1、Designation: D7120/D7120M 10 (Reapproved 2017)Standard 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 cas
2、e 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.1. Scope1.1 This guide covers the procedures for evaluating andpreparing non-aggregate surfaced membran
3、es for the applica-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 standar
4、d. 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, associ
5、ated 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. Terminology2.1 Definitions:2.1.1 adequate drainage, nthe drainage condition inwhich consideration h
6、as been made for all 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 contam
7、inant, nany of sev-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
8、, and chemicals from 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.
9、 Exudates inhibitcoating 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 growt
10、hs, usually algae 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 sticki
11、ng to itself while 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 s
12、urface coating.3.2 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
13、failure of liquidapplied 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 b
14、e requiredto prepare 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 Jan. 1, 2017. Published
15、January 2017. Originallyapproved in 2010. Last previous edition approved in 2010 as D7120/D7120M 10.DOI: 10.1520/D7120_D7120M-10R17.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance
16、 with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15. Roof Surface Evaluation5.1 The roo
17、f membrane surface evaluation shall be con-ducted prior to the application of a surface coating. Surfaceevaluation will assist 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 adhes
18、ion of thecoating.5.1.2 Perform a “cloth tape evaluation” to determine thepresence and type of contaminants on the roof surface 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.
19、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 MaterialWhite 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
20、 the surface being evaluated. Determinethe presence or absence of contamination using this evaluationtechnique. If no contamination 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
21、pressure isobtained.5.2 Mineral Surfacing:5.2.1 To evaluate a granule surface membrane use thefollowing cloth tape evaluation 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
22、 has proven particularly effective.5.2.3.1 ProcedureApply a 150 mm 6 in. long piece of 50mm 2 in. wide cloth tape to the granule 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 fr
23、om the surface and examine itfor contamination. If the tape gathers loose granules, or othercontaminants, further surface preparation 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 c
24、oncentration of dust, dirt, and debris in areaswhere water has ponded.6. Preparation of the Surface6.1 Remove contaminants prior to coating. The followingtreatments offer different methods of preparing the membranesurfaces to receive the coating. The roof must be inspectedprior to performing any of
25、the following surface preparations.If not properly executed, some of these treatments can damagethe membrane.6.2 Surface Preparation 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 us
26、ed with water to significantlyimprove removal of roof contaminants. The surface must thenbe rinsed with clean water until contaminants have beenremoved.6.2.3 Power WashingLoosely bound surface materialsmust be removed by means of a mechanically driven rotaryscrubbing device that employs a water disp
27、ersant. The surfacemust then be rinsed with clean water. Proper operation of theequipment is required to prevent damage to the 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 removi
28、ng lightly adhered surfacecontaminations including exudates, loosely bound particulaterelease agents, and aged coating material. 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 o
29、f a primer is not a substitute for properpreparation of a roof membrane surface, the elements of whichare enumerated above. The decision to use a primer beforeapplying the coating must not be made without consulting thecoating and sheet material manufacturers requirements for thespecific coating and
30、 membrane in use.7. Coating Application Conditions7.1 The roof surface must be continuously evaluated forcontamination during the coating application process. Nosurfaces shall be coated that display evidence of harmful ordeleterious surface conditions.7.2 Application temperatures are as important as
31、 surfacepreparation. The coating manufacturers requirements for ap-plication temperatures shall be followed for the ambientconditions encountered.8. Keywords8.1 adhesion; application; cloth tape evaluation; coating;evaluation; surface conditions; white cloth evaluationD7120/D7120M 10 (2017)2ASTM Int
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34、ould be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible 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 St
35、andards, 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 10 (2017)3
