1、Designation: C1280 12Standard Specification forApplication of Gypsum Sheathing1This standard is issued under the fixed designation C1280; 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 parent
2、heses 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 the minimum requirements forand methods of application of gypsum sheathing for use as asubstrate for exterior wall cladding.
3、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 th
4、ickness 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).1.3.
5、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 w
6、ith 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 i
7、n 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.1.6 The text of this standard references footnotes whichprovide explanatory material. These footnotes shall
8、not beconsidered as requirements 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 re
9、gulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsC954 Specification for Steel Drill Screws for the Applica-tion of Gypsum Panel Products or Metal Plaster Bases toSteel Studs from 0.033 in. (0.84 m
10、m) to 0.112 in. (2.84mm) in ThicknessC955 Specification for Load-Bearing (Transverse andAxial) Steel Studs, Runners (Tracks), and Bracing orBridging for Screw Application of Gypsum Panel Productsand Metal Plaster BasesC1002 Specification for Steel Self-Piercing Tapping Screwsfor the Application of G
11、ypsum Panel Products or MetalPlaster Bases to Wood Studs or Steel StudsC1007 Specification for Installation of Load Bearing(Transverse and Axial) Steel Studs and Related Accesso-riesC1063 Specification for Installation of Lathing and Furringto Receive Interior and Exterior Portland Cement-BasedPlast
12、erC1396/C1396M Specification for Gypsum Board2.2 U.S. Department of Commerce Publication:PS20 American Softwood Lumber Standard33. Terminology3.1 Definitions: Definitions shall be in accordance withTerminology C11.3.2 Definitions of Terms Specific to This Standard:3.2.1 exterior cladding, na permane
13、nt material 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.3.2.4 horizontal application,
14、 na synonym for perpendicu-lar application.1This specification is under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and is the direct responsibilityof Subcommittee C11.03 on Specifications for theApplication of Gypsum and OtherProducts in Assemblies.Cur
15、rent edition approved April 1, 2012. Published May 2012. Originallyapproved in 1994. Last previous edition approved in 2011 as C1280 11. DOI:10.1520/C1280-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of A
16、STMStandards 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.1*A Summary of Changes section appears at the end of this standard.Copyr
17、ight ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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-pl
18、ied with the edges at right angles to the framing members; asynonym for horizontal application.3.2.7 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 thi
19、s specification or a referenced requirement.3.2.9 specify, vto mandate by an obligation of this stan-dard or a referenced document.3.2.10 vertical application, nsynonym for parallel appli-cation.3.2.11 water-resistive barrier, na permanent material be-hind an exterior wall cladding that is intended
20、to resist liquidwater that has penetrated the exterior covering from furtherintruding into the exterior wall assembly.3.2.12 weather-resistive barrier, na temporarily exposedprotective membrane that is intended to impede the penetrationof environmental elements until the installation of a permanentw
21、ater-resistive barrier and exterior cladding.4. Exposure After Installation4.1 Gypsum sheathing board provides a substrate, whichshall be covered by an exterior cladding or other weather-resistive barrier and is not intended for long-term exposure.Gypsum sheathing board shall not be exposed to the e
22、lementsfor more than 30 days after it has been installed. Gypsumsheathing shall be covered with a water-resistive barrier within30 days of being installed, if the exposure time is expected tobe more than 30 days.5. Materials and Manufacture5.1 Gypsum SheathingSpecification C1396/C1396M.5.1.1 Type X
23、(Special Fire-Resistant) Gypsum SheathingGypsum sheathing that provides a greater degree of fireresistance than regular gypsum sheathing as defined in Speci-fication C1396/C1396M.5.2 FastenersFasteners shall be as described in 5.2.1through 5.2.3. The fastener length shall be not less than thatspecif
24、ied in Table 1.5.2.1 NailsNails shall be not less than 12-gauge galva-nized,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 less than0.033 in. (0.84 mm) in thickness, shall meet the requirementsof Specifi
25、cation C1002.5.2.2.2 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 C954.5.2.2.3 Trim-head screws shall not be permitted for theattachment of gypsum sheathing.5.2.2.4 Screws for fastenin
26、g self-furred metal lath overgypsum sheathing as described in 8.2.7 shall be as specified inSpecification C1063.5.2.3 StaplesStaples shall be of galvanized steel, not lessthan 16-gauge,716-in. (11.1-mm) wide crown outside measure-ment. Legs shall have divergent points.5.3 Framing Members:5.3.1 Wood
