There is a UL Classification document for each of our UNIQUE Fire Stop Systems applications. Click on any link below to view the UL ratings. All have been tested to UL 1479 standards. The Hourly Fire Resistance Ratings listed are F Ratings. Some of our systems also have T and L Ratings. Scroll to the bottom of the page to see the definitions for each UL rating type.
Split Sleeve Firestop Systems
- Split Sleeve-Concrete 2 Hr UL W-J-3110
- Split Sleeve-Concrete 4 Hr UL W-J-3112
- Split Sleeve-Drywall 1& 2 Hr UL W-L-3232
- Split Sleeve-Drywall 3 & 4 Hr UL W-L-3234
- Split Sleeve-Vertical Concrete 2 & 3 Hr UL F-A-3019
- W-L-3273 Sleeve for 3 or 4 hr walls / 3 hr T rating
- Leakage ratings for our Systems: UL W-L-3122d
Other Classified UL Systems data for Split Sleeve Firestop:
- 3M Split Sleeve System
- Hilti W-L-0023 (empty 2 or 4 inch sleeve systems)
- Hilti W-L-3122 (cable bundle)
- Hilti W-L-3273 (3 or 4 hour walls)
- Hilti W-L-3282 (1 or 2 hour walls)
- Nelson Split Sleeve System Engineered System # ES2090B
Smooth Firestop/Penetrator Systems *
- Smooth Firestop-Concrete 2 Hr UL W-J-3109
- Smooth Firestop-Drywall 1 & 2 Hr UL W-L-3231
- Leakage ratings for our Systems: UL W-L-3122d; W-L-2197 (innerduc or plastic pipe)
* These systems are limited to 2 hour rated horizontal installations.
Other UL Classified Systems data for Smooth Firestop:
- 3M Smooth Penetrator System
- Hilti W-L-0023 (empty 2 or 4 inch sleeve systems)
- Hilti W-L-2197 (innerduct)
- Hilti W-L-3122 (cable bundle)
- Hilti W-L-3282 (1 or 2 hour walls)
- Nelson Smooth Penetrator System Engineered System # ES2090A
Threaded Firestop/Penetrator Systems
- Threaded Firestop-Concrete 2 Hr UL W-J-3111
- Threaded Firestop-Concrete 4 Hr UL W-J-3112
- Threaded Firestop-Drywall 1 & 2 Hr UL W-L-3233
- Threaded Firestop-Drywall 3 & 4 Hr UL W-L-3234
- Threaded Firestop-Vertical Concrete 2 & 3 Hr UL F-A-3019
- W-L-3273 Sleeve for 3 or 4 hr walls / 3 hr T rating
- Leakage ratings for our Systems: UL W-L-3122d
Other Classified UL Systems data for Threaded Firestop:
- 3M Threaded Firestop/Penetrator System
- Hilti W-L-0023 (empty 2 or 4 inch sleeve systems)
- Hilti W-L-3122 (cable bundle)
- Nelson Threaded Penetrator System Engineered System # ES2090C
T – Rating
- W-L-3273 Sleeve for 3 or 4 hr walls / 3 hr T rating
- W-L-3220 Membrane Firestop 1/4 hr T rating
- W-L-2197 (innerduc or plastic pipe)
Bulkhead Plates
Membrane Firestop/Penetrator Systems
Smooth Endcaps
Threaded Endcaps
- Threaded Endcaps-Concrete 2, 3, & 4 Hr UL W-J-0013
- Threaded Endcaps-Drywall 1, 2, 3, & 4 Hr UL W-L-0022
Retrofit Metal Electrical Box
Fill Kit (Putty) MSDS
Unique “L” Ratings
- Leakage ratings for our Systems: UL W-L-3122d
Unique Fire Stop Products UL Ratings with Other Brands of Putty
3M UL Systems
Hilti UL Systems
- Hilti W-L-0023 (empty 2 or 4 inch sleeve systems)
- Hilti W-L-2197 (innerduct)
- Hilti W-L-3122 (cable bundle)
- Hilti W-L-3220 (Membrane Penetrator)
- Hilti W-L-3273 (3 or 4 hour walls)
- Hilti W-L-3282 (1 or 2 hour walls)
Nelson UL Systems
- Nelson Split Sleeve System Engineered System # ES2090B
- Nelson Smooth Penetrator System Engineered System # ES2090A
- Nelson Threaded Penetrator System Engineered System # ES2090C
How to Calculate the Percent Fill of Your Fire Stop Sleeve
Our systems come with enough Unique Putty for a minimum 25% and maximum of 48% cable load.

