Can epoxies be applied over tiles?

One common question you hear in the epoxy field no matter where you come from is – “can I coat over tiles?”

Tiles were, and still are, a popular flooring choice. Their durability is typically great and the right tile can really look fantastic. However, chipping/cracking and slip resistance are not their strong points and grout lines are probably their biggest weakness in a number of ways.

Because of this, some people want a change from their existing tiled floor, however they realise that to remove the tiles is typically a big job that can be costly and time consuming. There can also be other reasons for not wanting to remove the tiles, eg having to raise the floor level again by 10 – 15mm afterwards. Many of these people see a decorative seamless floor and think, “wouldn’t it be great if I could just apply it over the top of the tiles!?”

So back to the question, can you overcoat tiles?…

Image showing the grout line ghosting underneath the decorative floor.

Image showing the grout line ghosting underneath the decorative floor.

The fundamental answer is yes, but there are some conditions and additional thoughts you should consider before jumping in.

Here are the questions I ask when someone comes to me and wants to overcoat tiles -

Are the tiles glazed?

Yes - then you need to remove the glaze. You can look to micro-etch with an acid-based etcher, but in my experience the adhesion can be inconsistent with this kind of preparation. Hence, I suggest mechanically grinding to remove the glaze. It’s always hard to achieve 100% removal, but that is not always necessary to achieve strong levels of adhesion.

No – is there a sealer on the tiles? Lots of terracotta tiles aren’t glazed but tilers can apply a sealer to prevent the tiles from looking dirty or showing a spill. If the tile is sealed then you are back to grinding as you are not likely to get good mechanical penetration of the resins into the tile. A lot of sealers also have hydrophobic properties whereby they repel water or any other product trying to penetrate the surface, which obviously makes the task of gaining strong adhesion even more difficult. If the tiles are not glazed and not sealed, then you can clean them (and grout lines) and look to overcoat.

Are the tiles level/flat?

Yes – then look to clean and overcoat.

No – then you may choose to grind flat or apply a levelling compound. The levelling compound could be cementitious or epoxy based.

Are the tiles “drummy” or cracked? Has the grout line cracked?

You need to inspect and test every tile to figure out if it is well bonded. Tapping it with a screwdriver handle or a small hammer can usually reveal if the tiles are loose. Any “drummy” tiles should be removed and the space filled with a levelling product. Cracked grout lines may also need to be removed and a levelling compound applied in its place to fill in the gaps/re-level.

With those substrate-related questions out of the way, here are some other things you need to consider -

What finish are you after – smooth or textured?

If you want a smooth finish then levelling will need to be of a high standard. You can’t have any grout line “ghosting” (ie showing through – see picture above) or it will be visible in the final finish. If the final appearance is textured then it may still be necessary to re-level if the texture profile is smaller than the grout profile.

Do you want to see the grout lines or not?

It  sounds like the answer would be obvious, but not always. Showing the tiles can look ok and can actually be the desired look for some.

Additional advice that I recommend you pass on to the floor owner -

- You can’t control if the tiles start to shatter, crack or delaminate when you’re preparing the surface. If it does, there will be a point where it becomes cheaper to remove the tiles and start from concrete rather than overcoat.

- You can’t control if a tile that was not “drummy” becomes loose and causes a failure of your coating sometime down the track.

Both of the points above suggest that removal of the tiles might very well be the best option in a lot of cases.

Note – In the photo above, you can see a great looking decorative epoxy floor done over tiles. In that instance you can’t feel the grout lines when you run your finger over the surface but you can certainly see where grout lines were. In this case the client was happy with the result as he did not seek a flat finish to start with.

Take care and talk to you later,

Jack

22 Responses to “Can epoxies be applied over tiles?”

  1. [...] Can I coat over tiles? « Epoxy School [...]

