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How do I install Porcelain Tile over Painted Concrete?
QUESTION
Installing Porcelain Tile over Painted Concrete - I would like to place porcelain tile over a painted concrete slab. How should I do this?ANSWER
ANSWER - It is possible to bond porcelain tile to a painted surface, but it isn't recommended because the overall tile attachment is limited to the strength of the bond of the paint to the concrete. If the paint comes loose, so does the tile. You should either strip or bead blast the concrete and thoroughly clean it. Water should readily absorb in the concrete as an indication that it is suitable for bonding the tile to it.If you choose to try to bond the tile to the paint, then you need determine what type of paint it is. An epoxy based paint requires an epoxy adhesive to bond to it. A latex based thin-set adhesive should be used over the latex based paint. Only use epoxy and latex thin-set products that state they can be used for bonding tile to paint. The painted surface has to be cleaned properly to ensure an adequate bond. If the paint is not well attached then as the thin-set adhesive dries and shrinks, it might pull the paint loose. Beware!!!! Gook Luck!
20 thoughts on “How do I install Porcelain Tile over Painted Concrete?”
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I contract to a large volume builder the painters go in first then we tile my question is has the builder or the builders supervisors got a care of duty to me the tiler to make sure all the paint is off the slab prior to tiling or the painter for that matter they spray ceilings and in most cases the walls as well now I being held reasonable when the floor tiles have lifted can some one help me out
Your contract should state that the GC is to provide you with a concrete substrate that is not contaminated with paint, oil, curing compounds or any other contaminate that can interfere with the tile installation.
ANSI A108.02 standard says that the tile installer is to inspect the tile , the substrate and the surrounding conditions, and if any condition exists that will prevent you from properly installing the tile then you must stop your work and notify the GC or client in writing of the problem, and do not continue the work until the corrections have been made.
If you install over a substrate that has paint on it and you don’t clean it up, then it becomes your problem, because you should not have installed over it.
We have used a grinder to (try) to remove paint from our concrete floor before laying tile. We’re finding it hard to get it 100% off. And it’s really frustrating. There are random spots where the paint is light but still present. Does it have to be 100% gone, or is there any level of “close enough”? Like if let’s say 90% of the area of any given tile will be paint free underneath with only 10% paint in random spots, would that be relatively good?
I’m not usually the type to give up but… this is really beating us up.
Warranty wise, you need to follow the manufacturer’s directions. It is always better to remove all of the paint and contaminates and to grind the floor to open up the pores of the concrete. You can use a cup grinder to grind it off.
If you are using a good adhesive it might bond to the painted surface, but the attachment then is only as good as the paint is attached to the concrete. So there is a risk that sometime in the future it might release.
Personally I would follow the thin-set manufacturer’s directions and remove all of the paint by scarifying. If you have the right tools it will go fast and will be easier than trying to scrape it off. You can also use paint strippers to remove the paint, but then you have to clean the floor to remove any residuals.
Sunroom originally was the patio that owners then framed. When I brought the house, the floor was painted and rock was mixed into concrete. Is it possible to lay porcelain tile over the uneven sunroom floor if we remove paint?
As long as there are not structural cracks in the concrete floor you can install porcelain tile over it. You need to prepare by removing the paint and scarifying the surface to open up the pores of the concrete. You want water to readily absorb into it. If you use a stripper to remove the paint be sure to flush it thoroughly to remove any residuals.
After you have a clean concrete slab you can grind down high spots and you can flatten or level the surface by using a patching mortar for tile installations. Then you can adhere the tile to it. If there is an indication that there is high moisture or shrinkage cracks in the slab install a waterproof/crack isolation membrane first.
I have a covered, concrete patio entry way I have painted every other year for the last six years and now I want to do a porcelain tile overlay. The outer portion of the slab was added onto and is exposed to the outdoor elements. The paint chips on this newer portion of the slab so I now i need to strip this portion. However, the original portion that is covered was installed in the 60’s. The condition is porous and it was never finely finished with a trowel. There is very little chipping and some fading on this portion. Do I need to be thinking about stripping this portion has well? It seems as though that the paint is being absorbed into the slab because of the final condition it was left in.
You should strip all of the paint off or grind it off with a vacuum shroud. Even if you do strip it, you should grind the slab with a cup grinder to open up the pores and remove any contaminates. Then power wash it to be complete clean and saturated surface dry (damp not wet).
Make sure you don’t have any cracks in the concrete particularly at that transition from the old to new slab. If you do have shrinkage cracks (no vertical displacement) then you can treat the entire surface with a crack isolation membrane that is also a waterproof membrane.
Make sure you have an adequate slope to drain so water doesn’t puddle. The concrete and the membrane surface should slope 1/4″ per foot. You might have to apply a bonded mortar over the surface to create the slope if you need it.
I’d like to install panel stones to some areas at the outside front wall. I was thinking instead of removing the paint from the stucco , could be possible to attach 1/4 inch cement board with blue (concrete) screws and then use a regular thin set for the panel stones? I don’t have big areas, I have one area: 10′ W x 3′ H and another one: 11′ H x 3′ W
Thank you,
Depends on what you mean by stone panels. If you are thinking large slabs of stone that is 3/4″ (2 cm) or 1-3/16″ (3 cm) you might need to mechanically anchor those.
If you are thinking maybe 2’x2’x1/2″ stones then you can adhere them to the wall.
If you have a stucco wall that is a weak cementitious material so with or without paint you can’t attach to it. Question is what is the stucco attached to? concrete block? or plaster brown coat over framing? If that is the case you can grind off the stucco with a disk grinder that will go quick with the right grinder with a 7″ diameter disk.
