ASTM_D_7120_-_D_7120M_-_10_2022.pdf

Designation:D7120/D7120M10(Reapproved 2022)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 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.1.Scope1.1 This guide covers the procedures for evaluating andpreparing non-aggregate surfaced membranes 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 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 nonconformancewith 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Terminology2.1 Definitions:2.1.1 adequate drainage,nthe drainage condition inwhich consideration has 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 adverselyaffect the adhesion of a coating.2.2 Contaminant List:2.2.1 air/water-borne surface contaminant,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,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.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 growths,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 sticking to itself while in the roll.2.2.8 surface oxidate,na barrier film,which forms on thesurface of an unprotected smoothAPPsheet 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 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 liquid-applied coatings.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 Nov.1,2022.Published November 2022.Originallyapproved in 2010.Last previous edition approved in 2017 as D7120/D7120M 10(2017).DOI:10.1520/D7120_D7120M-10R22.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance 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.14.2 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 prepare the surface of an APP modifie