I would like to know what steps to take to prepare the concrete floor for ceramic tile. Part of the floor is cement and part is painted. Do I have to prepare the painted portion before tiling?
Rent a floating machine and skim the floor with thin set mortar. That eleminates imperfections in the slab, giving you a first class substrate for your tile. If the paint on the concrete is tight (not flaking or peeling) you should be able to skim right over it. The machine is a large, electrically driven circular trowel that really smooths things up.
Do not attempt to try what Ray is suggesting ( sry Ray) DIY Doc is rt.. THin set morter is a bonding agent not a filler.. If to thick it will crack and skrink . There are better product s for coatind and filling, such as self leveling compound. but thats a differant situation. Your cement floor is an excellant substrat like Doc said. The only thing I like to do diff is allow the thinset to dry dry an extra day specially over the painted part Other than that GL 20 yr installer
I tile every day of my life and since the paint is assumed to be part of some aesthetic over concrete, you can scuff it with a wire brush, belt sander, grinder, cleaning all debris. Beyond that, concrete, unless sealed, is a prime substrate for tile/mortar. Certainly you should check for level, as in depressions or any rise, then proceed as is standard Measure snap two perpendicular center lines adjust those lines for cuts and the least waste work from deep in to an exit point test level with a level or hand use a 1/4 in. toothed rectangular trowel to spread mortar use a poly based mortar use rubber spacers at 1/4 or 1/8 inch do not press aggressively save cuts and cut installs for last and do not attempt to kneel on tiles installed to add a piece missed perhaps remove cove base if it exists to replace later wait no less than 24 hours for dry/set time use Poly blend grout of you choice in color mix both mortar and grout to mashed potato consistency fill grout spaces after removing spacers use a rectangular rubberized spreader/squeegie wipe with a barely damp sponge first time then in 2 or 3 re-wipes as the grout sets you can increase dampness (grout sets faster than mortar) by the third wipe of grout excess you should be ok and notice upon drying a DUST that can easily be mopped away after the fact. allow 24 hrs for grout dry/set If you have a pedestal sink, pull it. Pull the toilet as well Tile to the sewage drain flange and replace with a new wax ring with a rubber flange extender embedded. Mop clean after two days and enjoy Steven Wolf Just my two sense
