ASTM_C_933_-_18.pdf

Designation:C93318Standard Specification forWelded Wire Lath1This standard is issued under the fixed designation C933;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This specification covers welded wire lath,flat orself-furring,with or without backing,designed for use as a baseto receive portland cement-based interior plaster and exteriorstucco.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2A641/A641M Specification for ZincCoated(Galvanized)Carbon Steel WireC11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsE2556/E2556M Specification for Vapor Permeable FlexibleSheet Water-Resistive Barriers Intended for MechanicalAttachment2.2 Federal Specifications:UU-B-790 BuildingPaper,VegetableFiber:(Kraft,Waterproofed,Water Repellent and Fire Resistant)33.Terminology3.1 Definitions of terms used in this standard shall be inaccordance with Terminology C11.4.Materials and Manufacture4.1 Welded wire lath shall be fabricated from not less than0.0625 in.(1.588 mm),cold-drawn,galvanized steel wire,conforming to Specification A641/A641M.4.1.1 Diameter tolerance for galvanized wire shall be inaccordance with Specification A641/A641M.4.1.2 The wire shall be zinc-coated(galvanized)in accor-dance with Specification A641/A641M.4.1.3 The factory-attached water-resistive barrier shall con-form to Federal Specification UU-B-790 or ASTM Specifica-tion E2556/E2556M.The water-resistive barrier shall be eitherabsorptive or water resistant.The water-resistive barrier shallhave a bursting strength of not less than that required tomaintain integrity under normal hand-or machine-applicationpressures.4.1.4 The factory-attached water-resistive barrier shall beattached to the lath to prevent accidental removal duringshipping,handling or installation.Attachment of the water-resistive barrier shall allow lapping of wire-to-wire and water-resistive barrier to water-resistive barrier of not less than onemesh at ends and edges and shall permit full embedment,in notless than14in.(6 mm)of plaster,of not less than one-half ofthe total length and width of the wire.4.1.5 The thickness of the embedment of the lath and plastershall be measured from the back plane of the back wire,exclusive of furring,to the water-resistive barrier or surface ofthe substrate.5.Dimensions and Permissible Variations5.1 Openings and Stiffening:5.1.1 Lath shall be welded at all intersections of wire toform openings not more than 2 by 2 in.(51 by 51 mm).5.1.2 Reinforced lath shall be permitted to be reinforcedcontinuously and parallel to the long dimension of the lath atintervals of not more than 6 in.(150 mm).Wires used for thispurpose shall range from 0.072 to 0.1205 in.(1.9 to 3.1 mm).Reduction of the size of the openings to less than 2 by 2 in.(51by 51 mm)shall also be permitted.5.1.3 Self-furring crimps on self-furring lath shall projectnot less than14in.(6 mm)from the plane of the back of thelath.5.2 ThicknessThe nominal thickness shall be18in.(3.2 mm),exclusive of self-furring crimps,with a permissiblevariation of 6132in.(0.8 mm).1This specification is under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and is the direct responsibilityof Subcommittee C11.02 on Specifications and Test Methods for Accessories andRelated Products.Current edition approved Oct.1,2018.Published October 2018.Originallyapproved in 1980.Last previous edition approved in 2014 as C933 14.DOI:10.1520/C0933-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk,Bldg.4 Section D,700Robbins Ave.,Philadelphia,PA 19111-5094,Attn:NPODS.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations