ASTM_C_1787_-_14_2019.pdf

Designation:C178714(Reapproved 2019)Standard Specification forInstallation of Non Metallic Plaster Bases(Lath)Used withPortland Cement Based Plaster in Vertical WallApplications1This standard is issued under the fixed designation C1787;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.Scope1.1 This specification applies to the minimum installationrequirements for non metallic plaster bases used with portlandcement based plaster in vertical wall applications.1.2 Where a fire resistance rating is required for plasteredassemblies and constructions,details of construction shall be inaccordance with reports of fire tests of assemblies that havemet the requirements of the fire rating imposed.1.3 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues stated in each system may not be exact equivalents;therefore,each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.4 Details of construction for a specific assembly toachieve the required fire resistance,sound or acoustic ratingshall be obtained from reports of fire-resistance tests,engineer-ing evaluations,or listings from recognized fire testing,soundor acoustic laboratories.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.6 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:2C926 Specification for Application of Portland Cement-Based PlasterC954 Specification for Steel Drill Screws for theApplicationof Gypsum Panel Products or Metal Plaster Bases to SteelStuds from 0.033 in.(0.84 mm)to 0.112 in.(2.84 mm)inThicknessC1063 Specification for Installation of Lathing and Furringto Receive Interior and Exterior Portland Cement-BasedPlasterE631 Terminology of Building ConstructionsC1788 Specification for Non Metallic Plaster Bases(Lath)Used with Portland Cement Based Plaster in Vertical WallApplications3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods,See Terminology E631.3.2 Definitions of Terms Specific to This Standard:3.2.1 portland cement based plaster,nsee SpecificationC926.3.2.2 non metallic plaster base(lath),nmaterial used as abase for portland cement based plaster that is self furred andmeets or exceeds the requirements set forth in SpecificationC1788.3.2.3 framing member,nsee Specification C1063.4.Delivery and Storage of Materials4.1 All materials shall be delivered in original,undamagedcontainers.4.2 Store materials inside or under cover protected fromweather.1This test method is under the jurisdiction ofASTM Committee C11 on Gypsumand Related Building Materials and Systems and is the direct responsibility ofSubcommittee C11.03 on Specifications for the Application of Gypsum and OtherProducts in Assemblies.Current edition approved March 1,2019.Published March 2019.Originallyapproved in 2014.Last previous edition approved in 2014 as C1787 14.DOI:10.1520/C1787-14R19.2For 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.Copyright 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 issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 5.Coordination and Scheduling5.1 Coordinate and schedule installation of non metallicplaster base with related work of other sections.6.Materials6.1 Materials shall conform to the requirements of thereferenced specifications and standards and to the requirementsspecified herein.6.2 Portland Cement Based Plaster,in accordance withSpecification C926.6.3 Accessories,in accordance with Specification C1063.7.Application of Accessories7.1 In accordance with Specification C1063.8.Application of Non Metallic Plaster Bases8.1 WorkmanshipNon metallic plaster base shall be in-stalled so the finished plaster sur