This specification covers non-asbestos fiber-mat reinforced cementitious backer units manufactured to be dimensionally stable and suitable as either an unfinished substrate or as a substrate for decoration such as natural stone or tile on walls, floors, or decks in wet and dry areas. Flat sheets covered by this specification are divided into two types, according to their intended application: type A - sheets are intended for exterior applications as a substrate for other cladding materials, or as an unfinished substrate for decoration such as natural stone, tile, or coatings, and type B - Sheets are intended for covered exterior applications such as soffit areas, or for interior dry or wet area applications as a desired unfinished substrate or an unfinished substrate for decoration such as natural stone or tile, where substrate dimensional stability is required. These products are formed either with or without pressure and cured, either under natural or accelerated conditions, to meet the property requirements. Mechanical and physical properties shall be determined on an uncoated product wherever practical. The flexural strength, density value, and modulus of elasticity value shall be tested to meet the requirements prescribed.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers non-asbestos fiber-mat reinforced cementitious backer units manufactured to be dimensionally stable and suitable as either an unfinished substrate (see Note 1) or as a substrate for decoration such as natural stone or tile on walls, floors, or decks in wet and dry areas. It is also suitable to be used as a substrate in the Application of Class PB Exterior Insulation Finish Systems (Practice C 1397), the Application of Direct-Applied Finish Systems (Practice C 1516), and the Application of Exterior Insulation Finish Systems Class PI (Practice C 1535).

Note 1—When used as an unfinished substrate, consult the manufacturer's written installation literature for proper application details.

1.2 This specification is not applicable to asbestos-cement flat sheets (Specification C 220); non-asbestos fiber cement flat sheets for exterior applications such as claddings, facades, curtain walls, and soffits (Specification C 1186); gypsum backing board, coreboard, and shaftliner (Specification C 442); water-resistant gypsum backing board (Specification C 630); glass mat gypsum backing board (Specification C 1178); particle boards (Definitions D 1554); and discrete non-asbestos fiber cement interior substrate sheets (Specification C 1288).

1.3 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C220 Specification for Flat Asbestos-Cement Sheets

C442/C442M Specification for Gypsum Backing Board, Gypsum Coreboard, and Gypsum Shaftliner Board

C473 Test Methods for Physical Testing of Gypsum Panel Products

C630/C630M Specification for Water-Resistant Gypsum Backing Board

C666/C666M Test Method for Resistance of Concrete to Rapid Freezing and Thawing

C947 Test Method for Flexural Properties of Thin-Section Glass-Fiber-Reinforced Concrete (Using Simple Beam With Third-Point Loading)

C1154 Terminology for Non-Asbestos Fiber-Reinforced Cement Products

C1178/C1178M Specification for Coated Glass Mat Water-Resistant Gypsum Backing Panel

C1185 Test Methods for Sampling and Testing Non-Asbestos Fiber-Cement Flat Sheet, Roofing and Siding Shingles, and Clapboards

C1186 Specification for Flat Fiber-Cement Sheets

C1288 Specification for Discrete Non-Asbestos Fiber-Cement Interior Substrate Sheets

C1397 Practice for Application of Class PB Exterior Insulation and Finish Systems (EIFS) and EIFS with Drainage

C1516 Practice for Application of Direct-Applied Exterior Finish Systems

C1535 Practice for Application of Exterior Insulation and Finish Systems Class PI

D1037 Test Methods for Evaluating Properties of Wood-Base Fiber and Particle Panel Materials

D1554 Terminology Relating to Wood-Base Fiber and Particle Panel Materials

D2394 Test Methods for Simulated Service Testing of Wood and Wood-Base Finish Flooring

E84 Test Method for Surface Burning Characteristics of Building Materials

G21 Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi

G22 Practice for Determining Resistance of Plastics to Bacteria

ANSI Standards

Keywords

acceptance; air cured; appearance; density; edge straightness; finish; flexural strength; glass mat cement sheet; inspection; interior wet area application; length and width tolerance; mechanical properties; minimum equilibrium strength; minimum wet strength; moisture content; moisture movement; nominal length; nominal thickness; nominal width; non-asbestos fiber-mat; packaging; physical properties; pressure cured; sampling; shipping; squareness tolerance; storage; supplementary requirements; supplementary tests; surface burning characteristics; thickness requirements; thickness tolerance; third party certification; tolerance; type tests; warm water resistance; workmanship; Cement materials/applications--specifications; Fiber-mat reinforced cement substrate sheets; Glass mat cement sheet; Nonasbestos fiber-cement materials--specifications; Substrate sheets

ICS Code

Citing ASTM Standards

[Back to Top]