Mike Dolt Enterprises
Mike Dolt Enterprises
User: Ccarlson32, Location: Wisconsin
Asked on: Thursday, January 23, 2025 at 8:11 am EST
Answered on: Thursday, March 6, 2025 at 7:41 am EST
Question: I have surfed the forums with multiple opinions as this pertains more to IBC than NEC.I have a fire rated floor/ceiling assembly that a customer would like recessed lights installed in.To maintain the fire rating of the ceiling, would using a canless wafer light rated for 2 hours comply? And if we are installing recessed lighting that does not reduce the fire resistance of the fire wall can have multiple lights installed and not follow the maximum 16 sq in within 100sq ft exception correct? (ie, we can have 2 or 20 of these fire rated lights and not have to worry about the size of the penetrations because we are replacing it with listed fixture will not reduce the fire resistance.)For the purposes of this thread, I was looking as using RAB FWAFER6. All FWAFER models have been tested to UL 263 and ASTM E119 standards for 2-hour fire resistance.The other option would be to install 'fire hats' above non rated can/canless lights, or drywall box out the penetrations if I understand the code correctly.ThanksSection 714.4.2 addresses membrane penetrations into fire rated walls.714.4.2 Membrane penetrations.Penetrations of membranes that are part of a horizontal assembly shall comply with Section 714.4.1.1 or 714.4.1.2. 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.Exceptions:1.Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.4.1 or to prevent the free passage of flame and the products of combustion. The aggregate area of the openings through the membrane shall not exceed 100 square inches (64 500 mm2) in any 100 square feet (9.3 m2) of ceiling area in assemblies tested without penetrations.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).3.Membrane penetrations by electrical boxes of any size or type, that have been listed as part of an opening protective material system for use in horizontal assemblies and are installed in accordance with the instructions included in the listing.4.Membrane penetrations by listed electrical boxes of any material, provided such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the ceiling membrane and the box shall not exceed 1/8 inch (3.2 mm) unless listed otherwise.5.The annular space created by the penetration of a fire sprinkler, provided it is covered by a metal escutcheon plate.6.Noncombustible items that are cast into concrete building elements and that do not penetrate both top and bottom surfaces of the element.7.The ceiling membrane of 1- and 2-hour fire-resistance-rated horizontal assemblies is permitted to be interrupted with the double wood top plate of a wall assembly that is sheathed with Type X gypsum wallboard, provided that all penetrating items through the double top plates are protected in accordance with Section 714.4.1.1 or 714.4.1.2 and the ceiling membrane is tight to the top plates.
You've done a good job of outlining the relevant code section and your potential solutions. Here's a breakdown of how to approach this, based on your provided information
Understanding the Goal
The key is to maintain the fire-resistance rating of the floor/ceiling assembly. This means ensuring that any penetration, like a recessed light, doesn't create a path for fire and smoke to spread.
Your Options & Analysis1. Fire-Rated Wafer Lights (e.g., RAB FWAFER6)
Compliance
This is the most direct solution. If the RAB FWAFER6 lights are listed as part of a fire-rated assembly that matches or exceeds the rating of your floor/ceiling assembly, and they are installed according to the listing instructions, you are generally compliant with IBC Section 714.4.
2.
Quantity
Because the lights are tested and listed to maintain the fire rating when installed correctly, the 16 sq in per 100 sq ft rule does not apply. You can install as many as needed, as long as they are installed according to the listing. The listing is what allows you to bypass the normal penetration rules. Make sure you have the documentation (listing) available for the inspector.
Important
The listing is CRITICAL. It needs to specifically state that the lights maintain the fire resistance rating of the entire floor/ceiling assembly, and provide detailed installation instructions. Verify that the listing covers the specific assembly type you have (e.g., concrete, wood joist with gypsum board, etc.).2.
Non-Rated Can/Canless Lights with Fire Hats or Drywall Boxing
Compliance
This is a viable alternative, but requires more work and careful detailing.
Fire Hats
These are essentially fire-rated enclosures that go above the recessed light. They're designed to contain a fire originating in the light fixture or block fire from spreading up into the ceiling cavity. They must be listed for use in the specific type of fire-rated floor/ceiling assembly.
Drywall Boxing
You can box out the area above the light with fire-rated drywall. This creates a fire-resistant barrier. This is more complex to do properly. All seams must be properly taped and mudded with fire-rated materials. You need to demonstrate that the box maintains the fire resistance rating.
Considerations for Hats/Boxing
Air Tightness
Ensure the fire hat or drywall box is sealed to prevent the passage of smoke and hot gases.
Clearance
Follow manufacturer's instructions for minimum clearances around the light fixture to prevent overheating, both for the fixture and the fire-rated enclosure.
Installation
Proper installation is vital. Gaps and unsealed joints will compromise the fire protection.
Key Considerations & Recommendations1. AHJ Approval
The most important step is to consult with your local Authority Having Jurisdiction (AHJ) (i.e., the building inspector or fire marshal). Present your plan and get their approval before starting the work. They have the final say and may have specific requirements or preferences.2.
Documentation
Gather all relevant documentation, including: The fire-resistance rating of the floor/ceiling assembly. The listing for the fire-rated lights (RAB FWAFER6) or the fire hats. Installation instructions for the chosen solution.3.
Installation Quality
Regardless of the method, ensure that the work is performed by a qualified electrician and is installed exactly according to the manufacturer's instructions and the listing requirements.4.
Alternative Solutions
Explore other recessed lighting options specifically designed for fire-rated assemblies. Some manufacturers offer integrated solutions that simplify the installation process.
In Summary Using fire-rated lights listed for use in your specific fire-rated floor/ceiling assembly is the simplest and generally most code-compliant solution. The RAB FWAFER6 appears promising if the listing supports your application. Non-rated lights with fire hats or drywall boxing can be used, but require more work and meticulous attention to detail.
Always get AHJ approval before* starting the work! They are the final authority on code compliance. Flag for review