ASTM_D_4897_-_D_4897M_-_01_2009.pdf

Designation:D4897/D4897M01(Reapproved 2009)Standard Specification forAsphalt-Coated Glass-Fiber Venting Base Sheet Used inRoofing1This standard is issued under the fixed designation D4897/D4897M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript 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 asphalt-impregnated andcoated glass-fiber base sheet with mineral surfacing on the topside and coarse mineral granules on the bottom side for use asthe first ply of a roofing membrane.These base sheets providefor the lateral release of pressure in roofing systems becausethey are not solidly attached and the coarse granular surfaceprovides an open,porous channel in the horizontal planebeneath the membrane.The base sheets shall be permitted to bewith or without perforations or embossings.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system 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.1.3 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 use.2.Referenced Documents2.1 ASTM Standards:2D146 Test Methods for Sampling and Testing Bitumen-Saturated Felts and Woven Fabrics for Roofing andWaterproofingD228 Test Methods for Sampling,Testing,and Analysis ofAsphalt Roll Roofing,Cap Sheets,and Shingles Used inRoofing and WaterproofingD1079 Terminology Relating to Roofing and Waterproofing3.Terminology3.1 DefinitionsFor definitions of terms used in this speci-fication,refer to Terminology D1079.4.Classification4.1 Type IIHeavy-duty asphalt-coated glass-fiber ventingbase sheet.5.Materials and Manufacture5.1 The mat shall be a thin porous sheet of uniformlydistributed glass fibers,with or without the addition of rein-forcing strands,or glass yarns,which are bonded with awater-resistant resinous binder.5.2 In the process of manufacture,the glass mat is impreg-nated and coated on both sides with a hot asphaltic coating withor without a mineral stabilizer and surfaced on the bottom sidewith coarse mineral granules embedded in an asphaltic coating.The top side shall be surfaced with fine mineral surfacing.5.3 The product shall be permitted to be embossed orunembossed on the bottom side.The product shall be permittedto contain holes designated for attachment with moppingasphalt.6.Physical Requirements,Dimensions,and Masses6.1 The material at the point of manufacture shall conformto the physical requirements in Table 1 and the dimensions andmasses in Table 2.6.2 The finished product shall not crack nor be so sticky asto cause tearing or other damage upon being unrolled attemperatures between 10 and 60C 50 and 140F.6.3 Pliability at 25 6 1C 77 6 2FAt least eight out often strips shall not crack when tested in accordance with TestMethods D228 except,for convenience,that the strips shall beconditioned in ambient conditions at 25 6 1C 77 6 2F forat least 30 min before testing over a 19-mm 34-in.radius.6.4 Loss and Behavior on Heating There shall be noflowing,sagging,or blistering of the asphalt coating whentested in accordance with Test Methods D228.1This specification is under the jurisdicton ofASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.04 on Felts,Fabrics and Bituminous Sheet Materials.Current edition approved June 15,2009.Published July 2009.Originallyapproved in 1989.Last previous edition approved in 2001 as D4897 01.DOI:10.1520/D4897_D4897M-01R09.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.Workmanship,Finish,and Appearance7.1 The glass mat shall be impregnated and shall show nowhite spots at any point.7.2 The coating shall be applied to each side to the edges ofthe sheet.The coating must be smooth.7.3 The top side shall be surfaced with mineral surfacing toprevent the roofing from sticking in the package.7.4 The bottom side shall be surfaced with coarse mineralmatter,at least 90%retained on a 212-m No.70 sieve,embedded in the asphalt coating.7.5 The finished material shall be free of visible externaldefects,such as holes,ragged or untrue edges,breaks,cracks