Packing (Eliminated for 1 or 2 hr. Systems)
Listings with 3-M, Hilti, Rectorseal and Nelsons all require a minimum of 1 inch of mineral wool batt insulation, packed tightly, into both ends of the sleeve and recessed for the amount of sealant to be used. The wool batt acts as a backing for the intumescent sealant that is used to seal both ends of the sleeve. Mineral wool batt insulation is a common fireproof material used to insulate hot water heaters, fireplace inserts, and heating ducts. The best source for this packing material are the local commercial insulators in your area. Most distributors stock it as well. Note that some old-timers may call it rock wool. Our vertical and 4 hr. Systems do require this packing.
Intumescent Fill Material (putty)
All of our sleeve systems require the use of an intumescent caulk or putty to seal both ends of the sleeve. This material expands in the presence of heat / flame, suppressing the spread of a fire through the sleeve system penetration. The way a sleeve is packed and sealed are directly proportional to the amount of time a system will suppress a fire. For example, a 1 inch thickness of intumescent putty may be sufficient for a 1 or 2 hour rated penetration but a 3 or 4 hour application might require a 2 (or more) inch thickness in the ends of a sleeve system. Several fill material manufacturers have developed, tested, or engineered through penetration systems combining our sleeves and their fill material. All of our systems have our UNIQUE Intumescent Putty included with the sleeve.
Fire Stopping by the Numbers for Cable Installers:
- You must know the hourly rating of the barrier. (5/8″ fire rated gypsum is rated for 1/2 hr. per sheet / Cement Cinder Blocks are rated at 2 hrs.)
- Select the UL Listing to match or exceed the barrier. Pay attention to cable loads and fill procedure in the Listing.
- Go to the Cable Load Chart link for the product you selected. Select the proper size Sleeve, based on the % cable fill load permitted in the U.L. Listing.
- Seek pre-approval from the Authority Having Jurisdiction (Inspector). Remember, it is approved, if the Inspector says it is!
- When installing the System, be sure not to exceed the listing limitations. Read the listing.
- After installation, fill out the label and take a picture to document the System for future reference.
If you follow the steps listed above, you will guarantee AHJ acceptance.
Understanding the UL Ratings Designations
The first letter of the listing designation identifies the type of penetrated fire-rated structure:
C for both floor and wall penetrations
F for floor penetrations only
W for wall penetrations only
The second letter of the designation identifies the construction type:
A for concrete floors less than or equal to 5 inches thick
B for concrete floors greater than 5 inches thick
C for framed floors
D for deck construction
J for concrete or masonry walls less than or equal to 8 inches thick
K for concrete or masonry walls greater than 8 inches thick
L for framed walls
M for bulkheads
Flame: The “F” rating is expressed in hours. This number indicates the specific length of time a barrier can withstand fire before being consumed or before permitting the passage of flame through an opening. Temperature: The “T” rating is expressed in hours and indicates the length of time the temperature on the side of the penetration without fire does not exceed 325 F above the ambient temperature. This ensures the temperature on the side of the wall away from the flame does not reach the flash point of any materials on that side of the wall. Smoke: The “L” rating is the amount of air (smoke) that can leak through a penetration, measured in cubic feet per minute. The test is administered at ambient temperature and at 400 F to determine the actual performance of fire-stopping materials at different temperatures. Water: The “W” rating, established in 2004, indicates the fire-stopping material has passed the UL test for water tightness. The Class One requirements for water tightness include subjecting the material to a 3-foot water column for 72 hours, followed by a fire and hose stream test, conducted in accordance with ANSI/UL 1479. A Class Two listing requires the material to be resistant to a 20-foot water pressure head. Finally, a Class Three listing requires the material to be resistant to 57.54-foot water pressure head. According to one of its spokesmen, UL developed the new “W” rating to prevent water damage and mold-friendly moisture associated with through penetrations.