VA 06 16 63-2012 CEMENTITIOUS SHEATHING.pdf

1、05-01-12 06 16 63 - 1 SECTION 06 16 63 CEMENTITIOUS SHEATHING SPEC WRITER NOTES: 1. Use this section for exterior sheathing as a backup for ceramic tile, thin stone tile, thin brick, exterior insulation finish systems, and/ synthetic / stucco finishes, specified in Section 07 24 00, EXTERIOR INSULAT

2、ION AND FINISH SYSTEMS. 2. Coordinate with structural Section 05 40 00, COLD FORMED METAL FRAMING and show stud framing at 400 mm (16 inches), o.c maximum. Also specify lateral bracing when wind loads exceed 1.26 kg/sq.m. (30 pounds/sq.ft.), and as required for the project conditions. 3. Use water b

3、arrier applied to face of studs behind cement board units. 4. Detail walls, joints with other materials, base edge, expansion and control joint conditions for each system. Show locations of expansion and control joints on drawings. 5. Verify framing is designed for deflection not more than 1/360, st

4、uds alone. PART 1 - GENERAL 1.1 DESCRIPTION This section specifies cement board sheathing applied to frame wall construction, ready to receive subsequent finishes. 1.2 SUBMITTALS A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND SAMPLES. B. Samples: 1. Cement board pane

5、ls, 200 mm by 200 mm (8 inches by 8 inches), minimum size. 2. Fasteners, each type used. 3. Reinforcing tape for joints 300 mm (12 inches) long. 4. Water barrier backing, 300 mm (12 inches) square. C. Product Data: 1. Cement board sheathing. 2. Reinforcing tape. 3. Fasteners. 1.3 DELIVERY AND STORAG

6、E A. Deliver materials in containers with labels legible and intact. B. Store materials so as to prevent damage or contamination. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-05-01-12 06 16 63 - 2 SPEC WRITER NOTE: Update applicable publications t

7、o current issue at time of project preparation. 1.4 APPLICABLE PUBLICATIONS A. Publications listed below form a part of this specification to the extent referenced. Publications are referenced in the text by the basic designation only. B. American Society for Testing and Materials (ASTM): C954-10 St

8、eel Drill Screws for the Application of Gypsum Panel Products or Metal Plaster Bases to Steel Studs from 0.033 in. (0.84 mm) to 0.112 in. (2.84 mm) in Thickness. C1325-08 . Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units D226-09 Asphalt-Saturated Organic Felt Used in Roofing and Waterpro

9、ofing. D4586-07 . Asphalt Roof Cement, Asbestos-Free C. Federal Specifications (FS): UU-B-790 . Building Paper, Vegetable Fiber INT AMD 1 (Kraft, Waterproofed, Water Repellant and Fire Resistant) D. Gypsum Association: GA253 Application of Gypsum Sheathing. PART 2 - PRODUCTS 2.1 CEMENT BOARD SHEATHI

10、NG A. Conform to ASTM C1325, except as follows. B. Property Minimum Average Value 1. Flame Spread 5 2. Smoke Density 0 3. Thickness 13 mm (1/2 inch) 4. Minimum Width 800 mm (32 inches) SPEC WRITER NOTE: 1. Verify wind load at location. 2. When wind loads exceed 1.26 kg/m (30 pounds/sq.ft.) add these

11、 additional physical properties. /6. Flexural Strength wet and dry 6895 kpa (1000 psi) 7. Fastener Holding wet and dry 33 kpa (125 pounds) / 2.2 ACCESSORY MATERIALS A. Steel Drill Screws: ASTM C954. Modified for flat head. Bugle head not acceptable. B. Organic Felt: ASTM D226, Type II, 13.6 kg (30 l

12、b). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-05-01-12 06 16 63 - 3 C. Roof Cement: ASTM D4586 D. Joint Reinforcing Tape: 1. Minimum 100 mm (4-inches) wide open mesh alkali resistant. 2. Glass fiber mesh polymer coated as recommended by Cement

13、Board manufacturer. E. Water Barrier: FS UU-B-790. Type I (Barrier paper), Grade D (Water-vapor permeable). Other products meeting or exceeding the Federal specification for a water barrier with water vapor permeability are acceptable. PART 3 - EXECUTION 3.1 ENVIRONMENTAL REQUIREMENTS A. Do not inst

14、all units when temperature is below 4.5 degrees Celsius (40 degrees F). B. Do not install joint reinforcing tape when temperature is below 10 degrees Celsius (50 degrees F). SPEC WRITER NOTE: 1. Use water barrier behind cement board units. 2. Verify locations of control joints are shown; locate hori

15、zontal joints at each floor and vertical joints not over 4.87 m (16 feet) o.c. 3.2 INSTALLATION A. Remove wrapping and separate to allow air circulation for not less than seven days before installation. B. Installing Water Barrier over Framing Members: 1. Apply roof cement or tape to framing members

16、 sufficient to adhere and support water barrier. 2. Use either organic felt or water barrier. 3. Apply barrier shingle fashion with horizontal joints lapped not less than 50 mm (2 inches). Lap end joints over framing, not less than 100 mm (4 inches) cemented together with roof cement, stagger end jo

17、ints. 4. Do not leave over 300 mm (12-inch) wide strip exposed when work is stopped. 5. Coordinate with installation of flashing to lap water barrier over flashing. Install weeps every 600 mm (24 inches) or as detailed, directly above flashing. Provide for clear exit of water to exterior. 6. Repair

18、torn or cut barrier with barrier patch spanning framing space cemented to surface along top and side edges. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-05-01-12 06 16 63 - 4 C. Installing Cement Board Units: 1. Apply cement board sheathing immedi

19、ately over water barrier in accordance with GA-253, with rounded edges and rough side to exterior, except as specified otherwise. 2. Secure units to framing members with screws spaced not more than 200 mm (8 inches) on center and not closer than 13 mm (1/2-inch) from the edge of the unit. 3. Install

20、 screws so that the screw heads do not penetrate the surface of unit. 4. Install 13 mm (1/2-inch) wide horizontal control joints at floors and vertical control joints not over 4.87 m (16 feet) on center unless shown otherwise, maintain alignment. 5. Stop units at edges of building expansion joints.

21、6. Minimum bearing over framing members: 19 mm (3/4-inch.) SPEC WRITER NOTE: Joint and Surface treatment is not required for Exterior Insulation Finish System. D. Joint and Surface Treatment: Apply joint reinforcing tape over joints, exposed edges, and corners using adhesive recommended by manufactu

22、rer. E. Leave surface flush and ready to receive subsequent finishes. 3.3 PROTECTION AND REPAIR A. Protect board with temporary coverings against moisture until subsequent finish is applied. B. Patch and repair damaged surface prior to application of subsequent finish. 1. Fill cracks. 2. Replace loose, spalling or missing joint finish. 3. Replace broken or damaged boards. - - - E N D - - - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-