Designation:E2121−13StandardPracticeforInstallingRadonMitigationSystemsinExistingLow-RiseResidentialBuildings1ThisstandardisissuedunderthefixeddesignationE2121;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticedescribesmethodsforreducingradonentryintoexistingattachedanddetachedresidentialbuildingsthreestoriesorlessinheight.Thispracticeisintendedforusebytrained,certifiedorlicensed,orboth,orotherwisequalifiedindividuals.1.2Thesemethodsarebasedonradonmitigationtechniquesthathavebeeneffectiveinreducingradonlevelsinawiderangeofresidentialbuildingsandsoilconditions.ThesefanpoweredmitigationmethodsarelistedinAppendixX1.Moredetailedinformationiscontainedinreferencescitedthroughoutthispractice.1.3Thispracticeisintendedtoprovideradonmitigationcontractorswithauniformsetofpracticesthatwillensureahighdegreeofsafetyandthelikelihoodofsuccessinretrofit-tinglowriseresidentialbuildingswithradonmitigationsystems.1.4Themethodsdescribedinthispracticeapplytocur-rentlyoccupiedorformerlyoccupiedresidentialbuildings,includingbuildingsconvertedorbeingconvertedtoresidentialuse,aswellasresidentialbuildingschangedorbeingchangedbyaddition(s)oralteration(s),orboth.Theradonreductionactivitiesperformedonnewdwellings,whileunderconstruction,beforeoccupancy,andforuptooneyearafteroccupancy,arecoveredbyGuideE1465.1.5Thispracticealsoisintendedasamodelsetofpractices,whichcanbeadoptedormodifiedbystateandlocaljurisdictions,tofulfillobjectivesoftheirspecificradoncon-tractorcertificationorlicensureprograms.Radonmitigationperformedinaccordancewiththispracticeisconsideredordinaryrepair.1.6Themethodsaddressedinthispracticeincludethefollowingcategoriesofcontractoractivity:generalpractices,buildinginvestigation,systemsdesign,systemsinstallation,materials,monitorsandlabeling,post-mitiga...