27、FramingWood framing members shall con-form to PS20.5.3.2 Steel FramingLoad-bearing steel framing shallmeet the requirements of Specification C955.6. 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 wall
28、s.6.1.1 Wood framing shall be straight and true, attachedsecurely following accepted engineering practices and asrequired for the intended design. 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 b
29、e 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 their intended use and shall beinstalled in accordance with Specification C1007.7. Framing Alignment7.1 Framing members shall be installed so that the surfac
30、ewill be in an even plane, unless otherwise specified, after thegypsum sheathing has been applied.8. Cutting and Application of Gypsum Sheathing8.1 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
31、 cut with a sharp knife or other suitable tool whencutting by scoring. The gypsum sheathing shall be broken bysnapping the gypsum sheathing in 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 ne
32、at fitting joints when installed.8.1.3 Holes for pipes, fixtures, or other small openings shallbe scored on the face paper before removing the 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 c
33、ut neatly.8.2 Application of Gypsum Sheathing:8.2.1 Gypsum sheathing shall be fitted snugly around allwindow and door openings.TABLE 1 Minimum Fastener LengthsFramingTypeFastenerTypeSheathingThickness, in. (mm)MinimumFastenerLength, in. (mm)Wood nails12 (12.7) 112 (38)58 (15.9) 134 (45)screws12 (12.
34、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)C1280 1228.2.1.1 Sheathing 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
35、 will not contact the sheathing.8.2.2 All vertical end and edge joints shall abut over thecenters of framing members and shall be offset a minimum 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 f
36、t (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 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 d
37、esign or the exterior cladding specified.8.2.3.4 Control joints, other accessories, and metal plasterbase shall be fastened through gypsum sheathing 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
38、gypsum sheathing applied perpendicu-lar to framing members shall be covered with a weather-resistive barrier, or horizontal joints shall be sealed.8.2.5 Tongue and groove gypsum sheathing shall be appliedwith the long dimension perpendicular to framing members,with the grooved edges down, interlocki
39、ng the tongue of thepanel below without forcing.8.2.6 Fasteners shall be as specified in either 8.2.6.1 or8.2.6.2. As an alternate, other fasteners and fastener spacingshall be permitted when determined to provide sufficientout-of-plane capacity either by calculations or tests.8.2.6.1 Fasteners for
40、the application of gypsum sheathing towood framing shall be spaced not more than 7 in. (178 mm) oncenters along vertical ends or edges and intermediate supports.The length of fasteners shall be as indicated in Table 1.8.2.6.2 Fasteners for the application of gypsum sheathing tometal framing shall be
41、 spaced not more than 8 in. (203 mm) oncenter along vertical ends or edges and intermediate supports.The length of fasteners shall be as indicated in Table 1.8.2.6.3 Fasteners shall be located not less than38 in. (9.5mm) from the ends and edges of the gypsum sheathing.8.2.6.4 Gypsum sheathing shall
42、be held tight against theframing when driving fasteners.8.2.6.5 Fasteners 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.8.2.6.6 Screws shall be driven without stripping the framingmember around the
43、screw shank.8.2.6.7 Staples shall be driven with the crown parallel to 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 claddin
44、g over gypsum sheathinginstalled over framing members spaced not more than 16 in.(406 mm) on center, and the metal lath shall be installed inaccordance with Specification C1063 within 24 h after thegypsum sheathing, the gypsum sheathing shall be permitted tobe applied as specified in 8.2.7.1 and 8.2
45、.7.2, and fastening ofthe gypsum sheathing shall be completed with the 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
46、in place at each intermediate stud with a minimum oftwo fasteners per 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. Gypsums
47、heathing shall be fastened in place at each intermediate studwith fasteners spaced not more than 24 in. (610 mm) on center.9. Keywords9.1 exterior walls; gypsum; sheathingSUMMARY OF CHANGESCommittee C11 has identified the location of selected changes to this specification since the last issue,C1280
48、11, that may impact the use of this specification. (Approved April 1, 2012)(1) Changed the term weather-resistive barrier to water-resistive barrier in select locations.(2) Revised definition of weather-resistive barrier.(3) Updated definitions to include a definition for water-resistive barrier.(4)
49、 Deleted Note 1 following 4.1.C1280 123ASTM 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 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 or withd
