1、Designation: D 7281 07Standard Test Method forDetermining Water Migration Resistance Through RoofMembranes1This standard is issued under the fixed designation D 7281; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of watermigration resistance of roof membranes including built-up roofmembranes
3、, modified bitumen, and single ply roof membranes.The procedures were developed to determine the potential forleakage of water through the roof membranes resulting from astanding head of water and when pressurized with air from theunderside.1.2 The values stated in SI units are to be regarded as the
4、standard. The values given in parentheses are for informationonly.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 app
5、lica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2G 154 Practice for Operating Fluorescent Light Apparatusfor UV Exposure of Nonmetallic Materials3. Terminology3.1 Definitions:3.1.1 adhereto cause two surfaces to be held together byadhesion. Roof membranes
6、 are often “partially-” or “totally-adhered” to a substrate.3.1.2 battena narrow band or plate that is used to fasten orprevent the displacement of a single ply membrane.3.1.3 delaminationseparation between lamination orbonded material or component; for example, laminated layersof rigid insulation o
7、r the felt plies in a built-up roof.3.1.4 field seama splice made in the field of a single plymembrane that joins two sheets together using an adhesive,splicing tape, heat, or solvent-welding.3.1.5 mechanically fastened membranesa single ply orbase ply (part of a multi-layer system) membrane that ha
8、s beenpositively attached at intervals to the substrate, usually withfasteners and/or other mechanical devices, such as battens.3.1.6 NPTNational Pipe Thread.4. Summary of Test Method4.1 Roofing membranes are conditioned and installed in theleakage test apparatus (Fig. 1). A 152-mm (6-in.) head of w
9、ateris maintained over the sample for 7 days at ambient conditions,21C (70F). At the end of the 7 day period, air shall beintroduced into the bottom section of the apparatus, increasingthe pressure to 6.9 kPa (1 psig) and immediately released toambient conditions. This cycle is repeated 25 times.5.
10、Significance and Use5.1 This test method provides a means of evaluating roofmembranes, seams, and laps for resistance to water migrationfrom standing water on the roof. This test method evaluatesroof membranes when first applied and also after simulateddeterioration caused by the ultraviolet energy
11、of the sun.6. Apparatus6.1 The test apparatus consists of top section, a supportplate, and a bottom section, which are clamped together withthe sample being evaluated placed as a diaphragm between thetop sections and the support plate.6.1.1 The top section consists of a 203-mm (8-in.) diameter,6-mm
12、(14-in.) wall thickness 3 203-mm (8-in.) length of clearacrylic pipe, which is cemented to a 305-mm (12-in.) diameterflange.6.1.2 The support plate is a round poly(vinyl chloride) plate,6-mm (14-in.) thick and a 241-mm (912-in.) diameter with6-mm (14-in.) diameter holes spaced 25 mm (1 in.) on cente
13、r.6.1.3 The bottom section consists of a 305-mm (12-in.)diameter flange attached to a 203-mm (8-in.) diameter, 6-mm(14-in.) wall thickness 3 152-mm (6-in.) length of clear acrylicpipe, which is fabricated with two threaded holes 6 mm (14 in.)NPT. These holes are used after the test apparatus section
14、s areclamped together, with the roof cover between them. One holeprovides a connection point for air pressure to be increased and1This test method is under the jurisdiction of ASTM Committee D08 on Roofingand Waterproofing and is the direct responsibility of Subcommittee D08.20 onRoofing Membrane Sy
15、stems.Current edition approved May 1, 2007. Published June 2007.2For 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 websi
16、te.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.released; the other hole provides a connection for the pressuregauge. A 305-mm (12-in.) diameter bottom cap is adhered tothe bottom section.6.1.4 The gasket material consists of a no
17、n-absorbent,flexible closed cell foam. A silicone sealant is permitted to beused to further aid in preventing water from leaking around theperimeter of the flange of the test apparatus.FIG. 1 Leakage Test ApparatusD72810727. Sampling, Test Specimens, and Test Units7.1 Aroof membrane 0.6 3 1.2m(23 4
18、ft) is selected fromthe material to be tested. A standard field seam, if present, isincorporated per the manufacturers instructions, in the centerof the sample in the 1.2 m (4 ft) direction.7.2 After a preparation and conditioning (laboratory cure),if required, the roof membrane is cut to produce tw
19、o 305 3 610mm (12 3 24 in.) samples with a standard field joint in the 305mm (12 in.) direction.8. Conditioning8.1 A 305 3 610 mm (12 3 24 in.) roof membrane samplewith a standard field joint is conditioned (laboratory cure) atambient conditions for up to 28 days.8.2 A piece of roof membrane 305 3 6
20、10 mm (12 3 24 in.)with a standard field joint is conditioned (weathered) for 1000h in a fluorescent ultraviolet condensation-type weather appa-ratus conforming to Practice G 154. The sample will beexposed to UV radiation using a UVA 340 lamp. Exposure tomoisture shall be by condensation method. The
21、 cycle timesshall be set for 8 h of UV and8hofcondensation. The lighttemperature shall be set at 63 6 3C (145 6 5F) and thecondensation temperature shall be set at 50 6 3C (122 65F). Upon removal from the weather apparatus, the sample isagain inspected for damage.9. Procedure9.1 Two 254-mm (10-in.)
22、diameter samples are then cutfrom conditioned specimens (see Section 8) and clamped inplace between the flanges of the test apparatus or between theupper section and the support plate if required. A 152 mm (6in.) head of water is maintained over the specimen for 7 daysat ambient conditions, 21C (70F
23、). If a standard field seam ispresent, it shall be included in the specimen. At the end of the7 day period, air is introduced into the bottom section of theapparatus, increasing the pressure to 6.9 kPa (1 psig) andimmediately released to ambient conditions. This cycle isrepeated 25 times. The sample
24、 is then inspected for damageand leakage.10. Interpretation of Results10.1 There shall be no sign of water leakage during the 7day test period.11. Report11.1 Report the following information:11.1.1 Materials used in sample construction.11.1.2 Date and specifics of sample construction.11.1.3 Date and
25、 time that sample was placed in the weath-ering apparatus.11.1.4 Date and time that sample was removed from theweathering apparatus.11.1.5 Date and time sample placed in leakage test appara-tus.11.1.6 Date and time of air pressure cycles.11.1.7 Determination of pass/fail of sample.11.1.8 If any wate
26、r is or is not present on the underside ofthe membrane.11.1.9 Any notable comments.12. Precision and Bias12.1 The test result is determined by the visual pass/fail(go/no go) observation.12.2 No information is presented about either the precisionor bias of this test method for measuring water migrati
27、onresistance since the test result is non-quantitative.13. Keywords13.1 condensation; laminated; roof membrane; ultravioletradiation; water leakage; weatheringASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stand
28、ard. 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 review
29、ed every five years andif not revised, either reapproved 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
30、 technical committee, which you may attend. If you feel that 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).D7281073
