Installation Guide

• Useundilutedovermoisture-stable,exterior-grade
plywood.
• Useundilutedoverdense,nonabsorbentsurfaces,
such as epoxy moisture barriers, floor-covering
adhesive residue, and properly prepared ceramic tile
and VCT.
• Dilutetheproductforapplicationoverabsorbent,
porous substrates at a ratio of 1:1 to 2:1 (water to
primer).
SUITABLE SUBSTRATES
• Properlypreparedandbondedtile,stoneandVCT
• Properlypreparedandinstalled100%-solidsepoxy
moisture barriers
• Epoxycementterrazoandpouredepoxyflooring
• Cementbackerunits(CBUs)
• Substrateswithtracesofwell-adhered,water-resistant
glue(cutbackadhesive,floor-coveringadhesiveor
polyurethane adhesive)
• Dimensionallystableexterior-gradeplywood
• Properlypreparedsoundandstableconcrete
substrates, whether smooth and nonabsorbent
or profiled and absorbent
• Useovergypsum-basedSLUsthatarefreeofgypsum
dust before application of cementitious or gypsum-
based SLUs.
ConsultMAPEI’sTechnicalServicesDepartmentfor
installation recommendations regarding any substrates
and conditions not listed.
SURFACE PREPARATION
• Allsubstratesmustbeinterior,structurallysound,dry,
solid and stable.
• Mechanicallyprepareexistingceramic,quarryand
porcelaintile,aswellascementterrazzo.
• Thoroughlycleanallsurfacesofanysubstancethat
could interfere with the bond of the installation material,
including dirt, paint, tar, asphalt, wax, oil, grease, latex
compounds, sealers, curing compounds, form release
agents, laitance, loose toppings, foreign substances,
and poorly bonded adhesive residues.
• Donotacid-etchsurfacesbeforeapplyingPrimer T.
• WhenapplyingMAPEIunderlaymentstoplywood
flooringororientedstrandboard(OSB),theinstallation
specifics (finished flooring, load, use and/or deflection)
mayrequiretheuseofMAPEI’sMapelath
™
or diamond
mesh(meetingtherequirementsofASTMC847)on
top of the primed surface before application of the
underlayment. In all cases, one can anticipate better
performancewhenutilizinglath,particularlyover
OSB.RefertoMapelath’scurrentTechnicalDataSheet
forinstallationinstructions.Differentialorexcessive
movement within a plywood substrate may lead to
hairlinecracksatplywoodjoints.
MIXING
Note:Chooseallappropriatesafetyequipmentbeforeuse.
RefertotheSafetyDataSheetformoreinformation.
1a. Over nonabsorbent surfaces: Apply Primer T undiluted.
(Addnowater;nomixingisrequired.)
1b. Over porous, absorbent surfaces (typically absorbent,
profiled concrete substrates):DilutePrimer T with water
at a ratio of 1:1 to 2:1 (water to primer). Mix with water
in a separate clean container with a low-speed mixer
andpaddletoahomogenousconsistency.Donotmix
at high speeds, which may cause product foaming.
1c. Over gypsum substrates:Diluteataratioof2:1(water
to primer). Mix as indicated in Step 1b and apply two
coatsifrequiredbyvisualinspection.Ensurethatthe
gypsum substrate is sound and free of gypsum dust.
PRODUCT APPLICATION
Note: Read all installation instructions thoroughly before
installation.
1. Applytheproductwitha3/8"(10mm)naproller.Ensure
that the surface receives a complete, thin film of product.
2a. Nonabsorbent substrates and woodrequireonlyone
coat of undiluted Primer T.
2b. Absorbent and gypsum substratesmayrequiremore
than one coat of diluted Primer T to seal off the substrate
and prevent substrate outgassing.
3. Theunderlaymentcantypicallybeappliedwithin2to
5hours(seethe“ShelfLifeandApplicationProperties”
table).Dryingtimeswillvarydependingontheporosity
of the surface, temperature and humidity. The maximum
waittimefrominitialapplicationis24hours.
4. IfthedriedPrimer T remains uncovered for more than
24hours,re-applyasecond,undilutedcoatandinstall
the underlayment within the correct application window
(seethe“ShelfLifeandApplicationProperties”table).
If the application window is missed again, remove the
primer mechanically and start the installation on the
clean substrate.
CLEANUP
• Cleanequipmentimmediatelywithwater.Mineralspirits
may be used to remove primer that has dried on tools.
Pri
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Pri
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