FIRE-RESISTANCE DESIGN

Assembly Usage Disclaimer

BXUV - Fire Resistance Ratings - ANSI/UL 263 Certified for United States

BXUV7 - Fire Resistance Ratings - CAN/ULC-S101 Certified for Canada

See General Information for Fire-resistance Ratings - ANSI/UL 263 Certified for United States
Design Criteria and Allowable Variances

See General Information for Fire Resistance Ratings - CAN/ULC-S101 Certified for Canada
Design Criteria and Allowable Variances

Design No. W421

April 27, 2018

Nonbearing Wall Rating - 1 Hr

* Indicates such products shall bear the UL or cUL Certification Mark for jurisdictions employing the UL or cUL Certification (such as Canada), respectively.

    1. Floor and Ceiling Runners — Channel shaped runners, 3-3/4 in. wide (min), 1-1/4 in. legs, formed from min No. 18 MSG galv steel, attached to floor and ceiling with fasteners spaced 24 in. OC max.
    2. Steel Studs — Channel shaped, 3-5/8 in. wide (min), 1-1/2 in. legs, 7/16 in. folded back returns, formed from min No. 18 MSG galv steel spaced 16 in. OC max.
    3. Lateral Support Members — (Not Shown)—Where required for lateral support of studs, support may be provided by means of steel straps, channels or other similar means as specified in the design of a particular steel stud wall system.
    4. Gypsum Board* — Any 5/8 in. thick UL Classified Gypsum Board that is eligible for use in Design Nos. L501, G512 or U305. Nom. 5/8 in. thick, 4 ft wide. Gypsum board applied vertically with joints centered over studs. Fastened to the steel studs with 1-1/4 in. long Type S self-drilling, self-tapping steel screws spaced 8 in. OC along the edges and 12 in. OC in the field of the board.

    ACADIA DRYWALL SUPPLIES LTD (View Classification) — CKNX.R25370


    AMERICAN GYPSUM CO (View Classification) — CKNX.R14196


    BEIJING NEW BUILDING MATERIALS PUBLIC LTD CO (View Classification) — CKNX.R19374


    CERTAINTEED GYPSUM INC (View Classification) — CKNX.R3660


    CGC INC (View Classification) — CKNX.R19751


    GEORGIA-PACIFIC GYPSUM L L C (View Classification) — CKNX.R2717


    CONTINENTAL BUILDING PRODUCTS OPERATING CO, L L C (View Classification) — CKNX.R18482


    LOADMASTER SYSTEMS INC (View Classification) — CKNX.R11809


    NATIONAL GYPSUM CO (View Classification) — CKNX.R3501


    PABCO BUILDING PRODUCTS L L C, DBA PABCO GYPSUM (View Classification) — CKNX.R7094


    PANEL REY S A (View Classification) — CKNX.R21796


    SIAM GYPSUM INDUSTRY (SARABURI) CO LTD (View Classification) — CKNX.R19262


    GEORGIA-PACIFIC GYPSUM L L C (View Classification) — CKNX.R6937


    THAI GYPSUM PRODUCTS PCL (View Classification) — CKNX.R27517


    UNITED STATES GYPSUM CO (View Classification) — CKNX.R1319


    USG MEXICO S A DE C V (View Classification) — CKNX.R16089


    4A. Gypsum Board* — As an alternate to Item 4 — Nom. 5/8 in. thick gypsum panels applied vertically or horizontally. Horizontal edge joints and horizontal butt joints on opposite sides of studs need not be staggered or backed by steel framing. Gypsum panels fastened to framing with 1 in. long Type S steel screws 12 in. OC along vertical edges and in the field. Screws spaced a max 12 in. along the top and bottom edges of the wall for both vertical and horizontal applications.

    NATIONAL GYPSUM CO — Types eXP-C, FSK, FSK-C, FSK-G, FSL, FSW-C, FSW-G, FSW, FSW-3, FSW-5, FSW-6, FSMR-C


    4B. Gypsum Board* — (As an alternate to Item 4) — Installed as described in Item 4. 5/8 in. thick, 4 ft. wide, applied vertically only and fastened to the studs and plates with 1 in. long, Type S steel screws spaced, 12 in. OC.

    NATIONAL GYPSUM CO — SoundBreak XP Type X Gypsum Board


    5. Foamed Plastic* — As an alternate to Item 5 - Spray applied, foamed plastic insulation, at any thickness from partial fill to completely filling stud cavity. Spray-applied in the steel cavity against the Type Thermax rigid insulation or gypsum board on the exterior side of the wall when Item 11A is used.

    BASF CORP — Enertite® NM, Enertite® G, Spraytite® 178, Comfort Foam® 178, Spraytite® 81206, Walltite® 200, Walltite® US, Walltite® US-N, Spraytite® 158, Comfort Foam® 158, and Spraytite® 81205


    6. Foamed Plastic* — 1/2 in. to 3 in. thick, rigid polyisocyanurate insulation board attached to the studs with Type S steel screws in each corner of each piece of insulation board. Screws shall be min. 1/2 in. longer than thickness of insulation board or insulation board and gypsum board when Item 11A is used.

