Rationale : Section 7.7 Edge Straightness Tolerance Since the inception of this standard there has never been a method established on how measure this. Section 7.1 indicates that Test Method C 473 should be used to determine this, but there is no test in C 473 for edge straightness. CBUs are manufactured on a conveyor type belt and with rails governing board width and edge straightness so edge straightness is virtually guaranteed by the process. This requirement should be removed.
Keywordsacceptance; 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;
Draft Under Development