1、Designation: D7120/D7120M 10Standard Guide forEvaluation and Preparation of Roof Membranes for CoatingApplication1This standard is issued under the fixed designation D7120/D7120M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the
2、 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.1. Scope1.1 This guide covers the procedures for evaluating andpreparing non-aggregate surfaced membranes for the applica
3、-tion of a coating. It does not address design, construction, orinstallation issues regarding the roof assembly or the roofmembrane. It is not an application guide for roof coatings.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stat
4、ed 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.
5、 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. Terminology2.1 Definitions:2.1.1 adequate drainage, nthe drainage condition inwhich consideration has been made for a
6、ll loading deflectionsof the deck, and additional roof slope has been provided toensure drainage of the roof area within 48 h of rainfall.2.1.2 contaminant, nany substance which will adverselyeffect the adhesion of a coating.2.2 Contaminant List:2.2.1 air/water-borne surface contaminant, nany of sev
7、-eral types of external source contaminants that accumulate ontop surface of a roof. Surface contaminants come from one ofthe following sources: (1) particulate and liquid emissions frombuilding interior operations, (2) airborne vegetable and mineralparticles, and (3) oils, greases, and chemicals fr
8、om industrialand food service operations.2.2.2 chemical barrier, na barrier formed by reactivematerials either acid, alkali, or solvent, which inhibits theadhesion of surface coatings.2.2.3 exudate, na glossy film that forms on the surface ofan atactic polypropylene (APP) membrane. Exudates inhibitc
9、oating adhesion and they can bleed through and stain thecoating surface.2.2.4 loose mineral granules, nsee mineral granules,disattached mineral granules.2.2.5 moisture, nsurfaces to be coated must be clean anddry.2.2.6 organic barrier, nsee organic, any of several bio-logical growths, usually algae
10、or fungus, which act as a barrierbetween an APP roof membrane and a coating.2.2.7 release and/or anti-block agent, nsee parting agent,any of several mineral or waxy materials which are typicallyapplied to an APP sheet during the manufacturing process toprevent the sheet from sticking to itself while
11、 in the roll.2.2.8 surface oxidate, na barrier film, which forms on thesurface of an unprotected smoothAPP sheet during weathering.3. Significance and Use3.1 This guide outlines the general procedures necessary toevaluate and prepare a roof membrane for the application of aliquid surface coating.3.2
12、 This guide is not all inclusive; this guide is intended tosupplement detailed instructions from manufacturers andsafety requirements required by law.4. General Surface Conditions4.1 Lack of adequate drainage will have an adverse effect onroof components and will lead to premature failure of liquida
13、pplied coatings.4.2 It is important to determine the area(s) affected byadverse surface conditions. Specific surface preparation op-tions can be determined after the membrane has been evaluatedand subsequent adhesion tests performed.4.3 Multiple surface preparation techniques may be requiredto prepa
14、re the surface of an APP modified bitumen to receivea coating.1This guide is under the jurisdiction of ASTM Committee D08 on Roofing andWaterproofing and is the direct responsibility of Subcommittee D08.20 on RoofingMembrane Systems.Current edition approved July 1, 2010. Published July 2010. DOI: 10
15、.1520/D7120_D7120M-10.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Roof Surface Evaluation5.1 The roof membrane surface evaluation shall be con-ducted prior to the application of a surface coating. Surfaceevaluation will assist
16、 in determining the type of preparationrequired to achieve adhesion between the coating and the APPmodified bitumen material.5.1.1 Remove anything that will inhibit the adhesion of thecoating.5.1.2 Perform a “cloth tape evaluation” to determine thepresence and type of contaminants on the roof surfac
17、e accord-ing to the following procedure. On large surfaces, evaluateseveral locations.5.1.3 Avoid making evaluations on windy days or whenmoisture is present in any form.5.1.4 Clean the roof surface, as necessary, by the methodappropriate methods in Section 6.5.1.4.1 White Cloth Evaluation:5.1.4.2 M
18、aterialWhite wool felt, velvet, or velveteen.5.1.4.3 ProcedureWrap the fabric around the index fin-gertip and then make a 50 to 75-mm 2 to 3-in. stroke withmedium pressure on the surface being evaluated. Determinethe presence or absence of contamination using this evaluationtechnique. If no contamin
19、ation is present, proceed with thecoating operation.NOTE 1Medium pressure can be quantified by placing the finger on abalance or scale, and pressing downward until 3 to 5-lb pressure isobtained.5.2 Mineral Surfacing:5.2.1 To evaluate a granule surface membrane use thefollowing cloth tape evaluation
20、technique:5.2.2 Cloth Tape Evaluation:5.2.3 MaterialCloth tape, 50 mm 2 in. wide, or asagreed upon between the purchaser and seller, to evaluate thegranule surface. Duct tape has proven particularly effective.5.2.3.1 ProcedureApply a 150 mm 6 in. long piece of50 mm 2 in. wide cloth tape to the granu
21、le surface of the roofmembrane being rated. Rub ten times with the index fingertipusing with medium pressure (see Note 1) on the tape to removeall bubbles. Remove the tape from the surface and examine itfor contamination. If the tape gathers loose granules, or othercontaminants, further surface prep
22、aration is necessary. See 6.2.5.3 Ponding Water:5.3.1 Ponding water conditions can cause contaminationwhich is difficult to remove from the membrane. There isusually a high concentration of dust, dirt, and debris in areaswhere water has ponded.6. Preparation of the Surface6.1 Remove contaminants pri
23、or to coating. The followingtreatments offer different methods of preparing the membranesurfaces to receive the coating. The roof must be inspectedprior to performing any of the following surface preparations.If not properly executed, some of these treatments can damagethe membrane.6.2 Surface Prepa
24、ration Techniques:6.2.1 Brooming the membrane surface removes large ob-jects or particulates.6.2.2 Scrubbing with a 457 to 609 mm 18 to 24 in.stiff-bristled broom; must be used with water to significantlyimprove removal of roof contaminants. The surface must thenbe rinsed with clean water until cont
25、aminants have beenremoved.6.2.3 Power WashingLoosely bound surface materialsmust be removed by means of a mechanically driven rotaryscrubbing device that employs a water dispersant. The surfacemust then be rinsed with clean water. Proper operation of theequipment is required to prevent damage to the
26、 membrane (thatis, exposing the reinforcement or disbonding in the lap or seamarea).6.2.4 Cleaning by Pressure WashingThis method of sur-face preparation is capable of removing lightly adhered surfacecontaminations including exudates, loosely bound particulaterelease agents, and aged coating materia
27、l. Proper operation ofthe equipment is required to prevent damage to the membrane(that is, exposing the reinforcement or disbonding in the lap orseam areas).6.3 Application of a primer is not a substitute for properpreparation of a roof membrane surface, the elements of whichare enumerated above. Th
28、e decision to use a primer beforeapplying the coating must not be made without consulting thecoating and sheet material manufacturers requirements for thespecific coating and membrane in use.7. Coating Application Conditions7.1 The roof surface must be continuously evaluated forcontamination during
29、the coating application process. Nosurfaces shall be coated that display evidence of harmful ordeleterious surface conditions.7.2 Application temperatures are as important as surfacepreparation. The coating manufacturers requirements for ap-plication temperatures shall be followed for the ambientcon
30、ditions encountered.8. Keywords8.1 adhesion; application; cloth tape evaluation; coating;evaluation; surface conditions; white cloth evaluationD7120/D7120M 102ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stand
31、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
32、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
33、 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 Cons
34、hohocken, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D7120/D7120M 103
