Copyright © 2003 by SSPC: The Society for Protective Coatings

INDUSTRIAL FLOORING INSTALLATION CHALLENGES

James C. Ziegler, ArmorSeal Product ManagerSherwin Williams

Cincinnati, Ohio, USA

Abstract: Specifier's and contractors notonly need to properly evaluate thesubstrate, make proper systemrecommendations and pay attention todetails during the installation, but theymust also have an understanding ofpotential problems and their causes toaid in the successful installation of heavyduty floor coatings and systems.Understanding these issues minimizesproblems and facilitates a successfulinstallation.

Introduction

Heavy duty flooring systems andcoatings can produce an aestheticallypleasing, chemical, wear resistant barrierthat protects the concrete substrates.Concrete floors can be expensive toreplace or maintain if proper care is nottaken to protect them.

Even though concrete can be a verystrong, hard substrate, unprotectedconcrete is subject to deterioration.Concrete is very porous and can besubjected to chemical attack andphysical abuse. Coatings and surfacingsare used to protect concrete, improveappearance and provide ease ofmaintenance.

Seamless floors are manufactured “inplace”. The chemical reaction of thepolymeric materials must be controlledfor successful installation. Failures andchallenges can occur prior to, during or

after the installation. Many of theseproblems can be prevented.When applying coatings and heavy dutyflooring systems, it is important that thecontractor strictly adhere to theapplication requirements for eachproduct. Deviations from themanufacturer’s instructions and job sitespecifications may result in less thananticipated results. Avoiding theseissues and preventing problems is thebasis of an expert flooring contractor.

Substrate Evaluation

The first critical step in avoidingflooring problems is the evaluation ofthe substrate. Concrete, the primarysubstrate on which seamless flooringsystems are applied, is porous. Itbreathes and absorbs liquids whenexposed to the environment. This canpresent a problem both during and afterthe installation of a non-permeable fluidapplied flooring system.

During the substrate evaluation process,responsible parties must determinewhether an effective vapor barrier existsbelow the slab, what potentialcontaminants are in the concrete and theoverall soundness of the concrete,including joint and crack movement.

The effects of moisture vapor emissionsfrom the slab must be thoroughlyevaluated. Remove contaminants fromthe substrate prior to the installation.Mechanical surface preparation may

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remove some of the surfacecontamination, but chemicals and oilsthat penetrate the concrete substrate alsomust be removed or neutralized. Weakconcrete must be replaced and spallsmust be repaired with an appropriatemortar or compatible material to speedthe repair and recoat times.

The foundation of any coating system issurface preparation. The purpose ofsurface preparation is to remove allcontaminants such as concrete laitance,existing coatings, hardeners, sealers andcuring compounds that can interfere withadhesion. Surface preparation alsodevelops a surface profile to promotemechanical adhesion.

Although there are many methods ofsurface preparation available, shotblasting is normally the preferredmethod.

System Recommendation

No two flooring projects are ever thesame and never as simple as they mayfirst appear. Many contractors are askedto make product and systemrecommendations. Representatives fromthe manufacture may assist in makingthese recommendations.

Many factors need to be consideredwhen making any recommendations:

� Shut-down time� VOC’s and odor tolerance� Chemical resistance� Wear and impact resistance� Longevity of the system� Thermal resistance� Slip resistance� Cleanabilty� Light reflectivity� Installation conditions such as

temperature, humidity etc.

Problem Recognition, Causes,Prevention and Remediation

Contractors come across challengeseveryday when applying industrialcoatings and industrial flooring systems.Recognizing problems, causes,prevention and remediation is crucial forsuccessful application.

Bubbles

Bubbles may appear as small as apinhead or greater. They may appearthroughout the entire coating or inclusters. (Figure 1)

FIGURE 1, Bubbles

Cause 1:Air is entrained in the resin while mixingtoo aggressively, improper mixing speedand/or improper mixing equipment.

