09 26 00 - GYPSUM AND CEMENTITIOUS BOARD ASSEMBLIES Specs.pdf

FBGS IDG Updated: 8 April 2022

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DIVISION 09 - FINISHES

SECTION - 09 26 00

GYPSUM AND CEMENTITIOUS BOARD ASSEMBLIES

PART 1 GENERAL

1.1 SD-07 CERTIFICATES: Submit certificates that gypsum board types, gypsum backing board types, cementitious backer units, and joint treating materials do not contain asbestos and are GREENGUARD Certified Gold.

1.2 SUPERINTENDENT QUALIFICATIONS: Engage a gypsum board installer and finisher with not less than 5 consecutive years of successful experience in gypsum board installation and finishing similar in size and type to the door requirements of the project

1.3 DELIVERY, STORAGE, AND HANDLING: Deliver materials in the original packages, containers, or bundles with each bearing the brand name, applicable standard designation, and name of manufacturer, or supplier. Keep materials dry by storing inside a sheltered building. Where necessary to store gypsum board and cementitious backer units outside, store off the ground, properly supported on a level platform, and protected from direct exposure to rain, snow, sunlight, and other extreme weather conditions. Provide adequate ventilation to prevent condensation. Store per manufacturer's recommendations for allowable temperature and humidity range. Gypsum wallboard shall not be stored with materials which have high emissions of volatile organic compounds (VOCs) or other contaminants. Do not store panels near materials that may off gas or emit harmful fumes, such as kerosene heaters, fresh paint, or adhesives.

1.4 SUPERINTENDENT QUALIFICATIONS: Engage a gypsum board installer and finisher with not less than 5 consecutive years of successful experience in gypsum board installation and finishing similar in size and type to the door requirements of the project

1.5 PROJECT/SITE CONDITIONS: Maintain a uniform temperature of not less than 50 degrees F in the structure for at least 48 hours prior to, during, and following the application of gypsum board, cementitious backer units, and joint treatment materials, or the bonding of adhesives. Protect gypsum board and cementitious backer unit products from direct exposure to rain, snow, sunlight, and other extreme weather conditions.

Provide temporary ventilation.

1.6 SCHEDULING: The gypsum wallboard shall be taped, spackled, and primed before the installation of the highly-emitting materials, including VOCs, formaldehyde, particulates, or other air-borne compounds.

PART 2 PRODUCTS

2.1 GYPSUM BOARD GENERAL: Provide 48-inches wide 96-inches long panel’s 0.625-inch thick with long edges tapered. The surface paper must be moisture/mold/mildew resistant on the front, back, and long edges. The mold and moisture resistance must be 0

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when tested in accordance with ASTM G 21 with a score of 10 when tested in accordance with ASTM D 3273. The water absorption rate must be Less than 5% when tested in accordance with ASTM C 473.

a. Type X Mold and Mold and Moisture Resistant Gypsum Board: The core must be of Moisture Resistant and Fire-Resistant Gypsum.

b. Type X Impact and Mold and Moisture Resistant Gypsum Board: The core must be of Moisture Resistant and Fire-Resistant Gypsum. The panel must be reinforced gypsum panel with imbedded fiber mesh or Lexan backing tested in accordance with the following tests. Hard body impact test must attain a Level 2 performance in accordance with ASTM C1629/C1629M. The panel must pass

ASTM E695 and ASTM D5420.

2.2 CEMENTITIOUS BOARD GENERAL: Provide in accordance with the Tile Council of

America (TCA) Handbook, ASTM C 1325 and ANSI A 118.9. Provide 36 inches wide

60 inches long panel’s 0.5-inch thick with long edges tapered. The core must be cementitious and water durable. The surface must have a fiberglass mesh on front and back. The mold and moisture resistance must be 0 (zero) when tested in accordance with

ASTM G 21, with a score of 10 (ten) when tested in accordance with ASTM D 3273. The water absorption rate must be Less than 5% when tested in accordance with ASTM C

473.

