A quick post about removing paint or any other finish from concrete or wood before installing tile. About half of the time when we show up to a concrete floor to install tile we find that the floor has been painted. In a basement homeowners will do it to make the surface a bit more 'finished'. This paint becomes a problem because our tile will only stick to the floor as well as that paint is stuck to the concrete. We always grind off this paint. If you're spending good money on tile, you obviously expect longevity (as you should) It's imperative to have a clean concrete surface to apply the thin set to. In the past we've torn up tile applied over painted floors and that's a dream situation for us because the tile comes right up. That to me is evidence that a floor has to be clean of ALL past coverings. Don't be fooled by a dismissive builder who states that you don't have to do the grinding because your tile will only be stuck to the floor as well as the paint.