Sign In to join the community | Help

Concrete subfloor prep for tile


I'm doing a tile project in my home which involved me pulling up the old linoleum floor in the kitchen and laminate wood in the living room. The wood came up easy enough as it was floating, but the linoleum had to be scraped. I first peaked it up then used an adhesive remover to pull up remaining paper. What is left is very smooth, but I can see lines of what looks like swirled from trowel marks from the glue put down to secure the linoleum. Am I okay to tile over this now? Also, in the living room there is over spray along the walls from where the painters sprayed the trim below where the wood was.

Not what you were looking for ? Try posting a question
Posted 2018-08-01T17:26:01+0000  by NickD NickD

Hey NickD,

Thanks for your question and welcome to the community.

As long as the majority of the adhesive is completely removed, then it is possible to place thin-set mortar for tile over it. 

However, if the subfloor is wood, I would recommend to either replace it or go over the existing subfloor with tile backerboard. If the subfloor is concrete, then no worries in terms of using tile backerboard.

I'm not sure what you are asking in regarding to the overspray of paint along the walls where the trim was. Did you want to repaint this, or touch up the area specifically? Let us know, and we can assist further.

Hope to hear from you soon,


Posted 2018-08-01T22:01:24+0000  by Joseph_HD_ATL
Regarding overspray, when the paint contractor hired by the builder originally painted the trim for the home (there was no flooring of course), they just sprayed the trim, getting a lot of spray on the floor (overspray).  They then, of course, taped off the trim to spray the walls, etc.  So, there is paint on the concrete foundation along the walls from this.  Am I okay to tile over this, or do I need to grind it off?  It doesn't really come up  with a scraper and is smooth to the touch.
Posted 2018-08-02T22:57:45+0000  by NickD
Hello NickD.

Ideally you should grind off the paint.  The strength of the mortar bond to the painted area is only as good as the paint bond to the concrete.  If we are looking at a thin border just along the wall where most of those last tiles still bond to unpainted concrete, then you should be OK to just mortar over and set the tile.  If most of those last tiles will be set on paint, then there is the chance that the paint will come loose, and so will the tiles.  I would grind or scrape rather than use any paint stripper, as the chemicals may also prevent a good mortar bond.


Posted 2018-08-03T14:41:33+0000  by Chris_HD_CHI
Not what you were looking for ? Try posting a question