THROUGH-PENETRATION FIRESTOP SYSTEMS - W-L-1001 - Seismic Anchorage and Bracing Notes

Oct 23, 2026

THROUGH-PENETRATION FIRESTOP SYSTEMS W-L-1001 documents construction requirements and performance dependencies for fire-rated wall and penetration assemblies. It specifies wall framing options, gypsum board thickness and layer configurations, permissible annular opening limits, and approved penetrant materials including steel, cast iron, conduits, and copper piping. It also defines required caulk or sealant bead details and clarifies that firestop system hourly F and T ratings depend on the installed wall assembly rating and penetrant type/size. Seismic anchorage and bracing notes reference the 2018 IBC, establish bracing independence for in-line equipment, prohibit friction-type anchors, and require positively attached hangers and engineer review.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages116

Reading Time4 h 52 min

AccessFree to download

Section A-A

Wall Assembly Requirements (1, 2, 3 or 4 Hr)

Through-Penetrant Construction and Materials

Caulk/Sealant and Firestop Rating Dependencies

Seismic Anchorage and Bracing Notes

General Requirements

Attachment Prohibitions and References

| SYSTEM NO. W-L-1001
JUNE 15, 2005
F RATINGS - 1, 2, 3 AND 4 HR (SEE ITEMS 2 AND 3) T RATINGS - 0, 1, 2, 3, AND 4 HR (SEE ITEM 3) L RATING AT AMBIENT - LESS THAN 1 CFM/SQ FT L RATING AT 400 F - LESS THAN 1 CFM/SQ FT

