1、Designation: C844 04 (Reapproved 2010)Standard Specification forApplication of Gypsum Base to ReceiveGypsum Veneer Plaster1This standard is issued under the fixed designation C844; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers t
3、he minimum requirements for,and methods of, application of gypsum veneer base for gypsumveneer plasters.1.2 Gypsum veneer base shall not be used as a base fordirect adhesive application of ceramic, metal, or plastic tile inareas exposed to abnormal moisture or humidity or tempera-ture.1.3 Details of
4、 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.1.4 Where a specific degree of sound control is required forveneer plaster assemblies and
5、 constructions, details of con-struction shall be in accordance with official reports of testsconducted in recognized sound testing laboratories in accor-dance with the applicable sound tests, Test Method C423, TestMethod E90, or Test Method E492.1.5 Where this specification is more stringent (size
6、orthickness of framing; spacing of fasteners) than the fire-ratedconstruction, this specification shall govern; otherwise, theconstruction described in the fire test report shall govern.1.6 Unheated spaces above gypsum veneer base ceilingsshall be properly ventilated (see Appendix X3).1.7 The values
7、 stated 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.1.8 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding
8、 those in tables and figures) shall not be consideredas requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsC423 Test Method for Sound Absorption and Sound Ab-sorption Coefficients by the Reverberation Ro
9、om MethodC514 Specification for Nails for the Application of GypsumBoardC587 Specification for Gypsum Veneer PlasterC588/C588M Specification for Gypsum Base for VeneerPlasters3C754 Specification for Installation of Steel Framing Mem-bers to Receive Screw-Attached Gypsum Panel ProductsC954 Specificat
10、ion for Steel Drill Screws for the Applica-tion of Gypsum Panel Products or Metal Plaster Bases toSteel Studs from 0.033 in. (0.84 mm) to 0.112 in. (2.84mm) in ThicknessC955 Specification for Load-Bearing (Transverse andAxial) Steel Studs, Runners (Tracks), and Bracing orBridging for Screw Applicati
11、on of Gypsum Panel Productsand Metal Plaster BasesC1002 Specification for Steel Self-Piercing Tapping Screwsfor the Application of Gypsum Panel Products or MetalPlaster Bases to Wood Studs or Steel StudsC1007 Specification for Installation of Load Bearing(Transverse and Axial) Steel Studs and Relate
12、d Accesso-riesC1047 Specification for Accessories for Gypsum Wallboardand Gypsum Veneer BaseC1546 Guide for Installation of Gypsum Products in Con-cealed Radiant Ceiling Heating Systems1This specification is under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Sys
13、tems and is the direct responsibilityof Subcommittee C11.03 on Specifications for theApplication of Gypsum and OtherProducts in Assemblies.Current edition approved May 15, 2010. Published September 2010. Originallyapproved in 1978. Last previous edition approved in 2004 as C84404. DOI:10.1520/C0844-
14、04R10.2For 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.3Withdrawn. The last approved version of this historica
15、l standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E90 Test Method for Laboratory Measurement of AirborneSound Transmission Loss of Building Partitions and Ele-mentsE492 Test Method for Laboratory
16、 Measurement of ImpactSound Transmission Through Floor-Ceiling AssembliesUsing the Tapping Machine2.2 American Softwood Lumber Standard:PS20 American Softwood Lumber Standard43. Terminology3.1 DefinitionsDefinitions shall be in accordance withTerminology C11.3.2 Definitions of Terms Specific to this
17、 Standard:3.2.1 base plyfirst ply of gypsum base in multiple plyapplication.3.2.2 face plyouter or visible layer of gypsum base inmultiple ply application.3.2.3 fastener, nnails, screws, or staples used for theapplication of the gypsum base or backing board.3.2.4 framing member, nthat portion of the
18、 framing,furring, blocking, etc., to which the gypsum base is attached.Unless otherwise specified, the surface to which abutting edgesor ends are attached shall be not less than 112 in. (38 mm)wide for wood members, not less than 114 in. (32 mm) widefor steel members, and not less than 6 in. (152 mm
19、) wide forgypsum studs. For internal corners or angles, the bearingsurface shall be not less than34 in. (19 mm).3.2.5 parallel application, ngypsum base applicationwhere the gypsum base edge is applied parallel to the framingmembers.3.2.6 perpendicular application, ngypsum base applica-tion where th
20、e gypsum base edge is applied at right angles tothe framing members.4. Materials4.1 Materials shall conform to the respective specificationsand standards and to the requirements specified herein.4.2 Gypsum Base for Veneer Plasters (hereinafter referredto as “gypsum base”)Specification C588/C588M.4.3
21、 Gypsum Backing Board or CoreboardSpecificationC442.4.4 Special Fire-Retardant Gypsum BaseSpecificationC588/C588M, Type X.4.5 Foil-Backed Gypsum BaseSpecification C588/C588M.4.6 Gypsum Veneer PlasterSpecification C587.4.7 NailsSpecification C514.4.8 Screws:4.8.1 Non-load bearing steelSpecification C
22、1002.4.8.2 Load bearing steelSpecification C954.4.9 StaplesNo. 16 USS gage 0.063 in. (1.6-mm) flattenedgalvanized wire with716-in. (11.1-mm) wide-crown minimumoutside measure and divergent points. Staples shall be usedonly for the base ply of two-ply application over woodframing.4.10 Steel Framing,
23、Non-load bearingSpecification C645for the specified design criteria.4.11 AccessoriesSpecification C1047.4.12 Adhesive:4.12.1 For application of gypsum base to steel framing, theadhesive shall be as recommended by the manufacturer of thegypsum base.4.13 Steel Framing Load BearingSpecification C955.4.