2.3 JOINT TAPE:

a. Gypsum Board: Provide Cross-laminated, tapered edge, reinforced paper for gypsum board

b. Cementitious Board: Provide non-alkaline mesh tape for cementitious board.

c. Fluid Applied Fluid Applied Water Proofing Reinforcing Fabric: Provide manufactures standard reinforcing fabric to pretreat cracks, corners, coves and floor and wall intersections, pipes, penetrations

2.4 TRIM: Provide pre-punched knurled aluminum-zin coated steel or paper-faced tape-on beads with galvanized metal corner and edge. Use thickness per gypsum assembly.

a. CORNERBEAD: Provide cornerbead with 2 inch flanges.

b. L-BEAD: Provide where gypsum assemblies intersect or abut dissimilar surfaces in existing construction with 3/4 inch to 1 inch Flange.

c. U-BEAD OR J BEAD TRIM: Provide where gypsum assemblies intersect or abut dissimilar surfaces with 7/16 inch to 1 inch exposed flange and 1/2 inch to 1 inch concealed edge.

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2.5 IMPACT CORNER GUARDS: Provide flush mounted high impact corner guards for all exterior corners of gypsum assemblies. Corner guard salient characteristics: cover-extruded high impact vinyl, nominal 0.1 inch thickness minimum colored throughout, retainer-mill finish aluminum 0.070 inch thickness minimum, and closure caps-injection molded thermoplastic. Dimensions: width-3 inch, length-84 inches.

2.6 EXPANSION AND CONTRACTION JOINTS: Install expansion and contraction joints in ceilings and walls in accordance with ASTM C840, System XIII or GA 216. Fill control joints between studs in fire-rated construction with fire-safing insulation to match the fire-rating of construction.

2.7 SEALANTS: Seal openings around pipes, fixtures, and other items projecting through gypsum board and cementitious backer units with Fire and Smoke Barrier Sealant. Apply material with exposed surface flush with gypsum board or cementitious backer units.

2.8 ADHESIVES: Adhesive must meet the requirements of LEED low emitting materials.

2.9 GYPSUM BOARD JOINT COMPOUND:

a. Gypsum Board: Provide in accordance with the ASTM C475/C475M.

Compounds must contain inert fillers and natural binders, including lime compound. Pre-mixed compounds shall be free of antifreeze, vinyl adhesives, preservatives, biocides, and other slow releasing compounds.

b. TAPING COMPOUND: Specifically formulated and manufactured for use in embedding tape at gypsum board joints and compatible with tape, substrate, and fasteners.

c. ALL PURPOSE COMPOUND: Specifically formulated and manufactured to serve as both a taping and a finishing compound, and compatible with tape, substrate and fasteners.

d. SETTING OR HARDENING TYPE COMPOUND: Specifically formulated and manufactured for use with fiber glass mesh tape.

2.10 CEMENTITIOUS BOARD JOINT COMPOUND: Provide unmodified white thinset mortar to fill all seams and fasteners.

2.11 FASTENERS: Secure Gypsum and Cementitious Board with screws, nails shall not be used.

a. Gypsum Board: Provide 6 x 1.625-inch bugle head drill tip screws for maximum

2 layers of 0.625-inch gypsum board, for thicker assemblies conform to United

States Gypsum (USG) Handbook for fastener gauge and length.

b. Cementitious Board: 9 x 1.625-inch serrated head screws

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2.12 FLUID APPLIED WATERPROOFING: Provide fluid applied premium Waterproofing and Crack-Isolation Membrane, that exceeds ANSI A118.10 (Waterproofing Membranes for Thin-Set Ceramic Tile) and ANSI 118.12 standard (Crack-Isolation Membranes for

Thin-Set Ceramic Tile); has a ASTM: C627 (Robinson) service rating of Extra Heavy, and meets the requirements of ASTM: E96, Procedure E (Desiccant Method) at 100°F of

< 0.5 p.

