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. M541

May 30, 2019

Unrestrained Assembly Rating — 1 Hr

Unrestrained Beam Rating — 1 Hr

This design was evaluated using a load design method other than the Limit States Design Method (e.g., Working Stress Design Method). For jurisdictions employing the Limit States Design Method, such as Canada, a load restriction factor shall be used — See Guide BXUV or BXUV7

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

    1. Flooring System — The flooring system shall consist of one of the following:

    System No. 1

    Subflooring — Min 23/32 in. thick wood structural panels, min grade "Underlayment" or "Single-Floor". Face grain of plywood or strength axis of panel to be perpendicular to trusses with joints staggered 4 ft. Plywood or panel mechanically fastened to trusses 12 in. OC in conjunction with construction adhesive.
    Vapor Barrier — (Optional) — Nom 0.030 in thick commercial asphalt saturated felt.
    Finish Flooring — Min 1 by 4 in. T & G lumber installed perpendicular to trusses, or min 15/32 in. thick wood structural panels, min grade "Underlayment" or "Single-Floor". Face grain of plywood or strength axis of panel to be perpendicular to trusses with joints staggered.

    System No. 2

    Subflooring — Min 23/32 in. thick wood structural panels, min grade "Underlayment" or "Single-Floor". Face grain of plywood or strength axis of panel to be perpendicular to trusses with joints staggered 4 ft. Plywood or panel mechanically fastened to trusses 12 in. OC in conjunction with construction adhesive.
    Vapor Barrier — (Optional) — Nom 0.010 in. thick commercial asphalt saturated felt.
    Finish Flooring - Floor Topping Mixture* — Min 3/4 in. thickness of floor topping mixture having a minimum compressive strength of 1800 psi. Refer to manufacturer's instructions accompanying the material for specific mix design.

    UNITED STATES GYPSUM COTypes LRK, HSLRK, CSD


    Floor Mat Materials* — (Optional) — Floor mat material loose laid over the subfloor. Refer to manufacturer's instructions regarding the minimum thickness of floor topping over each floor mat material.

    UNITED STATES GYPSUM COTypes SAM, LEVELROCK® Brand Sound Reduction Board, LEVELROCK® Brand Floor Underlayment SRM-25


    Alternate Floor Mat Material* — (Optional) — Floor mat material nominal 3/8 in. thick loose laid over the subfloor. Floor topping shall be a min 3/4 in. thick. Thickness increased to min 1 in. for used with LEVELROCK® Brand Floor Underlayment SRM-25.
    2. Structural Steel Members* — Pre-fabricated light gauge steel truss system consisting of cold-formed, galvanized steel chord and web sections. Trusses fabricated in various sizes, depths, and from various steel thickness. Trusses spaced max 48 in. OC.

    AEGIS METAL FRAMING, DIV OF MITEKUltra-Span, Pre-fabricated Light Gauge Steel Truss System


    3. Bridging — (Not Shown) — Location of lateral bracing for truss chord and web sections to be specified on truss engineering.
    4. Batts and Blankets* — (Optional) — Any thickness of mineral wool or glass fiber insulation fitted in the concealed space, draped over the resilient channels and gypsum board ceiling membrane. Any mineral wool or glass fiber insulation bearing the UL Classification Marking for Surface Burning Characteristics having a flame spread index of 25 or less and a smoke developed index of 50 or less may be used.

      See Batts and Blankets (BKNV) category in the Building Materials Directory for names of manufacturers.

    4A. Loose Fill Material* — (Optional) — As an alternate to Item 4, any thickness of loose fill material installed on top of gypsum board ceiling membrane. Any loose fill material bearing the UL Classification Marking for Surface Burning Characteristics having a flame spread index of 25 or less and a smoke developed index of 50 or less may be used.

      See Loose Fill Materials (BPHX) category in the Building Materials Directory for names of manufacturers.

