1、Designation: C 1280 04Standard Specification forApplication of Gypsum Sheathing1This standard is issued under the fixed designation C 1280; 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 pare
2、ntheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the minimum requirements forand methods of application of gypsum sheathing for use as asubstrate for exterior wall claddin
3、g.1.2 Details of construction for a specific assembly toachieve the required fire resistance shall be obtained fromreports of fire-resistance tests, engineering evaluations, orlistings from recognized fire testing laboratories.1.2.1 This specification shall govern where it is morestringent (size or
4、thickness of framing and size and spacing offasteners) than the fire-rated construction.1.3 Where sound control is required for a gypsum sheathingassembly, the details of construction shall be in accordancewith the acoustical test report of an assembly that has met therequired acoustical value(s).1.
5、3.1 This specification shall govern where it is morestringent (size or thickness of framing and size and spacing offasteners) than the sound-rated construction.1.4 Where resistance to racking loads or shear is requiredfor a gypsum sheathing assembly, the details of constructionshall be in accordance
6、 with the racking or shear test report ofan assembly that has met the required racking or shear value(s).1.4.1 This specification shall govern where it is morestringent (size or thickness of framing and size and spacing offasteners) than the racking or shear-tested construction.1.5 The values stated
7、 in inch-pound units are to be regardedas the standard. The SI (metric) values given in parentheses areapproximate and are provided for information purposes only.1.6 The text of this standard references footnotes whichprovide explanatory material. These footnotes shall not beconsidered as requiremen
8、ts of the standard.1.7 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 and health practices and determine the applica-bility of regulatory limitations prior to
9、use.2. Referenced Documents2.1 ASTM Standards:2C 11 Terminology Relating to Gypsum and Related Build-ing Materials and SystemsC 79/C 79M Specification for Gypsum Sheathing BoardC 954 Specification for Steel Drill Screws for the Applica-tion of Gypsum Panel Products or Metal Plaster Bases toSteel Stu
10、ds from 0.033 in. (0.84 mm) to 0.112 in. (2.84mm) in ThicknessC 955 Specification for Load-Bearing (Transverse andAxial) Steel Studs, Runners (Tracks), and Bracing orBridging for Screw Application of Gypsum Panel Productsand Metal Plaster BasesC 1002 Specification for Steel Self-Piercing TappingScre
11、ws for the Application of Gypsum Panel Products orMetal Plaster Bases to Wood Studs or Steel StudsC 1007 Specification for the Installation of Load Bearing(Transverse and Axial) Steel Studs and Related Accesso-riesC 1063 Specification for Installation of Lathing and Furringto Receive Interior and Ex
12、terior Portland Cement-BasedPlaster2.2 U.S. Department of Commerce Publication:PS20 American Softwood Lumber Standard33. Terminology3.1 Definitions: Definitions shall be in accordance withTerminology C 11.3.2 Definitions of Terms Specific to This Standard:3.2.1 exterior cladding, na permanent materi
13、al or systemthat impedes the transmission of environmental elements to thesheathing.3.2.2 fastener, nnails, staples, or screws used for applica-tion of the sheathing.3.2.3 framing member, nstuds, headers, bracing, andblocking that serve to receive the sheathing.1This specification is under the juris
14、diction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and is the direct responsibilityof Subcommittee C11.03 on Specifications for Application of Gypsum and OtherProducts in Assemblies.Current edition approved May 1, 2004. Published June 2004. Originallyapproved in 1994.