Prevention:Use the proper mixing equipment formixing industrial coatings, a variablespeed drill at about 300-500 rpm with anappropriate mixing paddle such as a JiffyMixer

Cause 2:Improper application techniques ofmaterials by creating bubbles with theroller or squeegee.

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Prevention:Always use the manufacturer’srecommended equipment. When using100% solids material, spread with asqueegee, back roll with a high quality,lint-free, medium nap roller and use aspike or spiney roller to improve airrelease.

Cause 3:Excessive heat will cause coatings andflooring systems to cure too quickly.Normal air in the coating cannot escape.Thus becoming entrapped and creatingbubbles.

Prevention:Try to avoid elevated temperatures.Monitor the environmental conditions,air, substrate temperatures and humidity.Condition materials for several hoursprior to application.

Cause 4:Direct sunlight will cause similarproblems as excessive heat. Thesunlight heats the top of the coating andcures the material from the top. Thisforms a skin, not allowing air to escape,creating bubbles.

Prevention:Cover windows and doorways to preventdirect sunlight exposure to the coatingsprior to, during and throughout the cureperiod.

Remediation:Thoroughly abrade bubbled coating withsandpaper or a floor grinder, thoroughlyvacuum area and solvent wipe with astrong, clean solvent recommended bythe coatings manufacturer. Re-primeand recoat.

Outgassing

Air pockets in porous concrete escapingduring the curing process, trapped in thefilm, creating bubbles. These bubblestypically have a pinhole that penetratesdirectly to the substrate. (Figure 2).

FIGURE 1, Outgassing

Cause:When the air temperature above thesubstrate is warmer than the substratetemperature and the humidity is lower,the air trapped in the pores of theconcrete expands and the air moves outof the concrete creating bubbles.

Prevention:Check temperature and humidityconditions of the air and substrate. If thetemperature is rising, do not applycoating. Wait to apply materials whenthe air temperature is falling. Doublepriming may also be helpful or using awater-based epoxy primer to seal offentrapped air in the concrete.

Remediation:Thoroughly abrade affected coating withsandpaper or a floor grinder andthoroughly vacuum area and solventwipe with a strong, clean solventrecommended by manufacturer. Re-prime using a high build, fast cureprimer. Large craters may be patchedwith a quick set crack filler.

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Poor Intercoat Adhesion

Poor intercoat adhesion occurs when onecoating does not adhere to the previouscured coat. (Figure 3)

FIGURE 3, Poor Intercoat Adhesion.

Cause 1:Improper preparation of the previouscoating.

Prevention:Prior to applying multiple coats ofmaterial, the previous coating must beproperly prepared and free fromcontaminants. These contaminantsinclude dust, dirt, water or amine blush,and all contaminants must be removedprior to coating.

Cause 2:Recoating outside of recoat window.Most coatings have a range of time orrecoat window when a subsequent coatcan be applied without additionalpreparation.

Prevention:Check the manufacturer’s product datasheet for recoat window times. Do notexceed the recoat window. If the recoatwindow has been exceeded, consultmanufacture’s recommended recoatprocedure.

Cause:When coatings are installed attemperatures less than 5°F above dewpoint, moisture may condense on thesurface acting as a bond-breaker andcould cause inter-coat adhesionproblems.

Prevention:Check temperature and humidity ofsubstrate and air to ensure the substratetemperatures are at least 5°F above thedew point.

Remediation:Mechanically remove any poorly bondedcoating. This may be achieved by shotblasting, grinding or sanding. Existingcoating must have a dull surface fromthe mechanical preparation. Vacuumand solvent wipe existing coating toremove any dust, debris or othercontaminants. Reprime and recoataccording to the manufacturer’sinstructions.

Bond Failure at Substrate

Bond failure at the substrate occurswhen the coating or flooring systemdelaminates at the bond line. (Figure 4).

FIGURE 4, Bond Failure at Substrate.

Cause 1:

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Inadequate surface preparation,preventing a good mechanical bond orleaving a surface contaminant, whichacts as a bond breaker.