24、14 Wood FramingAmerican Lumber Softwood Stan-dard PS20.5. Delivery of Materials5.1 All materials shall be delivered in the original packages,containers, or bundles bearing the brand name and manufac-turer (or supplier) identification.6. Shipping, Handling and Storage6.1 Gypsum board shall be shipped
25、 so as to be kept dry.6.2 Gypsum board shall be stored so as to be kept dry,preferably inside a building, under a roof. Gypsum board shallbe neatly stacked flat with care taken to prevent sagging ordamage to edges, ends, and surfaces.6.3 Where necessary to store gypsum board outside, it shallbe stac
26、ked flat, off the ground, supported on a level platformand fully protected from weather and direct sunlight exposure.6.4 Prior to application, the building exterior shall be soenclosed to protect the gypsum base from exposure to weatherand direct sunlight.NOTE 1The bond of alkaline veneer plaster to
27、 gypsum base will beimpaired if the base is exposed to direct light or sunlight for extendedperiods.7. Environmental Conditions7.1 Application of Gypsum Base and AdhesivesA roomtemperature of not less than 40 F (4 C) shall be maintainedduring application of gypsum base except when adhesive isused fo
28、r the attachment of gypsum base. For the bonding ofadhesive, a room temperature of not less than 50 F (10 C)shall be maintained for 48 h prior to application and continu-ously thereafter until adhesive is completely dry. When atemporary heat source is used, the temperature shall not exceed95 F (35 C
29、) in any room or area. Adequate ventilation shallbe maintained in the working area during the application andadhesive curing process.8. Application of Gypsum Base8.1 General Requirements:8.1.1 Installation of steel framing shall be in accordancewith applicable Specifications C754 or C1007 except whe
30、resuperseded by requirements of Table 1.NOTE 2For general wood framing requirements, see Appendix X2.8.1.2 Method of CuttingThe gypsum base shall be cut byscoring and breaking or by sawing, working from the face side.When cutting by scoring, the face shall be cut with a knife orother suitable tool a
31、nd the gypsum base snapped back awayfrom the cut face. The back shall be broken by snapping thegypsum base in the reverse direction, or by cutting with a knifeor other suitable tool.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 2089
32、9-1070, http:/www.nist.gov.C844 04 (2010)28.1.3 All cut edges and ends of the gypsum base shall besmoothed to obtain neat jointing. Cut-outs for pipes, fixtures,or other small openings on the face and back of the base shallbe scribed in outline before removing or cut out with a saw orother suitable
33、tool. The gypsum base shall be scribed where itmeets projecting surfaces. Base shall be brought lightly intocontact with adjacent panels but not forced into place.Abuttingends and edges shall fit neatly.8.1.4 When gypsum base is to be applied to both ceiling andwalls, the base shall be applied to th
34、e ceiling and then to thewalls.8.2 Fastening, Mechanical:8.2.1 The gypsum base shall be held in firm contact with theunderlying support while driving any fastener.8.2.2 Fastener application shall proceed from the center ofthe field of the gypsum base to the ends and edges or shallbegin along one edg
35、e and proceed toward the other edge.8.2.3 Except where required for fire rating, structural per-formance, or other special considerations, fastening to top orbottom plates shall not be required.8.2.4 Fasteners shall be spaced not less than38 in. (9.5 mm)from the edges and ends of the gypsum base. Fa
36、steners used atedges or at base ends in horizontal application shall not bemore than 1 in. from edges or ends.8.2.5 Nails and screws shall be driven to a point flush withthe gypsum base surface without breaking the surface paper ordamaging the surrounding gypsum core and without strippingthe framing