15、Last previous edition approved in 1999 as C 1280 - 99.2For 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.3Availa
16、ble from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.4 horizontal application, na synonym for perpendicu-lar a
17、pplication.3.2.5 parallel application, ngypsum sheathing appliedwith the edges parallel to the framing members; a synonym forvertical application.3.2.6 perpendicular application, ngypsum sheathing ap-plied with the edges at right angles to the framing members; asynonym for horizontal application.3.2
18、.7 require, vto mandate by a force outside this speci-fication, such as a building code, project specification, contract,or purchase order.3.2.8 specified, adjpertaining to a mandatory requirementof this specification or a referenced requirement.3.2.9 specify, vto mandate by an obligation of this st
19、an-dard or a referenced document.3.2.10 vertical application, nsynonym for parallel appli-cation.3.2.11 weather resistive barrier, na temporarily exposedprotective membrane that is intended to impede the penetrationof environmental elements until the installation of a permanentexterior cladding.4. E
20、xposure After Installation4.1 Gypsum sheathing board is a substrate that shall becovered by an exterior cladding or other weather-resistivebarrier and is not intended for long-term exposure. It shall notbe exposed to the elements for more than 30 days after it hasbeen installed. Gypsum sheathing sha
21、ll be covered with aweather-resistive barrier within 30 days if the exposure timewill be more than 30 days.NOTE 1Some building codes require an additional weather-resistivebarrier. The exterior face paper of the sheathing shall be dry prior toapplication of the additional weather-resistive barrier.5
22、. Materials and Manufacture5.1 Gypsum SheathingSpecification C 79/C 79M.5.1.1 Type X (Special Fire-Resistant) Gypsum SheathingGypsum sheathing that provides a greater degree of fireresistance than regular gypsum sheathing as defined in Speci-fication C 79/C 79M.5.2 FastenersFasteners shall be as des
23、cribed in 5.2.1through 5.2.3. The fastener length shall be not less than thatspecified in Table 1.5.2.1 NailsNails shall be not less than 12-gagegalvanized,716-in. (11.1-mm) diameter head.5.2.2 Screws:5.2.2.1 Screws for fastening gypsum sheathing to woodframing members, and to steel framing members
24、less than0.033 in. (0.84 mm) in thickness, shall meet the requirementsof Specification C 1002.5.2.2.2 Screws for fastening gypsum sheathing to steelframing members from 0.033 to 0.112 in. (0.84 to 2.84 mm) inthickness shall meet the requirements of Specification C 954.5.2.3 StaplesStaples shall be o
25、f galvanized steel, not lessthan 16-gage,716-in. (11.1-mm) wide crown outside measure-ment. Legs shall have divergent points.5.3 Framing Members:5.3.1 Wood FramingWood framing members shall con-form to PS20.5.3.2 Steel FramingLoad-bearing steel framing shallmeet the requirements of Specification C 9
26、55.6. Substrate, Surface Preparation6.1 The maximum spacing for framing members for gyp-sum sheathing shall be not more than 24 in. (610 mm) oncenter on walls.6.1.1 Wood framing shall be straight and true, attachedsecurely following accepted engineering practices and asrequired for the intended desi
27、gn. The surfaces to whichabutting edges or ends of gypsum sheathing are to be attachedshall be not less than 112-in. (38-mm) wide. The bearingsurface shall be not less than34 in. (19 mm) for internalcorners or angles.6.1.2 Load-bearing metal framing members shall be of theproper size and design for
28、their intended use and shall beinstalled in accordance with Specification C 1007.7. Framing Alignment7.1 Framing members shall be installed so that the surfacewill be in an even plane, unless otherwise specified, after thegypsum sheathing has been applied.8. Cutting and Application of Gypsum Sheathi
29、ng8.1 Cutting Gypsum Sheathing:8.1.1 The gypsum sheathing shall be cut by scoring andbreaking or by sawing, working from the face side. The facepaper shall be cut with a sharp knife or other suitable tool whencutting by scoring. The gypsum sheathing shall be broken bysnapping the gypsum sheathing in
30、 the reverse direction or bycutting the back paper with a knife or suitable tool.8.1.2 The cut edges and ends of gypsum sheathing shall betrimmed to obtain neat fitting joints when installed.8.1.3 Holes for pipes, fixtures, or other small openings shallbe scored on the face paper before removing the
31、 cutout with asaw or special tool designed for this purpose.8.1.4 Where gypsum sheathing meets projecting surfaces,the gypsum sheathing shall be scribed and cut neatly.8.2 Application of Gypsum Sheathing:8.2.1 Gypsum sheathing shall be fitted snugly around allwindow and door openings.8.2.1.1 Sheathi
32、ng joints shall be offset a minimum of 4 in.(100 mm) from the edge of any opening.8.2.1.2 Gypsum sheathing shall be flashed at openings sothat water intrusion will not contact the sheathing.TABLE 1 Minimum Fastener LengthsFramingTypeFastenerTypeSheathingThickness, in. (mm)MinimumFastenerLength, in.
