ASTM_C_1858_-_17.pdf

Designation:C185817Standard Practice forDesign,Construction,and Material Requirements for DirectHung Suspended T-bar Type Ceiling Systems Intended toReceive Gypsum Panel Products in Areas Subject toEarthquake Ground Motions1This standard is issued under the fixed designation C1858;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 practice covers the installation requirements ofdirect hung suspended t-bar type ceiling systems intended toreceive gypsum panel products constructed as flat,single level,surrounded on all sides by a wall,bulk head,or soffit braced tothe building structure to resist the effects of earthquake groundmotions.1.2 Ceiling assembly shall not be intended to support liveloads.1.3 This standard addresses ceiling systems with dead loadsup to 10 lbs/ft2(48.8 kg/m2).1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)shall not be consideredas requirements of the standard1.6 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 standard safety and health practices and determine theapplicability of regulatory limitations prior to use.1.7 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:A641/A641M Specification for ZincCoated(Galvanized)Carbon Steel Wire2C635/C635M SpecificationfortheManufacture,Performance,and Testing of Metal Suspension Systemsfor Acoustical Tile and Lay-in Panel Ceilings3C645 Specification for Nonstructural Steel Framing Mem-bers4C754 Specification for Installation of Steel Framing Mem-bers to Receive Screw-Attached Gypsum Panel Products4C1177/C1177M Specification for Glass Mat Gypsum Sub-strate for Use as Sheathing4C1396 Specification for Gypsum Board4C1658/C1658M Specification for Glass Mat Gypsum Pan-els43.Terminology3.1 DefinitionsTerms shall be as defined in TerminologyC11.3.2 Definitions of Terms Specific to This Standard:3.2.1 counter sloping wire,nopposing suspension wireintended to counteract the force of an out of plumb suspensionwire and maintain alignment of the system.3.2.2 cross runner,nthe secondary support members orcross beams of a mechanical ceiling suspension system trans-ferring ceiling load to the main runner.3.2.3 diaphragm,nhorizontal system acting to transmitlateral forces to the vertical resisting elements.3.2.4 direct hung ceiling,nload carrying ceiling compo-nents that are fastened directly to structure.3.2.5 main runner,nthe primary or main beams(supports)of the ceiling suspension system.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 May 15,2017.Published May 2017.DOI:10.1520/C1858-172Annual ASTM Book of Standards,Vol.01.06.3Annual ASTM Book of Standards,Vol.04.06.4Annual ASTM Book of Standards Vol.04.01.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 3.2.6 t-bar ceiling,nmodular interlocking suspended ceil-ing system containing framing members with invertedT-shaped profiles.4.Summary of Practice4.1 This practice outlines the design and installation re-quirements of direct hung gypsum t-bar ceilings exempt fromlateral bracing in areas subject to seismic activity.5.Significance and Use5.1 This practice provides a standardized installation proce-dure for ceilings designed and installed as a diaphragm.Wheninstalled according to this practice,these ceilings have suffi-cient strength to resist seismic forces without lateral forcebracing.6.Materials6.1 Gypsum panel product sh