  2. Jordan Sneake says:

    What a great blog! It’s a pity that i can’t find your rrs address. If you can offer rrs subscription service, i can track your blog easier!Jordan Sneake

  3. marissa says:

    hi. i was excited to find your post as i have been looking everywhere on the web for info on using epoxy kits over tile. your blog came so close to helping me…..but what if you don’t want to see the grout lines/ghosting….then what should you do to prep the floor so that the epoxied floor appears seamless and clean…no underlying outline, etc of tiles/grout??? thanks for your help

  4. Sorry for the delay, for some reason I did not receive your comment.
    The ghosting effect can show up more depending on the type of finish you have. Obviously textured finishes tend to conceal or break up ghosting lines. However the use of metallic decorative pigments can show even the faintest grout lines.
    So there are a few things to keep in mind. Firstly you know to grind the tile to remove the glaze or sealer. You can then either scratch coat the grout lines, or you can flood the floor with resin, covering the grout lines and the porous open tiles. Be aware this might need to be a two step process as the grout lines might be slightly more porous than the ground tiles and hence if you try and do it in one step you could still end up with a slight indentation along the grout line. So seal the ground tiles first and then flood it with resin.
    It is not cheap to overcoat tiles, hence why it is often a 50/50 decision whether to rip up the tiles or overcoat them. Many people will favour ripping them up because then there is no chance of a tile becoming drummy in a few years time underneath your epoxy floor.
    Take care
    Jack

  5. Jürgen says:

    Hej Jack,

    Superdejligt med en blog som din.
    Jeg har sorte granitfliser på mit gulv. De er ikke glaseret men er med glat skinnende overflade. Kan der lægges epoxy på disse fliser, (jeg vil ikke dække dem til, men fliserne bliver meget glatte når de bliver våde, derfor overvejer jeg om en epoxybehåndling kunne gøre dem mere skridtsikkert)

    m.v.h.
    Jürgen

  6. zafer erbatur says:

    I want to learn application of Epoxy Garage and Building Flooring Systems.

  7. Fanni says:

    Good points all around. Truly apprecitead.

  8. Hello Zafer,

    Sorry I seemed to have missed your comment.
    The easiest way to start learning is to take a look at the coaching program offered. Once you have some background information then you start to do some of the flooring systems that I teach in the program.
    Take care and talk to you later,
    Jack

  9. HMT says:

    We had an epoxy floor laid over existing tiles and I was prepared to see subtle images of the tiles underneath which I have. However, in some areas the grout line is not only visible, but I can stick a credit card in the exposed grout line. The contractor is telling me this is my fault because I went for only a 50% flake overcast.
    I feel this is just poor workmanship which I can deal with if he comes back to fill these exposed grout lines.
    Am I unreasonable and expecting too much? The areas in question, ( there are several ) look like a do-it-yourself project.
    Please advise.

  10. george says:

    Dear epoxyschool,
    i have a queery, i want tolay tiles on top of other tiles in a business premises, the tiles are glazed and about 35 years old, it cannot close it operates 365 days per year. But only closes at nights between 5pm and till 8am the next morning. the floor also needs to be levelled out to get a fall for the water to go into the wastes. is it possible to spray or apply an epoxy base glue to the existing tiles and wait till it dries. and then pour over the epoxy levelling cement another night, and wait till it dries before applying new tiles. will the epoxy act as an adhesive for the levelling cement as in some parts it will be very fine when poured over. will it hold the fine levelling cement in place until the new tiling is done. or do you have any other suggestions in la levelling compound that will be very tough when poured over the next day for traffic, until the new tiling is laid down. Ive used floor levellers many times before but only set hard were its 5 to 10 mm and over in thickness to be trafficable after drying. thanking You

    GEORGE ( CEO OF MY OWN CONSTRUCTION AND DEMOLITION COMPANY )

  11. Hello George
    I am not quite sure if I am the best person to ask this question. I have seen plenty of tiles on tile jobs but they don’t appear to use epoxy products. It tends to be more like mapalastic (Mapei) and then tile adhesives. Epoxies may be used but my gut feel is the tiling world will have the answer you are looking for.
    Take care
    Jack

  12. Carol says:

    Is it possible to pour clear epoxy over the tiles to level the floor and still show the beauty of the tile?
    I like the pink tile and dark grout. I just want it to be flat…

  13. Hello Carol,
    The generic answer is …From my experience I have never been able to get consistent and reliable adhesion to glazed or sealed tiles without mechanical preparation. In theory you can etch the glaze with aggressive acids (hydrofluoric) but it is not a nice acid to work with and again the adhesion may be an issue in places.

