removing old tiles?

Question

I'm taking up the old tiles in a kitchen. Since I need a level strong subfloor for the new tiles what is the best way to do this? I was going to scrape and possibly sand or grind the old mortar down so I would have a new base. My concern about placing hardibacker even 1/4" is that this would now raised the level of the floor higher than the adjacent living space (open flr plan)

Answer 1

What kind of subfloor do you have? If it is wood and you have a basement or crawl space below it, you have no choice but to put down the hardibacker. Otherwise, the wood subfloor will flex when you walk on the floor and tile does not flex, they will crack and the grout will come up and you'll have a mess. Break up the old tiles and use a scraper to remove them, grind down the old mastic or thinset and prepare the subfloor for the hardibacker. You will have a level change from one room to the other, no helping that, but you can use either a reducer or bullnose tile at the point of the level change. Only way to avoid a level change is to remove the subfloor entirely down to the joists. Then you can put in the appropriate thickness of hardibacker. Of course, if you have a concrete foundation, you don't need any other subfloor.

Answer 2

3/4" exterior grade plywood, with 1/4 Hardibacker on the floor joist should give you the strength you need. Never use luan in any tile application.

There is also a product on the market called Dietra-mat, so after you scrape the floor down, you can place dietra-mat, and then tile to that. The theory is Dietra mat absorbs the movement so that the tile won't crack. Dietra mat is made by Schluter and you could check out their website for product information.

Answer 3

You raise a good question. Generally speaking - it really depends on how old and brittle the mortar is. If it flakes away easily, sanding may not be that bad. If however it does not sand - you may be forced to use a floor scrape - which unfortunately can easily damage the sub-floor. I would probably go the route you are already on - try sanding first - and then as a last measure use a scraper.

Answer 4

First of all do not use 1/4 inch anything, but do scrape and smooth the remaining substrate.

Transitional threshold type moldings are sold, covering a relative easy pass from one height to another, especially in fractions of an inch.

Steven Wolf
(The Rev.)

Answer 5

we had to do that in our kitchen. we took out the entire subfloor, down to the base board. it is a lot of work but it was worth it b/c now our floor runs seemlessly from the kitchen to the living room (both hardwood). You might want to think about doing that

Answer 6

Personally, I'd lay 1/4" luaun on top of it.
After you get the tile laid, you can buy a step-down transition moulding to bring it down to your other surface.