Prevention:The foundation of any coating orflooring system is the surfacepreparation. The purpose of surfacepreparation is to remove allcontaminants such as concrete laitance,existing coatings, hardeners, sealers andcuring compounds that can interfere withadhesion and develop a surface profile topromote mechanical adhesion.

Disbonding from the substrate at thetermination or at transitions is related tothe installation detail. Traffic edgesrequire a keyed termination.

Remediation:Mechanically remove coating or flooringsystem. The substrate must then beprepared by following manufacturer’srecommend surface preparationguidelines.

Poor Hardness or TackinessAfter sufficient time, material has notdeveloped proper hardness or mayappear tacky on the surface. (Figure 5)

FIGURE 5, Poor Hardness or Tackiness

Cause:

Applying coatings when temperaturesare below recommended minimumrange. When temperatures are below themanufacturer’s recommendation,materials may never completely cure.

Prevention:Strictly adhere to manufacturer’srecommended installation temperatureguidelines. Monitor environmentalconditions and select the correctproducts for the application.

Cause:Improper mixing or measuring ratio.

Prevention:Use proper equipment, accuratelymeasure components and mixingprocedures in accordance with themanufacturer’s installation instructions.Mixing time, equipment, and proceduresare very crucial and should not bedeviated. Do not mix partial units ifusing small kits or different chemistries.

Remediation:Remove any soft spots, contamination ordirt from the surface. This may have tobe scraped away using a floor scraper orhand tools. Once excess material hasbeen removed, solvent wipe to removeany residue. Once removed,mechanically prepare surface and recoat.

Amine Blush or Greasy Film on theSurface.

Amine blush is a normal chemicalreaction between amine-curing agentsand carbon dioxide when in the presenceof moisture forming a carbonate, whichappears as a greasy film on the surface.This is especially true at lowtemperatures and high humidity.(Figure 6)

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FIGURE 6, Amine Blush

Cause:Amines react with carbon dioxide andmoisture to create a greasy, oily film onthe surface.

Prevention:Check environmental conditions andapply materials when the temperature isa minimum 5°F above dew point andrising. Do not use propane heat inclosed environments because they emitCO2.

Remediation:The amine blush or greasy film must beremoved. Solvent wiping prior to theapplication of the next coat is alsoutilized, but it can leave residualcontaminants if not thoroughly cleaned.It is best removed by using a hot waterdetergent scrub and rinse.

Fish-eyesFish-eyes are areas where the coatingpulls away from the surface or previouscoating. (Figure 7).

FIGURE 7, Fish-Eyes

Cause:Contamination on the substrate or coatedsurface are frequently caused by blush,surface oils, animal fats, vegetable oil,grease, silicone or petroleum basedproducts.

Prevention:Prior to application of any coating, thesubstrate must be inspected for anycontaminants including dirt, debris,amine blush or residues.

Remediation:The surface must be thoroughly sandedor abraded to remove the contaminationand to roughen the previous coat. Oncethe surface is mechanically prepared,solvent wipe to remove any dust, dirt orresidual contamination, prior torecoating.

Disbonding in Form of a Blister

Moisture vapor transmission will causeloss of adhesion and blistering. Themoisture in the pores of concrete willmigrate toward the warm, dry air abovethe substrate. (Figure 8).

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FIGURE 8, Disbonding from MoistureVapor Transmission

Cause:Moisture vapor transmission.

Prevention:After surface preparation, the substratemust be tested for moisture vaportransmission with a calcium chloride testkit at “use” conditions. The results mustgenerally be less than 3 pounds ofmoisture per 1000 square feet per 24hours period. The coatings or flooringsystems must also be installed at “use”conditions.

Remediation:The flooring system must be removed.Raising the temperature and increasingthe ventilation prior to retesting mayhelp remove the excess moisture.Treating the surface with a penetratingsilicate, siloxanes, or gel formingpolymers may decrease the permeabilityand inhibit the path of moisture.

