How to Tile a Bathroom Floor

Tile can be laid directly on top of an existing tile floor as long as the old floor has been cleaned thoroughly first. For this room, porcelain tile was used, which tend to be more durable than ceramic tile. To make a small bathroom like this one feel larger, the tiles were laid diagonally.

Start by popping chalk lines on the floor from the center of each wall to find the exact center of the floor. To keep the chalk lines from smudging, spray them with hairspray.

The first tile was positioned diagonally in the center of the room and pencil lines drawn around it. The tile was removed and thin-set tile adhesive applied to the floor with a notched trowel.

After the tile was positioned on the floor, it was pressed firmly into place.

When the first tile had been laid, additional thin-set was applied to the floor, and the adjoining tile aligned to it using plastic spacers.

The curved cuts in the tile for the toilet flange are cut using a portable wet saw.

The cuts are then fine-tuned with tile nippers.

Once the tiles around the toilet have been cut, they are laid in place.

A tile cutter is used to make the straight cuts against the walls. After the tiles are scored with the cutter, they are snapped in two along the line.

Once all of the tiles have been laid and the adhesive has set, the joints between the tiles are filled with grout, and the bathroom floor is ready for installation of the vanity and toilet.


  1. loved your video could you demonstrate how to tile a bathroom when there is a drainage on th floor? (how do you get the water to actually move towards the drainage ( in case of flooding?)

    • Hi Larry,
      Sorry you had trouble with the video playing. It played fine for me when I tried it on my fairly slow DSL hookup. It’s possible the 5min video server was experiencing problems, or it may have been a problem with your Internet provider or your connection speed.

  2. Hi – The video was very helpful but what goes between the edges of the tile floor and the wall? I don’t see grout in the picture.

  3. Hello,
    I’m getting ready to tile my bathroom floor and walls, after putting the backerboard down on the floor I’ve found that some of the screws aren’t flush and I can’t get them any deeper. What to do?

    Also, do I have to put backerboard on the sheetrock walls before tiling the wall?

    • Hi Slade,
      Some screws have nibs on the bottom of the head that act like a drill so they cut into the surface to countersink the screw flush when you screw them in. Otherwise, you would need to take them out, countersink the holes, then screw them back in. As far as the walls go, if they won’t receive excessive moisture, you can tile over drywall. If the tile is around a tub or shower, then waterproofing measures need to be taken with a layer of plastic or waterproofing compound followed by cement backer board. If you’re starting from scratch on the drywall in an area that doesn’t receive a lot of moisture, you might want to use the green drywall which resists moisture better than standard drywall. Good luck with your project!

  4. I have a wood bathroom floor that has sagged unevenly, especially towards the center of one long wall. How do I level the wood floor without removing the subfloor and sistering each joist? Or is that the only way to do it?

  5. Hi Danny:

    This website has some valuable information and I thank you for making it available. Backer board and ceramic tile was installed on our bathroom floor on December 14, 2010. We went out of town on December 15, 2010 and returned December 19, at which time normal usage of the bathroom commenced. Within days, cracking and fracture lines were visible. What should we request the contractor do to correct this problem? We can be reached at the email noted above or at 757-753-1221.
    Thank you for your assistance.


  6. Also, I am sure that the installer did not tape the joints in the backer board and apply thin-set adhesive to those joints. What problem can result from not doing this? He applied grout at the threshold between the last row of tiles and the transition strip, but after reading your information, I think he should have used caulk. Lastly, the shoe molding was reinstalled and now we see some cracks in the grout beneath the area where power driven nails were inserted. Please address these concerns and our other email. Thank you.


  7. Want to tile bathroom aprox. 8X12 ft. Wooden 1X6 subfloor on diagonal ( had to replace some when I tore out vinyl floor and wet mush particle board) with 1/2 durorock over top that mu father glued and screwed down. Question: the seams dip and some didn’t meet correctly and are high with one piece to another. Can NOT get the screws to counter sink. Most are slightly above the d. roc board.

    Would I be better off to get some sort of leveler compound (thin portland cement) and smooth over the D. Roc, screw heads and joints or get the Membrane and put over the floor, too. Would that be OVERKILL? I am really ready to do this and now am afraid at what I am seeing-screw heads protruding and bad joints!

    • Hi Deborah,
      You need to use a screw made to countersink in cement backer board, such as Backer-On brand screws which are available at The Home Depot. They have ribs under the head that self-countersink the screw into the backer board. In answer to your question, you should use a floor patch or floor leveling compound to fill any low spots in the backer board (or in the subfloor under it before you put the backer board down) before tiling. Watch our video on How to Level a Subfloor to find out more. Good luck with your project!

  8. We are replacing the bathroom floor and will replace the subfloor plywood. What thickness of cementboaed should we put down ? Do you not have to take into consideration the height of the finished tiles floor to the height of the toilet flange ? Can it be level or must the floor height be below the flange,I read somewhere a tile floor needs to be 1 1/8 inches thick so it won’t flex and cause cracking, is this old info before cementboard??? Thanks Cindy

    • Hi Cindy,
      When tiling, usually 1/2″ thick cement backer board is used over a 5/8″ thick or thicker plywood subfloor, making a total of 1 1/8″ or more combined. The toilet flange will probably need to be raised so it’s on top of the tile for a good seal. You can find out more in our article on Installing Tile Over a Wood Subfloor. Good luck with your project!

  9. Danny,

    I an installing a ceramic tile floor in my bathroom. I want to use 1/4 Haribacker. The floor is 1″ X 8″ plank, what should I use between that floor and the Hardiboard? I have a concern about the height of the shower and toilet flanges, I would not want to replace them if possible.



  10. What do you do with the edge along the bathtub/shower, where there will be no trim going on top? do the tiles go flush to the tub, and if not, do we fill the gap with grout, or with a flexible waterproof sealer (i.e. silicone)?

  11. I am tiling an upstairs bathroom. The floor is plywood and I am hesitant about using hardibackerboard because I believe the height of the floor will be to high. Can you tile directly to plywood? Do I used a thinset? Or that Ditra material?

  12. Hi all. I was wondering if I should leave a 1/8′ gap of backerboard and tile around the opening for the toilet. And, the above was tile before addition of the cabinet. What should I do if a cabinet already exists? does backerboard go uptight to cabinet, and would silicone be appropriate between the tile/wood cabinet.

  13. Hi Jared…An 1/8″ gap is recommended around all perimeters as well as between sheets of underlayment. Also, make sure you’re using a quality modified thinset to adhere the backerboard to the floor. As far as around the toilet, though, I’m assuming you’re pulling the toilet prior to laying any backerboard or tile, right?

    For existing cabinets, same rule applies…give a small gap. Instead of silicone, though, I’ve always provided a slightly larger gap and used my grout to fill in. It just looks better to me.

  14. Dear Sir,We have a second shower and it ceramic tiles .My question is in the corners I get water settling because it is not sloped.Time is not on our hands right now so is there a product that I can use to put on top of the present tiles to slope towards the centre and then retile it with porcelin tiles and if there is sutch a product where can we buy in .We live in the Windsor area (Ontario).Home depot is close by Thank you Regards Jean E

  15. Before I lay down porcelain tile I would like to lay down heated flooring. Can you do a video on that ? Thanks so much. Kris Crocker

  16. I want to tile over the bathroom floor tile but want to know what to do about the height where the carpet meets the tile at door opening

    • Hi, Raymond! Danny says, “There are a number of different thresholds that are available that would allow you to make that transition.
      “I would check at the home center in the flooring section to see the assortment they have available. Good luck!”


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