You could screw 1/4″ backer board to the wall to avoid the grinding off of the stucco assuming it is sturdy and without excessive deflection. You need to screw into the concrete block or into wood or metal studs. You still want to use a thin-set board on the back of the backer board when you attach it so it is fully supported and so you can shim and plumb it.
Of course you need to use the correct adhesives and install it correctly per industry standards.
13X13 porcelain tile the back being a shallow mesh look 1″X1″ grid pattern. Going over bathroom floor. Has oil-based overspray from 1987 along cabinet bases and door jambs out about 5-6″. It does not flake. I have Mapei Ultraflor Plus. I doubt water will soak past the enamel. I can wirebrush if necessary. What should I do?
It is never recommended to bond over paint because someday when the paint degrades the tile will become loose.
The polymer modified thin-set mortars might bond to a latex paint, but not an oil based paint. Mapei Ultrafor Plus data sheet says to use their Keraply Latex admix in lieu of water when going over impervious surfaces; not that they would endorse going over an oil based paint…
What you should do is scarify the paint off the floor. Use a cup grinder pad or whatever to remove it. Make sure that the concrete floor readily absorbs moisture.
Hi
I have a concrete subfloor that has mastic residue from sheet vinyl but the floor is mostly smooth. Would liquid Red Gaurd with a modified thinset be ok to install once the floor is prepared or would an uncoupling product be better? What is the best way to find out if a prospective contractor is knowledgeable?
There are some polymer modified thin-set mortars where they say you can scrap all of the excess mastic off of the concrete slab and then adhere to it.
There are also strippers that will emulsify the mastic and you can scrape it up, but it is a messy process and can still bleed into the concrete.
If it were me, I would scrape it clean and then get a cup grinder and grind it down to expose the concrete so it readily absorbs water and bond to it. Or apply the Redgard first and bond to it.
I’m not a fan of uncoupling membranes unless you have a really badly cracked slab. They tend to give a hollow sound and raises the height of the floor. I would rather grind the floor and patch it to make it flat within 1/8″ in 10′ and within 1/16″ within 24″.
Most installers have not formal installation training and are not fully aware of the industry standards. They may, or may not, do good work. You have to the quality control person making sure they follow manufacturer’s directions and industry standards. If they have taken the UofCTS Tile Installer ITS course then that is a plus or if they are a certified tile installer through CTEF that is plus.
My house has stained concrete floors and I want to put tile down. I was told it would be easier to sale the house and buy another because the sanding and stripping is going to be extremely messy. Any ideas?
You should be able to easily grind the slab down to remove the stain on the surface and open up the pores of the concrete. To make sure you have prepared it properly, apply drops of water over the area and if the water readily absorbs into the concrete that should be an indication that there are not contaminates that would act as a bond breaker. Make sure you clean the concrete well after grinding and before you install the tile.
I have a concrete slab that is level but has an adhesive like substance left behind from pulling up old carpet . I will be installing 6″x36″ porcelain planks. Do I have to use the quick set if its already leveled ? Also there’s not much sticky substance left behind .Is it safe to skip the quickcset step and go straight to grouting the tiles as is ?
For a 6×26 inch tile the surface of the concrete has to be flat and not exceed industry tolerance of not being out of plane more than 1/8″ in 10 feet or more than 1/16″ in 24″. Otherwise you are more likely going to have tile lippage issues.
If there is a carpet glue on the concrete it should be removed. It is best to scarify it off with a dustless grinder.
I assume when you say quick set you mean a thinset mortar adhesive. You have to use an ANSI A118.4 or AN A118.15 thinset mortar to bond the porcelain tile to the concrete substrate. Grouting is done after the tile is set and the thinset has cured for at least 24 hours.
OK I have a kitchen that originally had Parquet wood floor squares held down with black cut back adhesive on concrete slab. Thirty years ago we took that up and scraped the floors with a power scraper. We then per vinyl flooring companies instruction rolled the floor with kilz to prevent bleed through. Ten years later that vinyl was removed, floor re-scraped and and Kilz reapplied . We then installed 14×14 ceramic tiles set with TEC polymer fortified thin set and grout. That floor was in for 20 yrs or so and no cracking, loose grout or any issues. We now wish to install LVP plank flooring however there are low spots and higher spots that exceed the manufactures recommendations for the flooring and I wish to utilize a self leveling product to flatten the floor. When I took up the tiles in about 60 % of the area the Kilz stayed bonded to the thinset and the separation occurred between the cutback and the Kilz and on the remainder the separation was between the Kilz and the thinset. My question is: Is there a primer that I can utilize that will allow floor leveler products to adhere to this properly. The TEC thinset worked great for 20 yrs holding the tile and floating the low spots I just don’t know if the self leveling products have that level of adhesion to the Kilz (or cutback if floor wasn’t recoated). I really don’t want the mess of grinding or scarifying the concrete.
It is always best to remove all materials over the concrete, which can be contaminates and interfere with the attachment of new materials. Even if you can bond to left over residuals, their bond strength is likely less than what you can achieve if you bond directly to the properly prepared concrete.
What you should do is scrape and grind off all residuals from other installations down to the concrete surface. The concrete surface should clean and have a profile of CSP 2 or 3 with a little texture to help bond better to the concrete. The concrete should readily absorb moisture to further ensure you get a good bond.
You should use a cementitious self-leveling that isn’t sensitive to moisture. The manufacturer’s directions normally require that you apply their primer first to the concrete to further ensure of a good attachment.
Although the industry lately is advertising their LVP products as waterproof, they don’t make the installation waterproof. Technically their product maybe waterproof, but the manufacturer doesn’t say you will have a waterproof floor.
If you want a long lasting and durable floor that is waterproof, then install a porcelain wood plank tile over a liquid applied waterproof membrane.