    5. Furring Channels — Hat channels min 25 MSG galv steel, min 2-5/8 in. wide by min 7/8 in. deep, installed perpendicular to the trusses (Item 2), spaced a max of 16 in. OC when no insulation is used in the cavity and 12 in. OC when insulation is used in the cavity, except at gypsum board end joints. At end joints, two courses of channel positioned 6 in. OC, 3 in. on each side of gypsum board end joints. Channel splices overlapped 4 in. beneath steel trusses. Channels secured to each truss with No. 18 SWG steel wire double strand saddle ties.
    5A. Alternate Steel Framing Members* — (Not Shown) — As an alternate to Item 5, main runners, cross tees or channels, and wall angle or channels as listed below:
      a. Main Runners — Nom 10 or 12 ft long, 15/16 in. or 1-1/2 in. wide face, spaced 4 ft OC perpendicular to trusses. Main runners suspended a min of 2 in. beneath bottom chord of trusses with min 12 SWG galv steel hanger wires spaced 48 in. OC. Hanger wires to be located adjacent to main runner/cross tee intersections.
      b. Cross Tees or Channels — Cross tees, nom 4 ft long, 15/16 in or 1-1/2 in. wide face, or cross channels nom 4 ft long, 1-1/2 in. wide face, installed perpendicular to the main runners, spaced 16 in. OC when no insulation is used in the cavity and 12 in. OC when insulation is used in the cavity . Additional cross tees or cross channels used at 8 in. from each side of butted gypsum board end joints. The cross tees or cross channels may be riveted or screw attached to the wall angle or channel to facilitate the ceiling installation.
      c. Wall Angle or Channel — Used to support steel framing member ends and for screw attachment of the gypsum board. Min 0.016 in. thick painted or galvanized steel angle with 1 in. legs or min 0.016 in. thick painted or galvanized steel channel with a 1 by 1 1/2 by 1 in. profile, attached to walls at perimeter of ceiling with fasteners 16 in. OC.

      USG INTERIORS LLCTypes DGL, RX


    5B. Steel Framing Members* — (Optional, Not Shown) — As an alternate to Item 5.
      a. Furring Channels — Formed of No. 25 MSG galv steel, nominal 2-1/2 in. wide by 7/8 in. deep, spaced as indicated in Item 5, perpendicular to trusses. Channels secured to Cold Rolled Channels at every intersection with a 3/4 in. TEK screw through each furring channel leg. Ends of adjoining channels overlapped 12 in. and fastened together with two double strand No. 18 SWG galv steel wire ties, one at each end of overlap, or with two 3/4 in. TEK screws in each leg of the overlap section. Two furring channels positioned 3 in. OC, 1-1/2 in. on each side of gypsum board (Item 6) end joints, each extending a min of 6 in. beyond both side edges of the board.
      b. Cold Rolled Channels — 1-1/2 in. by 1/2 in., formed from No. 16 ga. galv steel, positioned vertically and parallel to trusses, friction-fitted into the channel caddy on the Steel Framing Members (Item 5Bd) and secured with two 3/4 in. TEK screws. Adjoining lengths of cold rolled channels lapped min. 12 in. and secured along bottom legs with four 3/4 in. TEK screws and wire-tied together with two double strand 18 SWG galv steel wire ties, one at each end of overlap.
      c. Blocking — Where truss design does not permit direct, full contact of the hanger bracket, a piece of nominal 3-5/8 in. x 20 ga. steel stud (blocking), min. 12 in. long to permit full contact of the hanger bracket, to be secured vertically to the side of the trusses at the top and bottom of the blocking at each Steel Framing Member (Item 5Bd) location with minimum 2-1/2 in. screws.
      d. Steel Framing Members* — Spaced 48 in. OC. max along truss, and secured to the truss on alternating trusses with two, No. 10-16 TEK screws through mounting holes on the hanger bracket.

