Specification

Backerboard for ceramic tile and exterior finish systems
– Lightest cement board in the industry
– Environmentally sustainable product—lower weight reduces embodied energy and embodied emissions
– Water-durable, mold-resistant substrate for high-moisture areas
– Suitable for use in interior or exterior applications
– Will not rot, warp, delaminate or disintegrate
– Easy to cut and fasten
– Noncombustible
Description Durock
®
cement board offers architects, builders and tile contractors a strong, water-durable tile base for tub
and shower areas. Also an ideal underlayment for tile on floors and countertops in new construction and
remodeling. Board is readily applied over wood or steel framing spaced 16" o.c. with corrosion-resistant wood
or steel screws or hot-dipped galvanized roofing nails. After joints are treated, ceramic wall or floor tile is applied
using latex fortified mortar or Type I organic adhesive.
Durock cement board is preferred by many applicators as a base for directly applied finishes, tile, stone and
thin-brick used in building exteriors.
Product Data
Sizes and Packaging
Standards Durock cement board exceeds ANSI standards for cementitious backer units (CBU). See ANSI A118.9 for test
methods and specifications for CBU and ANSI A108.11 for interior installation of CBU. Exceeds industry
standards as an exterior substrate for exterior finishes. Exceeds ASTM C1325 standards for non-asbestos
fiber-mat reinforced cementitious backer units.
Availability Durock cement board is distributed throughout the United States. Contact a United States Gypsum Company
sales office or sales person for additional information.
Composition and Materials Durock cement board is formed in a continuous process of aggregated portland cement slurry with polymer-
coated, glass-fiber mesh completely encompassing edges, back and front surfaces. The edges are formed
smooth. The ends are square cut.
Deilivery and Storage All materials should be delivered and stored in their original unopened package and stored in an enclosed
of Materials
shelter providing protection from damage and exposure to the elements. Even though the stability and durability
of
Durock cement board is unaffected by the elements, moisture and temperature variations may have an effect
on the bonding effectiveness of basecoats and adhesives. Store all
Durock cement board panels flat.
Environmental Conditions In cold weather and during Durock cement panel and tile installation, temperatures within the building shall be
maintained within the range of 40 to 100 °F. Adequate ventilation shall be provided to carry off excess moisture.
Interior Applications Wood framing shall approximate the moisture content it will reach in service by allowing the enclosed building to
stand as long as possible prior to the application of the cement board. Do not install board when the board is wet.
Exterior Applications Finishes, leveling/skim coats and basecoats should not be applied to Durock cement panel that is wet or frozen
or that contains frost. After application, and for at least 24 hours, finishes, leveling/skim coats and basecoats
should be effectively protected from rain and excessive moisture. In cold weather and during finish applications,
Durock cement panel, skim or basecoat, mortar, finish material and air temperature must be at least 40°F and
must remain at this temperature or higher for at least 24 hours after application. Hot and dry weather may
affect working time of leveling/skim or basecoat and finish materials. Under rapid drying conditions, dampening
or light fogging of board, leveling/skim or basecoat surface may be required to improve workability.
Submittal Sheet
Durock
®
Cement Board
Size (thickness x width x length)
1
Units (pcs)
2
1/2" x 32" x 5' 50
1/2" x 36" x 5' 50
1/2" x 32" x 8' 30
1/2" x 48" x 8' 30
5/8" x 36" x 5' 30
5/8" x 48" x 8' 24
1/4" x 36" x 5' 60
1. Other lengths available. Contact your USG Representative. 2. Shipped in packaging units as shown.