# Preparing a painted Concrete floor for VCT Tile



## FINI (Jun 20, 2010)

Hi, I have a large job to bid on that has a painted concrete floor..Looks like the standard grey color concrete paint that alot of home owners use to make their basement or garage look good. I'm trying to find the best way to prepare this floor to accept the S-515 adhesive with VCT tile. Armstrong recommends using a Trisodium Phosphate mix to strip the paint off. Does anyone have a better idea to get this floor ready? 

Floor sander using the wire blush option?

Thanks


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## opiethetileman (Apr 7, 2005)

How large is the area? If its wide open rent a floor sander and just sanded it down. I use a 7 inch grinder to sand down floors. Very dusty but it gets it smooth and flat. I would also clean the floor with either mineral sprits after its all sanded down. Or TSP solution.


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## griz (Nov 26, 2009)

Not quite sure how TSP will strip paint. Have you tested it for lead or asbestos? Most mfg. I have run across require the floor to be bead blasted for the adhesive warranty. Does the flooring mfg. require a sealer for the warranty? Better check.


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## opiethetileman (Apr 7, 2005)

TSP is for cleaning the slab prior to installing the VCT. The slab will be dirty and needs to be clean for the glue to adhere to it.


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## BKM Resilient (May 2, 2009)

TSP will not "strip off" any paint and I don't think any VCT installed over paint would ever be warrantied. TSP is just for cleaning up the painted surface for another coat of paint or glue in your case. There's no way to know how well the existing paint is bonded to the slab. The reality is that your customer has to either PAY to remove the paint or absolve you of responsibility for the risk of that paint peeling loose. We lay over painted floors fairly frequently so it's not that big of a deal if everyone gets on the same page. 

Assuming the paint is well bonded it's a REALLY bad idea to try chemically "stripping" it off. Anything that dissolves paint will penetrate the concrete pores and leave a residue that will impair a good adhesive or patch bonding to that slab. So IF they want the factory warranty that paint has to come off "mechanically". Usually some paint can be scraped or sanded but just as typically there's large areas that require bead blasting or diamond grinding. 

If you're going to just lay over the paint after getting up any loose areas with scrapers and sanders then the biggest issue is getting it clean for the patch. Virtually any concrete slab will need patching and skim coating for a good VCT job. The glue will bond just fine to a clean painted floor but there's often issues with getting patch to bond. That's because almost all painted floors would have MANY coats of God only knows what kind of sealers, waxes or finishes. Those are your biggest enemy. Lean into the floor sander with the heaviest grit and get it off of there. Once the floor is as clean as you can get it use the right PRIMER for the floor patch you choose to use over that paint. Some primers are for porous substrates and some work only on non-porous. This is a big deal if your area will be exposed to heavy traffic and frequent cleaning. 

VCT will hide a multitude of sins in areas that DONT receive heavy traffic and frequent washing so how critical all my advice is really depends on the type of use this floor needs to withstand.


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## PrecisionFloors (Jan 24, 2006)

OP, listen to BKM when it comes to resilients and you'll be ok. He speaka da truth.


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## opiethetileman (Apr 7, 2005)

I never said it would clean it or strip. I have used it to neuteralize before i put a primor down and such before. Not for VCT I havent done that type in years. I know they make a chemical to strip it the paint off the slabthat is. But ya think buy now they would make a glue that would grab to anything.


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## PrestigeR&D (Jan 6, 2010)

*Opie,,,*

They do,,,,,,but it is only as good as what it is bonding to. If the paint is going to blyster,peel, or loose it's bond with the concrete for various reasons- well,,,you can't blame the product . 

Brian


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## cretebuster (Jun 27, 2010)

FINI said:


> Hi, I have a large job to bid on that has a painted concrete floor..Looks like the standard grey color concrete paint that alot of home owners use to make their basement or garage look good. I'm trying to find the best way to prepare this floor to accept the S-515 adhesive with VCT tile. Armstrong recommends using a Trisodium Phosphate mix to strip the paint off. Does anyone have a better idea to get this floor ready?
> 
> Floor sander using the wire blush option?
> 
> Thanks


I think the sure way of removing the paint is to get a diamond cup wheel on a 7 inch grinder or you can rent a set up with a diamond cup wheel from home depot that will suck up the dust as you go and then clean it off with a muratic acid solution,


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## RhodesHardwood (Jun 28, 2010)

Your options are to acid etch, or diamond grind the entire floor


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## BKM Resilient (May 2, 2009)

pspman222 said:


> float it?


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Flooring installers use "float" in a couple different ways. Some guys use the term float to refer to a heavy coat of floor patch because we then use our finishing trowels in a manner very similar to the way cement finishers use theirs when they're "floating" the concrete. 

More recently "floating" floors of all kinds have come into popularity. Floating the engineered or laminated woods has been around for a while but these resilient Konecto-type floating floors seem to be really catching on in residential applications. 

I don't recommend the floating resilient floors for any commercial use. I expect over time they will be seen as another foolish fad. Who know? 

If by "float it" you meant throw a skimcoat of floor patch over the paint that's generally a bad idea. Where the paint is smooth and well bonded and the objective is COST SAVINGS from bead blasting or grinding it's really no problem to spread clear thin spread adhesive and lay VCT. Problems are much more frequent where the painted floor is in need of smoothing and leveling. Paint isn't a good surface for patch to bond to. Certainly you can and will use a liquid latex additive to prime the floor but the key is really getting all the old grease, slime and wax off of there so you're actually bonding to paint and not whatever else may have been smeared over it. 

So I would want to see as little patch over the paint as possible. Were the floor really in horrible shape then it's a bad idea to leave any paint whatsoever. At that point you need to get the diamond grinders or bead blasters and remove all trace of it. That's the right way to do it. The only reason to ever scab over existing paint is to cheap out and save a few nickels. That's only a good idea if you're not heading for total failure or big hassles down the road.


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