Mike Dolt Enterprises
Mike Dolt Enterprises
User: Ccarlson32, Location: Wisconsin
Asked on: Wednesday, January 22, 2025 at 3:37 pm EST
Answered on: Thursday, March 6, 2025 at 7:38 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.
Okay, let's break down the IBC requirements and how they apply to your recessed lighting situation, focusing on the RAB FWAFER6 example you provided.
Understanding the Code (IBC 714.4.2)
The core principle here is to maintain the fire-resistance rating of the floor/ceiling assembly. IBC 714.4.2 deals with penetrations of the membrane (the ceiling) of that assembly. The primary concern is preventing the spread of fire and smoke through these penetrations.
Analyzing Your Options and Code Compliance
Using Fire-Rated Canless Wafer Lights (e.g., RAB FWAFER6)
Compliance
This is generally the BEST and MOST DIRECT way to comply. If the RAB FWAFER6 (and its installation method) is listed to UL 263 and ASTM E119 standards for a 2-hour fire resistance rating that matches or exceeds the floor/ceiling assembly rating, and you install it according to the listing, you are essentially replacing the fire resistance you're removing when you make the hole.
Key
Pay very close attention to the listing and installation instructions. The listing will specify the types of assemblies it's approved for, the maximum opening size, and any required sealing or gasketing.
Advantage
Simpler and often cleaner installation than other methods. Less concern about the 100 sq. in. per 100 sq. ft. limitations.
Multiple Fixtures
You are correct. Assuming the fire-rated fixture is properly installed and listed for the assembly, you do not need to adhere to the 16 sq in per fixture limit, or 100 sq in per 100 sq ft. The listed fixture replaces the removed fire resistance.
RAB FWAFER6 Specifics
You need to thoroughly review the actual listing document for the RAB FWAFER6. Don't just rely on marketing materials. The listing document will tell you exactly what conditions it's approved for. Look for the UL 263 listing.2.
Fire Hats or Drywall Boxing
Compliance
These are possible methods, but more complex and potentially problematic.
Fire Hats
These are essentially fire-rated enclosures placed above the recessed light. They prevent fire from passing through the opening. The fire hats would have to be listed for the floor/ceiling assembly in question.
Drywall Boxing
Similar to fire hats, but you're building the enclosure out of fire-rated drywall. The construction method has to be fire-rated and meet the requirements of the assembly.
Challenges
Space
Fire hats and drywall boxes require significant space above the ceiling. This might not be available in all situations.
Complexity
Installation is more involved. Drywall boxing requires precise construction and sealing.
Listing Requirements
You'd still need to demonstrate that the fire hat or drywall box, when installed with the recessed light, maintains the fire resistance of the assembly. It may be necessary to test this system.
Meeting Exception 1 if not listed
If you are not using a tested and listed system, you will need to comply with exception 1 where 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.
In Summary
Fire-rated fixtures (RAB FWAFER6) installed per their listing are your best option. They directly address the code requirement to maintain the fire resistance of the assembly. Careful attention to the listing is crucial. Fire hats and drywall boxing are possible, but more complex and require careful planning and documentation to demonstrate code compliance. If you are not using a listed system that does not reduce the fire resistance of the assembly, you must comply with exception 1 of 714.4.2, in that the aggregate area of all 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. Always consult with your local building official to confirm their specific interpretation and acceptance of the proposed solution. They have the final say.
Recommendation
Obtain the listing document for the RAB FWAFER6 and thoroughly review it. Make sure it's listed for use in the specific type of floor/ceiling assembly you have.2. Discuss the installation plan with the building official before starting work. This can save you time and money in the long run.3. If the RAB FWAFER6 doesn't meet the requirements of your particular assembly, research other listed fire-rated fixtures.By following these steps, you can ensure that your recessed lighting installation complies with the IBC and maintains the required fire safety of the building. Flag for review