ASTM_C_475_-_C_475M_-_15.pdf

Designation:C475/C475M15Standard Specification forJoint Compound and Joint Tape for Finishing GypsumBoard1This standard is issued under the fixed designation C475/C475M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This specification covers all-purpose,taping and finish-ing joint compounds,paper joint tape,and glass-mesh jointtape.1.1.1 The joint materials used in this standard are designedto be used with gypsum board installed in accordance withSpecification C840.1.2 This specification also covers the minimum require-ments for an assembly of taping and all-purpose compound andjoint tape.1.3 The text of this specification references notes andfootnotes that provide explanatory material.These notes andfootnotes(excluding those in tables and figures)shall not beconsidered as requirements of the specification.1.4 The values stated in either inch-pound or SI(metric)units are to be regarded separately as standard.Within the text,the SI units are shown in parentheses.The values stated in eachsystem shall be used independent of the other.Values from thetwo systems shall not be combined.2.Referenced Documents2.1 ASTM Standards:2C11 Terminology Relating to Gypsum and Related BuildingMaterials and SystemsC474 Test Methods for Joint Treatment Materials for Gyp-sum Board ConstructionC840 Specification forApplication and Finishing of GypsumBoardD123 Terminology Relating to TextilesD3882 Test Method for Bow and Skew in Woven andKnitted FabricsF1615 Specification for Cautionary Labeling for Five-Gallon Open-Head Plastic Containers3.Terminology3.1 DefinitionsDefinitions shall be in accordance withTerminology C11.3.2 Definitions of Terms Specific to This Standard:3.2.1 glass-mesh joint-tape,na strip of multidirectionalglass yarn material designed to reinforce the joint between twogypsum boards.3.2.2 joint tape,na strip of material used to conceal andreinforce the joint between two gypsum boards.3.2.3 joint tape,self-adhering,na joint tape manufacturedto adhere directly to the substrate.3.2.3.1 DiscussionTapes having this quality do not requiremechanical or embedment means of attachment to the sub-strate.3.2.4 paper joint tape,na strip of paper reinforcingmaterial designed to be embedded in the joint compound and toreinforce the joint between two gypsum boards.3.2.5 skewness,nas defined in Terminology D123.4.Physical Properties4.1 GeneralThe physical properties shall be determined inaccordance with Test Methods C474,except as noted.4.2 Joint Compounds.4.2.1 Check CrackingNo cracks in the thinner half of thewedge and no deep fissure cracks in the thicker half of thewedge.4.2.2 PutrefactionNo putrefaction in less than four days.4.2.3 ShrinkageNot more than 35%by volume.4.3 Joint Tape:4.3.1 The following tests are required of all joint tape:4.3.1.1 WidthShall be not less than 178in.(48 mm)normore than 214in.(60 mm).The width of an individual rollshall vary not more than 6132in.(1 mm).4.3.1.2 ThicknessShall be not more than 0.012 in.(0.30 mm).1This specification is under the jurisdiction of ASTM Committee C11 onGypsum and Related Building Materials and Systems and is the direct responsibilityof Subcommittee C11.02 on Specifications and Test Methods for Accessories andRelated Products.Current edition approved June 1,2015.Published June 2015.Originallyapproved in 1961.Last previous edition approved in 2014 as C475/C475M 121.DOI:10.1520/C0475_C0475M-15.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.3.1.3 Tensile StrengthShall be not less than 30 lbf/in.(5.25 N/mm)in the cross direction.4.3.2 The following tests are required of paper joint tape:4.3.2.1 Dimensional StabilityShall expand not more than0.4%lengthwise and not more than 2.5%crosswise.4.3.3 The following test is required of glass-mesh joint tape:4.3.3.1 Skewness,when tested in accordance with TestMethod D3882,shall be not more than 8.75%.4.4 Assembly of Taping or All-Purpose Compound andPaper Joint Tape:4.4.1 Bond between the joint tape and the joint compoundshall be not less than 90%.4.4.2 Edge cracking shall be not more than 10%along theedges of the tape specimen.5.Sampling5.1 Sampling of Joint CompoundAt least 1%,but not lessthan one package or container shall be sampled and shall be soselected as to be representative of the shipment.The materialso obtained shall be thoroughl