SECTION A-A
1. WALL ASSEMBLY-THE 1, 2, 3 OR 4 HR FIRE-RATED GYPSUM WALLBOARD/STUD WALL ASSEMBLY SHALL BE CONSTRUCTED OF THE MATERIALS AND IN THE MANNER DESCRIBED IN THE INDIVIDUAL U300 OR U400 SERIES WALL OR PARTITION DESIGNS IN THE UL FIRE RESISTANCE DIRECTORY AND SHALL INCLUDE THE FOLLOWING CONSTRUCTION FEATURES:
A. STUDS-WALL FRAMING MAY CONSIST OF EITHER WOOD STUDS (MAX 2 H FIRE RATED ASSEMBLIES) OR STEEL CHANNEL STUDS. WOOD STUDS TO CONSIST OF NOM 2 BY 4 IN. (51 BY 102 MM) LUMBER SPACED 16 IN. (406 MM) OC WITH NOM 2 BY 4 IN. (51 BY
102 MM) LUMBER END PLATES AND CROSS BRACES. STEEL STUDS TO BE MIN 3-5/8 IN.(92 MM) WIDE BY 1-3/8 IN. (35 MM) DEEP CHANNELS SPACED MAX 24 IN. (610 MM) OC.
B. GYPSUM BOARD* -NOM OR†IN. (13 OR 16 MM) THICK, 4 FT. (122 H 1/20CM) WIDE WITH SQUARE OR TAPERED EDGES. THE GYPSUM WALLBOARD TYPE, THICKNESS, NUMBER OF LAYERS, FASTENER TYPE AND SHEET ORIENTATION SHALL BE AS SPECIFIED IN THE INDIVIDUAL U300 OR U400 SERIES DESIGN IN THE UL FIRE RESISTANCE DIRECTORY. MAX DIAM OF OPENING IS 26 IN. (660 MM) .
2. THROUGH-PENETRANT-ONE METALLIC PIPE, CONDUIT OR TUBING INSTALLED EITHER CONCENTRICALLY OR ECCENTRICALLY WITHIN THE FIRESTOP SYSTEM. THE ANNULAR SPACE BETWEEN PIPE, CONDUIT OR TUBING AND PERIPHERY OF OPENING SHALL BE MIN OF 0 IN / (0 MM) . (POINT CONTACT) TO MAX 2 IN. (51 MM) PIPE, CONDUIT OR TUBING TO BE RIGIDLY SUPPORTED ON BOTH SIDES OF WALL ASSEMBLY. THE FOLLOWING TYPES AND SIZES OF METALLIC PIPES, CONDUITS OR TUBING MAY BE USED:
A. STEEL PIPE-NOM 24 IN. (610 MM) DIAM (OR SMALLER) SCHEDULE 10 (OR HEAVIER) STEEL PIPE.
B. IRON PIPE-NOM 24 IN. (610 MM) DIAM (OR SMALLER) SERVICE WEIGHT (OR HEAVIER) CAST IRON SOIL PIPE, NOM 12 IN (305 MM) DIAM (OR SMALLER) OR CLASS 50 (OR HEAVIER) DUCTILE IRON PRESSURE PIPE.
C. CONDUIT-NOM 6 IN. (152 MM) DIAM (OR SMALLER) STEEL CONDUIT OR NOM 4 IN (102 MM) DIAM (OR SMALLER) STEEL ELECTRICAL METALLIC TUBING
D. COPPER TUBING-NOM 6 IN. (152 MM) DIAM (OR SMALLER) TYPE L (OR HEAVIER) COPPER TUBING
E. COPPER PIPE-NOM 6 IN. (152 MM) DIAM (OR SMALLER) REGULAR (OR HEAVIER) COPPER PIPE.
F. THROUGH PENETRATING PRODUCT* -FLEXIBLE METAL PIPING THE FOLLOWING TYPES OF STEEL FLEXIBLE METAL GAS PIPING MAY BE USED:
1. NOM 2 IN. (51 MM) DIAM (OR SMALLER) STEEL FLEXIBLE METAL GAS PIPING.
PLASTIC COVERING ON PIPING MAY OR MAY NOT BE REMOVED ON BOTH SIDES OF FLOOR OR WALL ASSEMBLY. OMEGA FLEX INC
2. NOM 1 IN. (25 MM) DIAM (OR SMALLER) STEEL FLEXIBLE METAL GAS PIPING. PLASTIC COVERING ON PIPING MAY OR MAY NOT BE REMOVED ON BOTH SIDES OFFLOOR OR WALL ASSEMBLY. GASTITE, DIV OF TITEFLEX
3. NOM 1 IN. (25 MM) DIAM (OR SMALLER) STEEL FLEXIBLE METAL GAS PIPING. PLASTIC COVERING ON PIPING MAY OR MAY NOT BE REMOVED ON BOTH SIDES OF FLOOR OR WALL ASSEMBLY. WARD MFG INC
3. FILL, VOID OR CAVITY MATERIAL* -CAULK OR SEALANT-MIN 5/8 . , 1-1/4,1-7/8 AND 2-1/2 IN.(16, 32, 48 AND 64 MM) THICKNESS OF CAULK FOR 1, 2, 3 AND 4 HR RATED ASSEMBLIES, RESPECTIVELY, APPLIED WITHIN ANNULUS, FLUSH ¼ IN. (6 MM) DIAM BEAD OF CAULK APPLIED TO GYPSUM BOARD/PENETRANT INTERFACE AT POINT CONTACT LOCATION ON BOTH SIDES OFWALL. THE HOURLY F RATING OF THE FIRESTOP SYSTEM IS DEPENDENT UPON THE HOURLY FIRE RATING OF THE WALL ASSEMBLY IN WHICH IT IS INSTALLED, AS SHOWN IN THE FOLLOWING TABLE. THE HOURLY T RATING OF THE FIRESTOP SYSTEM IS DEPENDENT UPON THE TYPE OR SIZE OF THE PIPE OR CONDUIT AND THE HOURLY FIRE RATING OF THE WALL ASSEMBLY IN WHICH IT IS INSTALLED, AS TABULATED BELOW:
Maximum Pipe or Conduit Diameter Inches F
Rating
Hours F
Rating
Hours 1 (25) 1 or 2 0+, 1 or 2 1 (25) 3 or 4 3 or 4 4 (102) 1 or 2 0 6 (152) 3 or 4 0 12 (305) 1 or 2 0
+WHEN COPPER PIPE IS USED, T RATING IS 0 H.3M COMPANY-CP 25WB+ OR FB-3000 WT.
*BEARING THE UL CL

FAQs

What wall and board construction is required for a 1, 2, 3 or 4 hour fire-rated assembly under W-L-1001?

The wall assembly must follow the materials and construction features described in the applicable U300 or U400 series wall or partition designs in the UL Fire Resistance Directory, including specified stud framing and gypsum board type, thickness, layers, fastener type, and orientation.

Which through-penetrant types are allowed in the firestop system?

Allowed penetrants include metallic pipes, conduits, and tubing (steel pipe, cast iron soil pipe, steel conduit, copper tubing, copper pipe) and certain flexible metal gas piping products, with defined nominal diameters and supporting requirements on both sides of the wall assembly.

How do the firestop system hourly F and T ratings relate to the wall assembly and penetrant?

The hourly F rating depends on the hourly fire rating of the wall assembly where installed. The hourly T rating depends on the type or size of the pipe or conduit and the hourly fire rating of the wall assembly, as tabulated in the referenced table.

Oct 23, 2026

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