    DOW CHEMICAL CO — Type Thermax Sheathing, Thermax Light Duty Insulation, Thermax Heavy Duty Insulation, Thermax Metal Building Board, Thermax White Finish Insulation, Thermax ci Exterior Insulation, Thermax IH Insulation, Thermax Plus Liner Panel and Thermax Heavy Duty Plus (HDP)


    6A. Foamed Plastic* — (As an alternate to Item 6) — Expanded polystyrene insulation installed to a maximum nominal density of 2.0 lb/ft2.

    BASF CORP STYRENIC FOAMS DIV — — Type Neopor "F" Series


    7. Self-Adhered Flashing Tape or Sealant — Min 4 in. wide tape placed over joints of foamed plastic (Item 6) on exterior surface of wall or sealant placed within the joints of the foamed plastic (Item 6).
    8. Mortar Drop Protection — (Optional) - A 1 in. thick mesh consisting of entangled, extruded plastic threads on a continuous backing, placed by weepholes at bottom of air space behind brick veneer.
    9. Wall Anchor Ties — Wall anchors attached to steel studs with self-drilling, self-tapping steel screws, of sufficient length to penetrate steel studs a min. of 1/2 in. spaced max 24 in. OC.
    10. Vapor Retarder, Water Barrier or Water Resistive Barrier — (Optional) — As required.
    11. Brick Veneer — Any 4 in. wide brick. Min 1 in. airspace provided between veneer and Foamed Plastic (Item 6). Fastened over Foamed Plastic (Item 6) to steel studs with Wall Anchor Ties (Item 9).
    11A. Alternate Veneers — (Not Shown) - The following veneers may be used as an alternate to the Brick Veneer (Item 11) when Gypsum Board (Item 4) is also installed to the steel studs on the exterior side of the wall prior to the application of the Type Thermax Foamed Plastic (Item 6). Gypsum board installed to exterior side of the steel studs in the same manner as described in Item 4. The following exterior facings are to be installed in accordance with the manufacturer's installation instructions.
      a). Aluminum Siding — 0.019 in. min thick painted aluminum meeting AAMA 1402. Fastened over Foamed Plastic (Item 6) to steel studs.
      b). Steel Siding — (Not Shown) — 0.017 in. min thick (No. 17 GSG gauge) painted steel. Fastened over Foamed Plastic (Item 6) to steel studs.
      c). Vinyl Siding — (Not Shown) — 0.035 in. min thick vinyl, UL Classified exterior plastic siding (Molded Plastic). Fastened over Foamed Plastic (Item 6) to steel studs.
      d). Wood Siding — (Not Shown) — 0.313 in. min thick lumber, plywood or OSB wood based siding. Fastened over Foamed Plastic (Item 6) to steel studs. As an option, the Wood Siding may be placed between the Foamed Plastic and Fiber-Cement Siding (Item f), Stucco (Item i) or One-Coat Stucco (Item j).
      e). Hard board Siding — (Not Shown) — 0.250 in. min thick hard board exterior siding. Fastened over Foamed Plastic (Item 6) to steel studs.
      f). Fiber-Cement Siding — (Not Shown) — 0.250 in. min thick fiber-cement based siding. Fastened over Foamed Plastic (Item 6) to steel studs.
      g). Stone — (Not Shown) — 2.0 in. min (natural stone) or 1.5 min (cast artificial) thick stone. Fastened over Foamed Plastic (Item 6) to steel studs.
      h). Concrete Masonry Veneer — (Not Shown) — 2.0 in. min thick concrete masonry units. Fastened over Foamed Plastic (Item 6) to steel studs with metal ties.
      i). Stucco — (Not Shown) — Portland cement type, 0.750 in. min thickness. Metal lath or mesh base fastened over Foamed Plastic (Item 6) to steel studs.
      j). One-Coat Stucco — (Not Shown) — 0.375 in. min thickness. Wire fabric lath fastened over Foamed Plastic (Item 6) to steel studs.
      k). Exterior Insulation and Finish System (EIFS) — (Not Shown) — Base coat with reinforcing mesh applied over Foamed Plastic (Item 6) followed by finish coat.
      l). Metal Panel — (Not Shown) — 0.039 in. min. thick metal panel or metal-composite-metal (MCM) panel. Fastened over Foamed Plastic (Item 6) to steel studs.
    12. Joint Tape and Compound — Vinyl or casein, dry or premixed joint compound applied in two coats to joints and screw heads of gypsum board. Paper tape, 2 in. wide, embedded in first layer of compound over all joints.

    * Indicates such products shall bear the UL or cUL Certification Mark for jurisdictions employing the UL or cUL Certification (such as Canada), respectively.

Last Updated on 2018-04-27
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