Color Shading

Uniform color but different shades ofcolor, sometimes dark or light streaksappear in the film. (Figure 9).

FIGURE 9. Color shading

Cause:Using multiple batch numbers.

Prevention:Check batches while staging the project.If there are multiple batch numbers,“boxing” batches together for uniformlyof color.

Cause:Improper mixing.

Prevention:Always use proper mixing equipmentwhen mixing industrial coatings andfloor surfacing products. Use a variablespeed drill, Jiffy mixing blade, on lowspeed. Premix material prior to addingmultiple components together. Oncepremixed, slowly pour componentstogether and mix for 2 to 3 minutes anduntil uniform. Carefully followmanufacturer’s instructions.

Remediation:Thoroughly abrade coating withsandpaper or a floor grinder.Thoroughly vacuum area and solventwipe with a strong, clean solvent.Reprime and recoat.

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Summary

Heavy duty flooring systems andindustrial coatings require surfaceevaluation, accurate system selectionand professional installation to preventexpensive problems. Taking the timeand effort to understand the potentialproblems and implementing the correctmeasures to prevent them is the hallmarkof a successful professional flooringinstaller.

Bubbles: Air bubbles may appear as small as a pinhead or greater. They may appearthroughout the entire coating or in clusters.Cause Prevention Remediation-Air entrainment in theresins during mixing and orapplication

-Use manufacture’srecommended equipmentfor mixing and application.When using 100% solidsmaterial, spread with asqueegee, back roll with ahigh quality, lint-free,medium nap roller and use aspike or spiney roller toimprove air release.

-Excessive heat - Try to avoid elevatedtemperatures. Monitor theenvironmental conditions,air, substrate temperaturesand humidity. Conditionmaterials for several hoursprior to application.

-Direct sunlight - Cover windows anddoorways to prevent directsunlight exposure to thecoatings prior to, during andthrough the cure period.

Thoroughly abrade bubbledcoating with sandpaper or afloor grinder, thoroughlyvacuum area and solventwipe with a strong, cleansolvent recommended bymanufacturer. Reprime andrecoat.

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Outgassing: Air pockets in porous concrete escaping during the curing process, trappedin the coating crating bubbles.Cause Prevention Remediation- When the air above thesubstrate is warmer than thesubstrate temperature andthe humidity is lower, theair trapped in the pores ofthe concrete expands andthe air moves out of theconcrete creating bubbles.

-Check temperature andhumidity conditions of theair and substrate. If thetemperature is rising do notapply coating. Wait toapply materials whentemperature is falling.Double priming may also behelpful or use a water-basedepoxy primer to seal offtrapped air in the concrete.

Thoroughly abrade bubbledcoating with sandpaper or afloor grinder, thoroughlyvacuum area and solventwipe with a strong, cleansolvent recommended bymanufacturer. Reprimeusing a high build, fast cureprimer. Large craters maybe patched with quick setcrack filler.

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Poor Intercoat Adhesion: Poor intercoat adhesion is when one coating application doesnot adhere to the previous cured coating.Cause Prevention Remediation-Improperly preparedprevious coating

-Prior to applying multiplecoats of material, theprevious coating must beproperly prepared and freefrom contaminants. Thesecontaminants include dust,dirt, water or amine blush,which must be removedprior to coating.

-Recoating outside of recoatwindow. Most coatingshave a range of time when asubsequent coat can beapplied without additionalpreparation.

-Check manufacture’sproduct data sheet for recoatwindow times. Do notexceed recoat window. Ifthe recoat window has beenexceeded, consultmanufacture’srecommended recoatprocedure.

