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 C1397), the Application of Direct-Applied Finish Systems (Practice C1516), and the Application of Exterior Insulation Finish Systems Class PI (Practice C1535). 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 C220); non-asbestos fiber cement flat sheets for exterior applications such as claddings, facades, curtain walls, and soffits (Specification C1186); gypsum backing board, coreboard, and shaftliner (Specification C1396/ C1396M); water-resistant gypsum backing board (Specification C1396/C1396M); glass mat gypsum backing board (Specification C1178/C1178M); particle boards (Definitions D1554); and discrete non-asbestos fiber cement interior substrate sheets (Specification C1288).
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.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ASTM C1325-22 Referenced Document
ASTM C1154 Standard Terminology for Non-Asbestos Fiber-Reinforced Cement Products
ASTM C1178/C1178M Standard Specification for Glass Mat Water-Resistant Gypsum Backing Panel
ASTM C1185 Standard Test Methods for Sampling and Testing Non-Asbestos Fiber-Cement Flat Sheet, Roofing and Siding Shingles, and Clapboards
ASTM C1186 Standard Specification for Flat Non-Asbestos Fiber-Cement Sheets
ASTM C1288 Standard Specification for Discrete Non-Asbestos Fiber-Cement Interior Substrate Sheets
ASTM C1396/C1396M Standard Specification for Gypsum Board*, 2024-04-21 Update
ASTM C1397 Standard Practice for Application of Class PB Exterior Insulation and Finish Systems
ASTM C1516 Standard Practice for Application of Direct-Applied Exterior Finish Systems*, 2023-03-01 Update
ASTM C1535 Standard Practice for Application of Exterior Insulation and Finish Systems Class PI*, 2023-03-01 Update
ASTM C220 Standard Specification for Flat Asbestos-Cement Sheets
ASTM C473 Standard Test Methods for Physical Testing of Gypsum Panel Products
ASTM C666/C666M Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing*, 2024-04-21 Update
ASTM C947 Standard Test Method for Flexural Properties of Thin-Section Glass-Fiber-Reinforced Concrete (Using Simple Beam With Third-Point Loading)
ASTM D1037 Standard Test Methods for Evaluating Properties of Wood-Base Fiber and Particle Panel Materials
ASTM D1554 Standard Terminology Relating to Wood-Base Fiber and Particle Panel Materials*, 2023-08-04 Update
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 G21 Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi
ASTM G22 Standard Practice for Determining Resistance of Plastics to Bacteria (Withdrawn 2002)
ASTM C1325-22 history
2022ASTM C1325-22e1 Standard Specification for Fiber-Mat Reinforced Cementitious Backer Units
2022ASTM C1325-22 Standard Specification for Fiber-Mat Reinforced Cementitious Backer Units
2021ASTM C1325-21 Standard Specification for Fiber-Mat Reinforced Cementitious Backer Units
2019ASTM C1325-19 Standard Specification for Fiber-Mat Reinforced Cementitious Backer Units
2018ASTM C1325-18 Standard Specification for Fiber-Mat Reinforced Cementitious Backer Units
2017ASTM C1325-17a Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units
2017ASTM C1325-17 Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units
2014ASTM C1325-14 Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units
2008ASTM C1325-08b Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units
2008ASTM C1325-08a Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units
2008ASTM C1325-08 Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units
2004ASTM C1325-04 Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cement Substrate Sheets
1999ASTM C1325-99 Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cement Interior Substrate Sheets