    Now specifically to your case, if you have your heart set on the idea then you should do some practical tests to prove whether or not your situation could work. This means finding an area somewhere on your floor (perhaps in a cupboard) where you can do a small trial. Simulate the preparation and apply the resin. Allow it to cure for a week or two and then see if you can lift the epoxy layer by cutting, chipping the tiled area as well as the grout line. Imagine what your floor is going to be subjected to and then do it to your trial area.
    If the tests look promising then you have need to decide whether you want to take the risk or not, because a simulation is exactly that… a simulation. You may encounter a slightly different situation on the floor when you do the whole thing.
    Now if you are going to proceed then we probably should discuss a few more matters too covering the state of the grout, contamination, how to apply the coating so you dont get grout line shadows in your finished floor, etc.
    I hope that helps…..
    Take Care
    Jack

  14. Dorian says:

    Hello,
    I have a tiled shower but there is a low spot where the water stays…
    Can I use epoxy to fill the gap( less than 3/8 of an inch) and a thin layer all over to make it even?
    Thanks

  15. Simple answer is yes. you could look to infill but I think you probably should take a look at the reply I sent to Carol as that covers the critical things to consider.
    You will have some additional difficulties because you need to infill on a slope (using a clear I presume), so you will either need a clear thixotropic resin or multiple thin coats. However first things first…. take a look a the reply to Carol and come back to me after that.
    Take Care
    Jack

  16. Dorian says:

    Hello Jack,
    I’m sorry you’re right ,you already answered my question .
    I think I’m going to make multiple coats it’s easier .
    Where can I buy this product and which brand would you recommend ?

  17. Hello Dorian,
    Where are you located?

  18. Dorian says:

    I’m in Toronto

  19. wes says:

    Do you think I could epoxy paint over pool waterline tiles? What type of disc should I use on a grinder to get the glaze off?

  20. Hello Wes,

    I think you might be pushing the boundaries on that application.

    Lets assume that we can get a bond to the tiles, I am not sure that the epoxy won’t discolour if it is at the waterline? Often with painted pools they will keep the paint below the water line and install tiles at the waterline so as not to discolour with UV.
    If you are happy with the potential for UV discolouration then you might need to do a bit of trial and error to see if you can grind without damaging the tiles.
    Are you wanting to change the colour of the tiles or infill the grout lines and conceal the tiles? Lots more questions to follow if you still want to explore this path….

    If it was my pool, and I felt I wanted to change the tiles at the waterline, I would have to favour the idea of removing and replacing the tiles. It may not be easy or cheap but there are perhaps a few too many things that can bite you on this one.
    Sorry, probably not what you wanted to hear.
    Take Care
    Jack

  21. jana says:

    Hello Jack,
    I am looking to improve the look of a basement. The previous owner had painted over the tiles with what i can only assume is garage paint… There are now scratches and marks I would like to tidy up, but given the surface is close to 1500sqft i am hoping for a cheaper solution than replacing the tile. The paint is in otherwise decent shape and does not seem to peel (except in one area where I suspect a garbage bin or leaky container of sorts has been kept). Do you think it makes sense to use some epoxy based paint on this? Would I need to try and strip the existing paint or just sand down mildly?
    Many thanks in advance!

  22. Hello Jana,
    It will come down to what you want to do in your basement and how much you want to spend.
    It may be possible to overcoat the existing “paint”. Although you should do a test patch because the area that peeled does not sound encouraging. If it is a basic paint then it may not like the coating you put over the top.
    If all your efforts are just to pretty it up then by all means look to overcoat. However if you floor is going to be subject to some impact, wear then you may actually consider bringing in a dustless diamond grinder and removing the paint as well as the glaze on the tile. Not typically a DIY and yes it is going to add up to some dollars but you may need the floor to last rather then repaint it every year or two.
    I am sure that answer has raised a bunch more questions, so feel free to ask.
    Take Care
    Jack

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