Tiling Over Painted Concrete: Can it be done?

Discussion in 'Shower & Bathtub Forum & Blog' started by johnfrwhipple, Jan 29, 2014.

  1. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,713
    Location:
    North Vancouver, BC
    You need not be in this business for long time before the pickle of having to work over a painted concrete surface comes up. Front deck. Back patio. Basement mudroom or ground floor laundry room you need to figure out this step before going to far along.

    I do not know of any product designed to work above or onto of a painted surface (concrete). That said I have tried a few approaches over the years.

    On my old front deck (12 years ago) had flaking painted concrete slab. Nasty. Paint flakes all the time getting tracked in.


    [​IMG]

    I rented a pressure washer and hit the front porch hard. Then I used my wire cup wheel and grinded the surface.

    [​IMG]

    Then more water.

    But - the surface was still littered with paint and I said **** it and went right over top with my tile prep. This was the firs time I used Grani-Rapid from Mapei to set Ditra. It worked really well. The Ditra sat down nice. The slate tile went it. I grouted with Ultra Colour Plus and for over nine years this black slate tile on my North exposure served me and my family well. Since then we have removed this front deck and added a floor to my home.

    My new back deck is tiled and this time I worked over new construction. The slate tiles installed over NobleDeck, over cement board, over double ply, over double 2"x10"s on 12" centres. A TANK.

    I have tried basic thin-set - unmodified and it sticks so poorly to a painted surface you might choose to instead burn your money versus spending hundreds of dollars and have tiles popping up.

    You need a bond. And the weakest point is the paint. If the thin-set reacts with the paint and weakens the paint you are screwed. So - how do you check?

    Do a test. Set a little tile over the painted concrete after you make every measure to rough up the surface and remove and loose bits. Leave it for a couple days. Then bash it off with a hammer.

    What happens?

    Did it come off to easy.

    Did it shatter and stay stuck to the floor.

    Did the paint peel away and the thin-set is still stuck to that.

    This should give you a basic idea of how things are working.

    Now if you can not get a chemical bond then you will need to switch to a mechanical bond. Visions of 1/4" wonder board and expanded diamond lath come to mind.
    Last edited: Jan 29, 2014
  2. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,713
    Location:
    North Vancouver, BC
    Tiling over a painted concrete surface: Renting the right tool for tile prep

    One of the best tools for prepping this job is a shot blaster or a scarifier machine.

    Big tools for big jobs and they make a Big Mess.

    [​IMG]

    You can see the improved results for these specialty rental tools....

    Learn more about Scarifying your floors here.
    Last edited: Jan 29, 2014
  3. guy48065

    guy48065 Member

    Messages:
    117
    Location:
    SE and north MI
    The old test for interior paint adhesion was a Band-Aid. If the old paint came up when you pulled off a Band-Aid, you need to strip.
    I would think a similar test using a strong duct tape (or other instant-sticking adhesive) might be a good indicator of how sound the substrate is.
  4. dhagin

    dhagin builder:anti-builder

    Messages:
    108
    Location:
    oahu
  5. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,713
    Location:
    North Vancouver, BC
    The Paint Pull Test prior to tile setting

    Wow Dana - you are just like Jim. Dana here is a pretend contractor and he felt compelled to share a link on nothing. We are discussing tiling over painted concrete and the link he posts show no information on it. So many people it seems are compelled to pretend to be builders. What is it with you Dana? And you Jim? Are you sad that you aren't a contractor?

    Dana is one of John Bridge's top posters with 10,000 plus posts over there. His presence here I guess direction from CX or John Bridge to post more cut and paste info onto Terry's forum and support Jim. Jim needs support since he appears to be grasping for content of late. This happens when you do't work for a living and generate your own stuff to talk about.

    So thank You Dana and the John Bridge forum for a random link.

    Now the Band Aid test is awesome insight. I've never heard that and I like the simple test measure. I would think "Tuck" tape is a good tester as well. That shit sticks to everything.

    [​IMG].

    Perhaps a simple pull test will confirm what you all ready know - the paint must come up!!!
Similar Threads: Tiling Painted
Forum Title Date
Shower & Bathtub Forum & Blog Tiling over bath tub flange May 13, 2014
Shower & Bathtub Forum & Blog tiling shower floor in seperate sections Apr 5, 2014
Shower & Bathtub Forum & Blog Tiling bathtub walls help - tub flange too far. Mar 6, 2014
Shower & Bathtub Forum & Blog Shower Retiling: When to ReTile That Old Shower - How, What, Where and Why Nov 7, 2013
Shower & Bathtub Forum & Blog Tiling directly to Exterior Glue Plywood (EGP) - Tiling Tips Pros and Cons Jun 28, 2013

Share This Page