How to Cut Door Jambs When Laying a Tile Floor

Before laying a tile floor, you need to trim the bottom of the door jambs and casings to the right height so the tile can slip under it.

To trim door jambs and casings for tile on a concrete slab:

  • Put a few sheets of newspaper on the floor to act as a spacer.
  • Place a tile upside down on top of the newspaper next to the door jamb or casing.
  • Position a handsaw flat on top of the tile.
  • Use your finger to hold the saw flat—and cut through the door jamb or casing.
  • Remove the scrap of door jamb or casing.
  • Install the tile on the concrete stab using thin-set adhesive.
  • When installing tile on a wood subfloor, a layer of 1/2″ cement backer board needs to be installed first so the tile will adhere properly.
  • To trim door jambs and casings for tile on a wood subfloor:
  • Put a tile on the plywood subfloor.
  • Place a scrap of backer board on top of the tile.
  • Use a handsaw to cut through the door jamb or casing.
  • Remove the cut scrap of door jamb or casing.
  • Attach the cement backer board to the floor, extending it under the door jamb or casing.
  • Install the tile on top of the backer board using thin-set adhesive.

Watch this video to find out more.

Further Information

Danny Lipford: Anytime you’re installing a ceramic tile floor, or any type of new flooring, there’s a certain amount of preparation that you have to do to the existing subfloor. Now here on this concrete slab, we removed the old vinyl floor, scraped off all of the glue, a little bit of floor patch here and there. Now we’re looking at a little preparation on the existing trim work.

Joe Truini: In this case, Danny, where we’re installing the ceramic tile floor up against the door casing, a lot of homeowners make the mistake of thinking they need to trim the tile to fit the door casing. In actuality, you do just the opposite, and here’s how.

First, slip a few sheets of newspaper down in front of the casing, and then put a tile upside down so you don’t scratch the surface. Then you can use a handsaw to trim the casing to length.

Hold the fingers flat on top of the saw, so it cuts nice and straight. Flip out that little piece, and the tile will slide right underneath.

Danny Lipford: Now this is a concrete slab. If you were working with a wood subfloor, you would first need to put down cement backer board, and then install the tile over it. In that case use a piece of the backer board as a spacer, instead of the newspaper.

Either way you get a good finished appearance. Then you’re able to take your baseboard, and sit it right down on top of your new ceramic tile floor.


  1. the remodeler I had took up laminate and carpeting and then he routed underneath the baseboards and underneath the door jam without knowing the thickness of the tile when he contracted a tile layer he didn’t tell him the thickness of the tile he told him he did not know it was going to be the wood like porcelain tiles even though I had showed him my question is how can I fill in underneath those door jams I know I can put the quarter round around the baseboard thank you

    • Hi, Kerry,

      Danny says, “The gap that you’re speaking of would need to be filled with a material that would allow you to sand, prime and paint it. There are many good wood putties that would work very well for this and I would recommend applying it with a thin-bladed putty knife.

      “You may also consider using something we use frequently in situations like that, which is automobile filler, with the most common name being Bondo.

      “However, your best bet may be to use a good-quality acrylic latex caulk with the putty knife to smooth it out; it may be all that you need.

      Good luck!”

  2. I wish the video had shown how he held the saw with his left hand to do the cutting. I gather he did not grip the handle in the normal way, which would result in some painful knuckle scraping against the floor. And, how is he managing to get a level cut when the thickness of the saw handle itself interfere with this objective?


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