Installation
Cutting
Cut backerboard sheets, onsite, to the required size and shape by using the score-and-snap method. Use a tungsten-carbide tipped knife, 20-tooth tungstencarbide tipped powersaw or handsaw blade. Holes in sheets are made by drilling, using a tungsten-carbide tipped mansory bit, or by scoring with a carbide tipped hole punch and breaking out from the face side with a hammer. Smooth rough edges using a rasp or coarse sandpaper.
Walls
Fill corner gaps with silicone sealant compatible with fiber cement underlayments or other wall finished products. Place underlayments with a minimum ¼” (6.4 mm) clearance from the floor surfaces and other horizontal tile termination locations, such as above tub edges. Ensure this gap free of adhesive and grout. Fill gap with a flexible sealant.
Precautions
Comply with applicable building code requirements, including design, so that the deflection in a plane does not exceed the L/360 deflection criteria (L/720 for natural stone), including live and dead loads, for the specific joist spacing used.
Warranty
Cement Board ½” with G2 Technology underlayments are protected by a 20 year limited product warranty from the manufacturer. Copies are available wherever the product is sold and can be obtained by contacting the manufacturer.
Compound Materials
Cement Board underlayments are composed of Portland cement, ground sand, cellulose fibers and selected additives. Products are manufactured by the Hatschek process and cured by high pressure steam autoclaving.
Technical Data
Applicable Standards
ASTM International
ASTM C177 Standard Test Method for Steady-State Heat Flux Measure ments and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
ASTM C1185 Standard Test Methods for Sampling and Testing Non-Asbestos Fiber-Cement Flat Sheet, Roofing and Siding Shingles, and Clapboards
ASTM C1288 Standard Specification for Discrete Non-Asbestos Fiber- Cement Interior Substrate Sheets
ASTM D2394 Standard Methods for Simulated Service Testing of Wood and Wood-Base Finish Flooring
ASTM E84 Standard Test Method for Surface Burning Characteristics of Building Materials
ASTM E96 Standard Test Methods for Water Vapor Transmission of Materials
ASTM E136 Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 C
ASTM G21 Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi
American National Standards Institute (ANSI)
ANSI A108.11 Specifications for Interior Installations of Cementitious Backer Units
ANSI A118.1 Specifications for Dry-Set Portland Cement Mortar (included in ANSI A108.1)
ANSI A118.4 Specification for Latex Portland Cement Mortar
ANSI A118.9 Specifications for Cementitious Backer Units
ANSI A136.1 Organic Adhesives for Installation of Ceramic Tile
ANSI A137.1 Ceramic Tile
Environmental Considerations
Cement Board contains no glass fibers, gypsum, asbestos or formaldehyde.
Physical/Chemical Properties
Mold resistance
Cement Board ½” with G2 Technology meet requirements for fungus and bacteria growth of 1 when tested according to ASTM G21.
Weight
Cement Board ½” with G2 Technology – 2.6 psf (12.7 kg/m2) Flexural Strength (at equilibrium moisture content, ASTDM C1185)
Cement Board ½” with G2 Technology – 1700 psi (11.7 MPa)
Compressive Strenght (at equilibrium moisture content, ASTM D2394, steel plate substrate)
Cement Board ½” with G2 Technology – 6500 psi (45 MPa)
Thermal Values (ASTM C177)
Cement Board ½” with G2 Technology thermal conductivity – k-value 20.07 Btu/(ft2 x h x F) (34.7 W/(m x k))
Cement Board ½” with G2 Technology thermal resistance – R-value 0.5 ft2 x h x F/Btu(0.01 m2 x K/W)
Cement Board ½” with G2 Technology water vapor transmission – 2.84 perms