37、 member around the screws.8.2.6 Staples shall be driven so that both legs penetrate thesupport member and the crown bears tightly against thebacking board, but does not cut into the face paper. The stapleshall be driven with the crown parallel to framing members.Staples shall be used only for the fi
38、rst ply in two-ply gypsumbase systems.8.2.7 Penetration of mechanical fasteners into supportingframing members shall be not less than:Nails Screws StaplesWood:78 in. (22 mm)58 in. (15 mm)58 in. (15 mm), each legSteel: .38 in. (9 mm) .8.3 Control Joints8.3.1 Control joints shall be installed in ceili
39、ngs more than2500 ft2(232 m2) in area that are constructed with perimeterrelief. The distance between control joints shall be not morethan 50 ft (15 m) in either direction.8.3.2 Ceilings of more than 900 ft2(85 m2) in area con-structed without perimeter relief shall have control jointsinstalled with
40、 spacing not to exceed 30 ft (9 m) in eitherdirection.8.3.3 Control joints shall be installed where ceiling framingor furring changes direction or where construction joints occurin the base building construction. In partitions, walls, or wallfurring, the distance between control joints shall be not
41、morethan 30 ft (9 m).8.3.4 A ceiling height door frame, installed in accordancewith the spacing requirements set forth in 8.3, functions as acontrol joint.9. Application of Single-Ply Gypsum Base9.1 The maximum spacing of framing members for single-ply gypsum base construction shall be not more than
42、 thoseshown in Table 1.9.2 In single-ply installation, all ends and edges of gypsumbase shall occur over framing members or other solid backingexcept where treated joints occur at right angles to framing orfurring members.9.3 Joints on opposite sides of a partition shall be arrangedto occur on diffe
43、rent framing members.9.4 Fasteners (Single Ply Application):9.4.1 Nail SpacingSpace nails a maximum of 7 in. (178mm) on centers on the ceiling and a maximum of 8 in. (203mm) on centers on the walls.9.4.2 Double NailingNails shall be spaced as shown inFig. 1 and applied as follows:9.4.2.1 Starting at
44、 the center of the base, nails shown assolid dots shall be applied by row starting with row 1, thenrows 2 and 2A, 3 and 3A, 4 and 4A. Base shall be kept tightagainst the framing throughout the procedure.9.4.2.2 Using the procedure in 9.4.2.1, second nails shownby circles shall be applied.9.4.2.3 As
45、an alternative procedure, second nails shall bepermitted to be applied immediately after all first nails in eachindividual row have been driven in accordance with 9.4.2.1.9.4.2.4 Single nails shall be used on the perimeter of thebase.NOTE 3It may be necessary to reset the first nails in each row aft
46、er thesecond nails have been set.9.4.3 Nails for single-ply application over wood membersshall be as follows:TABLE 1 Maximum Framing SpacingSingle-ply Base (Thickness), in. (mm) Application to FramingMaximum On Center Spacing ofFraming, in. (mm)Ceilings:12 (12.7)12 (12.7)A58 (15.9)Bparallelperpendic
47、ularperpendicular16 (406)24 (610)24 (610)Sidewalls:38 (9.5)Cperpendicular 16 (406)12 (12.7) parallel 16 (406)12 (12.7)Aperpendicular 24 (610)58 (15.9)Bparallel or perpendicular 24 (610)A 12-in. (12.7-mm) gypsum base applied perpendicular on 24-in. (610-mm) on centers framing shall be considered to b
48、e minimum construction.BFor58-in. (15.9-mm) base, perpendicular on ceilings and either perpendicular or parallel on sidewalls at 24-in. (610-mm) on centers spacing, only two-componentveneer plaster or special joint reinforcement, as recommended by the gypsum veneer plaster manufacturer, shall be use
49、d.C 38-in. (9.5-mm) gypsum base shall be used over wood framing with two-component veneer plaster systems only.C844 04 (2010)3Gypsum Base Thickness, in. (mm) Nails, in. (mm)38 (9.5) 114 (32)12 (12.7) 138 (35)58 (15.9) 112 (38)9.4.4 Where a specific degree of fire resistance is requiredfor gypsum board assemblies and constructions, nails of sameor larger length, shank diameter, and head bearing area, asthose described in the applicable fire test report shall be used.9.4.5 Screw SpacingScrews shall be spaced not more than1
