ASTM WK45329

    Revision of C1325 - 08b Standard Specification for Non-Asbestos Fiber-Mat Reinforced Cementitious Backer Units

    (What is a Work Item?)

    Active Standard: C1325 - 14

    Developed by Subcommittee: C17.01 | Committee C17 | Contact Staff Manager


    1. Rationale

    Testing for, and reporting of, Density for these products is no longer relevant because manufacturers do not report the density of their products, only weight/sq. ft. Recent introduction of lightweight versions of CBUs by three of the CBU manufacturers demonstrates this is no longer a relevant attribute and should be removed. This is a needless requirement in this standard that creates extra work and expense in compliance for manufacturers without providing identifiable benefits.


    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;
    Citing ASTM Standards
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    Work Item Status

    Date Initiated:

    Technical Contact:
    Keith Poerschke

    Draft Under Development