      PAC INTERNATIONAL L L CType RSIC-SI-CRC EZ Clip


    5C. Steel Framing Members* — (Optional, Not Shown) — As an alternate to Item 5.
      a. Furring Channels — Formed of No. 25 MSG galv steel, nominal 2-1/2 in. wide by 7/8 in. deep, spaced as indicated in Item 5, perpendicular to trusses and friction fit into Steel Framing Members (Item 5Cc). Ends of adjoining channels overlapped 6 in. and tied together with double strand of No. 18 SWG galv steel wire near each end of overlap or with two TEK screws along each leg of the 6 in. overlap. Two furring channels positioned 6 in. OC, 3 in. on each side of gypsum board (Item 6) end joints. Butt joint channels held in place by strong back channels placed upside down, on top of, and running perpendicular to primary furring channels, extending 6 in. longer than length of gypsum side joint. Strong back channels spaced maximum 48 in. OC. Strong back channels secured to every intersection of primary furring channels with four 7/16 in. pan head screws, two along each of the legs at intersections. Butt joint channels run perpendicular to strong back channels and shall be minimum 6 in. longer than length of joint, secured to strong back channels with 7/16 in. pan head screws, two along each of the legs at intersection with strong back channels.
      b. Blocking — Where truss design does not permit direct, full contact of the hanger bracket, a piece of nominal 3-5/8 in. x 20 ga. steel stud (blocking), min. 12 in. long to permit full contact of the hanger bracket, to be secured vertically to the side of the trusses at the top and bottom of the blocking at each Steel Framing Member (Item 5Cc) location with minimum 2-1/2 in. screws.
      c. Steel Framing Members* — Used to attach furring channels (Item 5Ca) to trusses. Clips spaced 48 in. OC and secured along truss webs at each furring channel intersection with min. 3/4 in. long self-drilling No. 10-16 TEK screws through each of the provided hole locations. Furring channels are friction fitted into clips.

      PAC INTERNATIONAL L L CType RSIC-S1-1 Ultra


    6. Gypsum Board* — One layer of nom 5/8 in. thick by 48 in. wide boards, installed with long dimension parallel to trusses. Attached to the furring channels using 1 in. long Type S bugle-head screws spaced 8 in. OC along butted end-joints and 8 in. OC in the field.

    When Steel Framing Members (Item 5B) are used, nom 5/8 in. thick, 4 ft wide gypsum board, installed as described in Item 6. Adjacent butt joints staggered minimum 48 in. OC.

    When Steel Framing Members (Item 5C) are used, nom 5/8 in. thick, 4 ft wide gypsum board, installed as described in Item 6. Butt joints staggered minimum 24 in. OC.

    UNITED STATES GYPSUM COType C


    6A. Alternate Gypsum Board* — For use with Steel Framing Members* (Item 5A) - Nom 5/8 in. thick, 48 in. wide gypsum board installed with long dimension parallel to the main runners. Gypsum board fastened to each cross tee or channel with one screw located at the mid-span of the cross tee or channel, one screw located 1-1/2 in. from each wallboard side joint and 8 in. OC. Except at gypsum board end joints, gypsum board screws shall be located 1/2 in. from the joint. Gypsum board fastened to main runners with drywall screws 1/2 in. from side joints, midway between intersections with cross tees or channels and max. 8 in. OC. End joints of adjacent gypsum board sheets shall be staggered not less than 32 in. Gypsum board sheets screw attached to leg of wall angle with drywall screws spaced 8 in. OC.

    UNITED STATES GYPSUM COType C


    7. Gypsum Board Batten Strip* — Min. 3 in. wide gypsum board strips cut from the same gypsum panels described in Item 6. Gypsum board strips loosely-laid over each butt joint extending 3 in. on each side of the joint.
    8. Finishing System — (Not Shown) — Vinyl, dry or premixed joint compound, applied in two coats to joints and screw-heads. Nom 2 in. wide paper tape embedded in first layer of compound over all joints. As an alternate, nom 3/32 in. thick veneer plaster may be applied to the entire surface of gypsum board.
    9. Steel Beam — (Optional, Not Shown) — W8x35 min size, used to support structural steel members (Item 2) at ends.
    10. Ceiling Damper* — (Not Shown) - Max nom area shall be 224 sq in. with the length not to exceed 16 in. and the width not to exceed 14 in. Max height of damper shall be 14 in. Aggregate damper openings shall not exceed 89 sq in. per 100 sq ft of ceiling area. Damper installed in accordance with the manufacturers installation instructions provided with the damper. A steel grille (Item 12) shall be installed in accordance with installation instructions.

    POTTORFFModel CFD-521-ST


    11. Air Duct* — Any UL Class 0 or Class 1 flexible air duct installed in accordance with the instructions provided by the damper manufacturer.
    12. Grille — Steel grille, installed in accordance with the installation instructions provided with the ceiling damper.

    * 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 2019-05-30
BXUV.M541 M541 BXUV 100535881 DESIGN Active 20190530 20190530 730408054 730408054 100535881 100575661 114328003 114328003 730408054 730408054 585661003

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