD5S family, fire-rated housings provide a new method of achieving the same result and is shown above.
DMF fire-rated junction box solutions reduce installation costs significantly because they eliminate the requirement to create boxed-out cavities at the time of construction by utilizing one of the exceptions provided by subsection 714.5.2: Ceiling membrane penetrations of maximum 2-hour horizontal assemblies by steel electrical boxes that do not exceed 16 square inches (10,323 mm²) in area, provided the aggregate area of such penetrations does not exceed 100 square inches (44,500 mm²) in any 100 square feet (9.29 m²) of ceiling area, and the annular space between the ceiling membrane and the box does not exceed 1/8 inch (3.2 mm).
DMF fire-rated junction box solutions reduce installation costs significantly because they eliminate the requirement to create boxed-out cavities at the time of construction by utilizing one of the exceptions provided by subsection 714.5.2: Ceiling membrane penetrations of maximum 2-hour horizontal assemblies by steel electrical boxes that do not exceed 16 square inches (10,323 mm²) in area, provided the aggregate area of such penetrations does not exceed 100 square inches (44,500 mm²) in any 100 square feet (9.29 m²) of ceiling area, and the annular space between the ceiling membrane and the box does not exceed 1/8 inch (3.2 mm).
UL 514A Standard for Safety - Metallic Outlet Boxes
More Than Just Fire-Rated
M Series, H Series, and DRD5S Families have been granted an unparalleled combination of other safety certifications, including Sound, Air-Tight, IC, and Wet Location ratings. You can be confident that DMF has a solution for you that is compliant in a wide range of installations.
Â
Â
Note: This Bulletin was originally published 07/10/2017 and has been updated to reflect the new product offerings.