I am going to replace the tile on my kitchen floor. Part of the kitchen floor (~25%) covers an area by a sliding glass door, that was added onto the kitchen. This area used to be a porch, and has since sunk a bit since the addition was put in (we estimate it has been there since the '70s). Consequently, the floor on that area is on a slight downward angle, compared to the rest of the level floor.

I want to lay down long tile in a herringbone pattern. I'm afraid that if I lay it down on the existing subfloor, the tiles that straddle the point where the floor changes slope, will eventually crack/break.

Everyone I talk to say I should lay down self leveling concrete and level the entire floor, but I'm looking for alternatives on how to handle this situation. Any ideas?

3 Answers 3


Assuming that you have a suitable subfloor (at least 1-1/4" thick and not particle board), and that the floor isn't settling further with time, there's no reason to expect that cracking will occur. Your thinset mortar, properly applied, will support the tile and prevent movement.

That said, it may be wise to look at using a self-leveling material to flatten things out beforehand. You don't say how much the slope ends up being, but a 3/8" by 1/4" notched trowel can only accommodate so much change in plane before voids start to occur.

  • Thanks. The slope makes a 3/4'' inch drop at the end. Does that change your recommendation?
    – Dan Largo
    Commented Aug 7, 2016 at 22:07
  • Only that I'd definitely seek to level the floor for aesthetic reasons. It could be that the door threshold doesn't allow that much of a height adjustment, though.
    – isherwood
    Commented Aug 8, 2016 at 0:53
  • I had a feeling it would come down to that. Do you recommend using self leveling concrete, or is there another method that I can use to help get that part of the floor level (or more level) with the rest of the floor?
    – Dan Largo
    Commented Aug 8, 2016 at 10:58
  • It's hard to say without more information. Let's not hold a lengthy conversation in the comments, though. Feel free to accumulate some photos and post a new question.
    – isherwood
    Commented Aug 8, 2016 at 13:12
  • Sure. Please make sure to upvote all helpful answers.
    – isherwood
    Commented Aug 8, 2016 at 16:00

If you have a floor that is sinking or sagging, I would seriously consider whether it is sufficiently able to handle tile. If the floor has a bounce to it, you're going to constantly be having grout breaking out no matter whether you level it or not. Tile requires more infrastructure than other flooring options, so, without knowing I'd at least say reconsider or have an expert at least look at it for you first.

  • Thanks. The floor is stable, and has not changed in years.
    – Dan Largo
    Commented Aug 7, 2016 at 22:00

An alternative would be to have a grout line at the inflection point where the angle changes. So run the tile perpendicular to the way you were going to run it and start where the angle changes and have that be a grout line. This way no tiles cross the angle inflection point.

Also, don't use grout there use a sanded caulk of a matching color. The manufacturers of the thin set mortar and grout make matching sanded and unsanded caulk. Usually used to create an expansion strip.

Good luck!

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