Mechanically remove anypoorly bonded coating.This may be achieved byshot blasting, grinding orsanding. Existing coatingmust have a dull surfacefrom the mechanicalpreparation. Vacuum andsolvent wipe existingcoating to remove any dust,debris or othercontaminants. Reprime andrecoat according tomanufacture’s instructions

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Bond Failure at Substrate: Bond failure at the substrate occurs when the coating orflooring system delaminates at the bond line.Cause Prevention Remediation-Inadequate surfacepreparation preventing agood mechanical bond orleaving a surfacecontaminant, which acts asa bond breaker.

- Remove all contaminantssuch as the concretelaitance, existing coatingshardeners, sealers andcuring compounds that caninterfere with adhesion anddevelop a surface profile topromote mechanicaladhesion.

Mechanically removecoating or flooring system.Then the substrate must beprepared by followingmanufacturer’s recommendsurface preparationguidelines.

Poor Hardness or Tackiness: After sufficient time, material has not developed properhardness or be tacky on the surface.Cause Prevention Remediation-Applying coatings whentemperatures are belowrecommended minimumrange. When temperaturesare below manufacture’srecommendation, materialsmay never reach completecure.

-Use proper equipment;accurately measurecomponents and mixingprocedures in accordancewith manufacture’sinstallation instructions.

Remove any soft spots,contamination or dirt fromthe surface. After excessmaterial has been removed,solvent wipe to remove anyresidue. Once removed,mechanically preparesurface and recoat.

Amine Blush: Amine blush is a normal chemical reaction between amine-curing agentsand carbon dioxide when in the presence of moisture form a carbonate, which appears asa greasy film on the surface.Cause Prevention RemediationAmines react with carbondioxide and moisture tocreate a greasy, oily film onthe surface.

-Check environmentalconditions and applymaterials when thetemperature is a minimum5°F about dew point. Donot use propane heat inclosed environments.

The amine blush or greasyfilm must be removed. It isbest removed by using a hotwater detergent scrub andrinse. Solvent wiping priorto the application of thenext coat is also utilized,but it can leave residualcontaminants if notthoroughly cleaned.

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Fish Eyes: Fish-eyes are areas where the coating pulls away from the surface or previouscoating.Cause Preventions Remediation-Contamination on thesubstrate or coated surfaceare frequently caused byblush, surface oils, animalfats, vegetable oil, grease,silicone and petroleumbased products.

-Prior to apply any coatingthe substrate must beinspected for anycontaminants including dirt,debris, amine blush orresidues.

The surface must bethoroughly sanded orabraded to remove thecontamination and toroughen the previous coat.Once the surface ismechanically prepared, asolvent wipe to remove anydust, dirt or residualcontamination must be doneprior to recoating.

Disbonding in form of a blister: Moisture vapor transmission will cause loss ofadhesion and blistering. The moisture in the pours of concrete will migrate toward thewarm, dry air above the substrate.Cause Prevention Remediation-Moisture vaportransmission

-After surface preparation,the substrate must be testedfor moisture vaportransmission with a calciumchloride test kits at “use”conditions. The resultsmust generally be less than3 pounds of moisture per1000 square feet per 24hours period. The coatingsor flooring systems mustalso be installed at “use”conditions.

The flooring system mustbe removed. Raising thetemperature and increasingthe ventilation prior toretesting may help removethe excess moisture.Treating the surface with apenetrating silicate,siloxanes, or gel formingpolymers may decrease thepermeability and inhibit thepath of moisture.

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Color shading: Difference in shades of color.Cause Prevention Remediation-Using multiple lotnumbers.

-Check batches whilestaging the project. If thereare multiple batch numbers,“boxing” batches togetherfor uniform color.

-Improper mixing. - Always use proper mixingequipment when mixingindustrial coatings and floorsurfacing products. Use avariable speed drill, Jiffymixing blade, on low speed.Premix material prior toadding multiple componentstogether. Once premixed,slowly pour componentstogether and mix for 2 to 3minutes and until uniform.Carefully followmanufacture’s instructions.

Thoroughly abrade coatingwith sandpaper or a floorgrinder, thoroughly vacuumarea and solvent wipe witha strong, clean solvent.Reprime and recoat.

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