1、Designation: C1858 17aStandard 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 i
2、mmediately 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 T
3、his 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
4、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
5、 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
6、(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 safety, health, and e
7、nvironmental practices and deter-mine the applicability 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 Sta
8、ndards, 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 Wire2C645 Specification for Nonstructural Steel Framing Mem-bers4C754 Speci
9、fication 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-els4E3090/E3090M Test Methods f
10、or Strength Properties ofMetal Ceiling Suspension Systems33. 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 suspensionwir
11、e 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.
12、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 Syst
13、ems and is the direct responsibility ofSubcommittee C11.03 on Specifications for the Application of Gypsum and OtherProducts in Assemblies.Current edition approved Oct. 1, 2017. Published November 2017. Originallyapproved in 1991. Last previous edition approved in 2017 as C1858 17. DOI:10.1520/C1858
14、-17A.2Annual ASTM Book of Standards,Vol.01.06.4Annual ASTM Book of StandardsVol.04.01.3Annual ASTM Book of Standards,Vol.04.06.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with
15、 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.13.2.6 t-bar ceiling, nmodular interlocking
16、 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 Use
17、5.1 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 shall co
18、nform to the require-ments of Specifications C1177/C1177M, C1396, and C1658/C1658M.6.2 Hanger wire shall conform to the requirements ofSpecification A641/A641M.6.2.1 For tributary ceiling areas not more than 16 ft2(1.5 m2) and less than 6 lb/ft2(2.7 kg m2), a minimum No.12-gauge (2.9 mm) galvanized,
19、 soft annealed, mild steel wireshall be used. For ceiling weights greater than 6 lb/ft2(2.7 kg m2), but not more than 10 lb/ft2(4.6/m2), see Specifi-cation C754 Table 6.6.3 Grid members shall conform to the requirements ofSpecification C645.7. Installation7.1 The installation method described in thi
20、s practice islimited to flat, single level designs surrounded on all sides bya wall, bulkhead, or soffit braced to the building structure toresist potential seismic forces imposed by the ceiling.7.2 Securing Hanger to Structure:7.2.1 Secure suspension wire to the building structure usinghanger attac
21、hment device suitable to carry the tributary verticalload of the ceiling system.7.2.2 Each suspension wire shall not hang more than one insix out of plumb unless a counter sloping wire or horizontalbracing is provided. See Fig. 1 for allowable counter slopingmethods.7.2.3 Locate vertical suspension
22、wires no more than 24 in.from the perimeter on all main runners.7.2.4 Local kinks or bends shall not be made in hanger as ameans of leveling main runners.7.2.5 In installations where the hanger wires are wrappedthrough main runners, the wire loops shall be tightly wrappedand sharply bent to prevent
23、any vertical movement or rotationof the member within the loops. The wire shall be wrappedaround itself a minimum of three full turns (360 each) withina 3-in 75 mm length. For safety purposes, the bottom of thehanger wires shall either be cut close to the vertical portion ofthe wire or shall be bent
24、 upward parallel to the vertical portionof the hanger wire.7.2.6 Hangers formed from galvanized sheet metal stockshall be suitable for suspending main runners from an existingstructure provided that the hangers do not yield, twist or allowsubsequent downward movement of the main runners due toimpose
25、d vertical ceiling loads.7.3 Perimeter:7.3.1 Terminal ends of grid members at the perimeter shallbe fastened to perimeter angle/channel on all surrounding wallswith fasteners appropriate for the wall substrate.7.3.2 Perimeter angle/channel shall provide a surface toaccept screw attachment of the gyp
26、sum panel product.7.3.3 Perimeter angle/channel shall be fastened into struc-tural element of the perimeter.7.4 Grid Members:7.4.1 Main Runner and Cross Runners shall be spaced tocarry the vertical load without exceeding a deflection limit ofL/240.7.4.2 Manufacturer shall provide sufficient data thr
27、ougheither calculations or testing to Specification E3090/E3090Mto verify vertical load carrying design capacity of the gridmembers.7.4.3 Vertical support hanger wire spaced greater than 3 in.(75 mm) from fire expansion relief cutouts shall be permitted ifload performance has been evaluated at the g
28、reater distance.7.4.4 Seismic separation joints are not required for sus-pended gypsum board grid systems designed within the scopeof this standard8. Substantiation8.1 All seismic installations not within the scope of thispractice shall be subject to evaluation by a licensed engineer.9. Drawings and
29、 Specifications9.1 The construction drawings shall clearly identify allceiling components. When this standard is referenced in adrawing, this standard shall be considered part of the require-ments of the drawing to the prescribed extent of such reference.Where differences occur between provisions of
30、 this standardand referenced code, the provisions of the code shall apply.Deviations or variation shall be shown or defined in detail.10. Keywords10.1 earthquake; grid ceilings; gypsum board ceiling sus-pension; seismic; seismic restraint; suspended gypsum boardceiling; t-barC1858 17a2FIG. 1 Allowab
31、le Counter Sloping MethodsC1858 17a3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the ris
32、kof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of thi
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