PART 3 EXECUTION

3.1 FRAMING AND FURRING: Verify that framing and furring are, free of deleterious substances, securely attached and of sizes and spacing to provide a suitable substrate to receive gypsum board and cementitious backer units. Verify that all blocking, headers, and supports are in place to support plumbing fixtures and to receive soap dishes, grab bars, towel racks, and similar items. Do not proceed with work until framing and furring are acceptable for application of gypsum board and cementitious backer units.

3.2 APPLICATION OF GYPSUM BOARD: Apply gypsum board to framing and furring members in accordance with ASTM C840 or GA 216 and the requirements specified.

Panels must be applied, first to ceilings framing members then to walls framing members.

Apply gypsum board with separate panels in moderate contact; do not force in place.

Stagger end joints of adjoining panels not less than one stud spacing. Neatly fit abutting end and edge joints. Use gypsum board of maximum practical length; select panel sizes to minimize waste. Follow manufacturers written instructions on how to cut, drill, and attach board; make neat, close, and tight joints around openings.

3.3 PANEL LAYOUT: Lay out panels to minimize waste. Treat edges of cutouts for plumbing pipes, screw heads, and joints as recommended by the gypsum board manufacturer. Attach boards 8 inches on center to edges, and 12 inches on center to intermediate studs. Abut ends of boards over centers of studs, and stagger end joints of adjacent board’s not less than one stud spacing. Attach boards at perimeter and within field of board to each stud. Panel joints must be located so that no end joint will align with edges of opening unless, control joints are installed at the juncture to the deck or the top of the wall. End joints must be staggered, and joints on opposite sides of a partition must not occur on the same stud.

3.4 FASTENING PANELS: Fastening must proceed from center portion of the board toward the edges and ends. Fasteners must be set with the heads slightly below the surface of the board in a dimple formed by the power screwdriver. Care must be taken to avoid breaking the face of the panels. Use adhesive only where screw type attachment is not possible. Use adhesive at each support forming a continuous gasket for all exterior walls.

3.5 EXPANSION, CONTRACTION AND CONTROL JOINTS: Install as specified in

United States Gypsum Construction Handbook Do not bridge building expansion joints.

Size control joint to accommodate calculated movement. Provide joints to accommodate

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movement at changes in geometry and at 24 feet on center. Install ceiling control joints in areas exceeding 900 Square feet. Space control joints not more than 30 feet on center.

Install control joints where ceiling framing or furring changes direction.

3.6 FINISHING OF GYPSUM BOARD: Tape, finish and Install trim accessories in accordance with ASTM C840, GA 214, GA 216 and the United States Gypsum

Construction Handbook. Provide Level 4 Finish typical, except provide Level 5 Finish where light is projected parallel along the surface.

3.7 APPLICATION OF CEMENTITIOUS BOARD: Apply cementitious board to framing and furring members securely. Apply cementitious board with separate panels in moderate contact; do not force in place. Stagger end joints of adjoining panels not less than one stud spacing. Neatly fit abutting end and edge joints. Use cementitious board of maximum practical length; select panel sizes to minimize waste. Follow manufacturers written instructions on how to cut, drill, and attach board; make neat, close, and tight joints around openings.

3.8 FINISHING OF CEMENTITIOUS BOARD: Fill all seams and fasteners with unmodified white thinset mortar. Thinset shall not be applied such that joints and fasteners telegraph in the finished work.

a. Showers: Provide Premium Waterproofing and Crack-Isolation Membrane with joints reinforced with Reinforcing Fabric to 20 mils dry for the field and pretreated cracks, corners, coves and floor and wall intersections, pipes, penetrations, with 2 coats to 20 mils dry. The water proofing system shall be system shall be a minimum 20 mils dry in the field and minimum 40 mils dry in pretreated locations.

b. Bath and Kitchens: Provide Premium Waterproofing and Crack-Isolation

Membrane

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