How to Lay Tile on a Concrete Slab

Can I lay ceramic tile directly on a concrete floor? -Michelle

Hi Michelle,

As long as the concrete slab is clean, flat, and free of active cracks, you can lay title directly on the concrete floor using thin-set adhesive.

Small cracks caused by shrinkage usually do not present a problem; but larger cracks, especially those that are higher on one side than the other, may telegraph through the tile and cause it to crack.

To find out if a concrete slab is clean, pour a little water on it in spots. If the water soaks in, you’re good to go. If the water beads up, it may indicate the presence of oil or wax which may cause adhesion problems with the thin-set.

To remove the oil or wax, clean the floor with a solution of TSP (trisodium phosphate) and water using a scrub brush or stiff broom. Rinse the floor with clean water to remove any residue, allow it to dry, then test it with water again.

Fill in any low spots on the slab with a self-leveling floor patch compound. Follow the directions on the container, and allow the compound to dry the recommended time before proceeding.

Good luck with your project,


Further Information


  1. Good morning Danny,

    I’m having to cover my Dad’s front porch walk-way into his home. It’s concert and I would like to us tile anyway to do this? Was watching your show today and I like the new tile system that just locks together.

    Thank you for your help

  2. I installed 12×12 tile over good dry “old” concrete slab. 2 days latter I was going to grout the tile and some of the tile were loose. I could slide tile around and pull back out of the adhesive. 90% of the tile are “stuck” solid What went wrong? The tile that are loose the adhesive is not set up and can be scraped off both the concrete and the tile.

  3. Hi
    I have a sloping ramp to enter my bungalow and it is made of 3×2 concrete slabs, I painted them with a well known brand of masonary paint and throughout the summer they looked great. During the winter they began to blister and peel and the ramp has become very slippy. I do not know what to do as this paint obviously does not work, could i tile over the slabs with a rough surface toe or different coating?
    Any suggestions most welcome!

  4. I have a large cement porch and pathway in my front yard. The porch has a number of cracks that are long but not deep and only about 2-3/8ths wide max. I am looking for the best option to cover the porch and continue down the pathway. I porcelain tile the best option.

  5. Quick question a homeowner of mine wants me to lay his porcelain tile in the morning at 8 and he wants to be able to use it that evening around 10pm. Is this possible? Do i need a special thinset?? Thanks in advance

  6. I had some tile work done throughout the house (done on a slab) where new tile was laid and the new tile is very uneven in certain areas. The contractor says its because the floors were uneven to begin with. Should something have been done to make it even before the tile was laid or is he correct since it is an older home?

  7. I want to install ceramic tile in the bedroom. The foundation is concrete slab. /for one outside wall, the concrete ends about 1 inch from the wall. The builders put down some sort of filler (not concrete) for this large gap. Do I need to fill the gap with concrete before laying the tile?

  8. I want to cover a raised cement slab with porcelain tile. However, there are outdoor garbage cans that are rolled up the slab step onto the slab. How can the tiles be laid to insure that the garbage can wheels do not loosen, crack or chip the edges of the step up onto the slab?

  9. I have to replace approx. 8′ of outer edge tile that a riding mower keeps breaking. I purchased an 8′ length of 3/8″ RENDEC Anodized Alum. Finish. The 5/16″ tile (I assume) is to fit inside this edging. The tile will nor slide into the slot and the H/W store does not carry anything larger then 3/8″ opening. Am I susposed to somehow expand the opening which I don’t think l can?

  10. Hi there

    I am wanting to tile around my fire place. I have just used a jack hammer to get the existing tiles up and this has left the concrete quite uneven. What do I need to do to it before re-tiling?


  11. I had an indoor french drain installed, I had to remove 2 rows of Vinyl commercial tile ( VCT ) After the drain was put in they added gravel, then fresh cement. I know I have to let the new concrete cure before installing the replacement tile ( 12″ x 12″ ) Do I need to seal this new concrete as it meets up with the old basement slab?
    Thank you in advance.

  12. If you are putting tiles on a concrete porch, do you tile around the existing porch post columns that support the porch ceiling? Or do you need to lift the posts and slide a tile underneath them? Wouldn’t tiling around a post create a little water dam around the post and cause the post to rot? Please explain how you handle the porch posts during installation of the tiles. Thanks.

    • Hi, Jean,
      Great questions! We have forwarded them to the Today’s Homeowner Radio Show’s producer.
      He will contact you soon to discuss featuring them during an upcoming show.
      Take care!


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