33、(mm)Wood nails12 (12.7) 112 (38)58 (15.9) 134 (45)screws12 (12.7) 114 (32)58 (15.9) 114 (32)staples12 (12.7) 112 (38)58 (15.9) 134 (45)Steel screws12 (12.7) 1 (25)58 (15.9) 114 (32)C 1280 0428.2.2 All vertical end and edge joints shall abut over thecenters of framing members and shall be offset a mi
34、nimum ofone framing space between adjacent rows of gypsum sheath-ing.8.2.3 Control Joints:8.2.3.1 Control joints shall be provided in wall runs exceed-ing 30 ft (9100 mm) in length. The distance between controljoints shall be not more than 30 ft (9100 mm).8.2.3.2 Control joints shall be installed in
35、 walls whereverthere is a building construction joint or where required.8.2.3.3 The location of the control joints shall be as requiredby either the building design or the exterior cladding specified.8.2.3.4 Control joints, other accessories, and metal plasterbase shall be fastened through gypsum sh
36、eathing to framingmembers.8.2.4 Gypsum sheathing, 4-ft (1220-mm) wide, shall beapplied either parallel or perpendicular to framing members.8.2.4.1 Square edge gypsum sheathing applied perpendicu-lar to framing members shall be covered with a weather-resistive barrier, or horizontal joints shall be s
37、ealed.8.2.5 Tongue and groove gypsum sheathing shall be appliedwith the long dimension perpendicular to framing members,with the grooved edges down, interlocking the tongue of thepanel below without forcing.8.2.6 Fasteners shall be spaced not more than 8 in. (203mm) on center along vertical ends or
38、edges and intermediatesupports. The length of fasteners shall be as indicated in Table1.8.2.6.1 Fasteners shall be located not less than38 in. (9.5mm) from the ends and edges of the gypsum sheathing.8.2.6.2 Gypsum sheathing shall be held tight against theframing when driving fasteners.8.2.6.3 Fasten
39、ers shall be driven so that the heads are at orslightly below the surface of the gypsum sheathing withoutbreaking the face paper or fracturing the core.8.2.6.4 Screws shall be driven without stripping the framingmember around the screw shank.8.2.6.5 Staples shall be driven with the crown parallel to
40、 theframing member.8.2.7 Application of Gypsum Sheathing Under Self-FurredMetal LathWhere fire resistance or shear resistance is notrequired, and when metal lath and portland cement plaster areto be applied as the exterior cladding over gypsum sheathinginstalled over framing members spaced not more
41、than 16 in.(406 mm) on center, and the metal lath shall be installed inaccordance with Specification C 1063 within 24 h after thegypsum sheathing, the gypsum sheathing shall be permitted tobe applied as specified in 8.2.7.1 and 8.2.7.2, and fastening ofthe gypsum sheathing shall be completed with th
42、e attachmentof the self-furred metal lath.8.2.7.1 For 2-ft (610-mm) wide sheathing installed in ac-cordance with 8.2.5, vertical ends of gypsum sheathing shall befastened in accordance with 8.2.6. Gypsum sheathing shall befastened in place at each intermediate stud with a minimum oftwo fasteners per
43、 board spaced not more than 2 in. (50 mm)from opposite edges.8.2.7.2 For 4-ft (1220-mm) wide sheathing installed inaccordance with 8.2.4, vertical ends or edges of gypsumsheathing shall be fastened in accordance with 8.2.6. Gypsumsheathing shall be fastened in place at each intermediate studwith fas
44、teners spaced not more than 24 in. (610 mm) on center.9. Keywords9.1 exterior walls; gypsum; sheathingASTM 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 de
45、termination of the validity of any such patent rights, and the riskof 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
46、or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel t
47、hat your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 1280 043
