My question is about preparing a concrete floor for ceramic tile installation. I have chipped out the old ceramic tiles from my condo. kitchen and foyer floor. What remains is the concret and bumps from the old mortar (picture attached). Before I install new ceramic tiles do I need to:
1) Chisel out all of the old mortar to get to a “mortar free” concrete surface?
2) Leave the old mortar lines and tile overtop?
3) Apply a skimcoat to even out the old mortar lines?
The floor is level and even, so I do not need a skimcoat to even out differences in height.
This is my first tiling job and it’s a small, safe, rental space area so it’s a good little project to learn from. I would appreciate some advice on doing this the right way.
Replies
Picture attached here.
Is the mortor "tight"???
The scores in the floor are they the mortar or chisel marks???
scrape / chip off everthing that is loose and float on floor leveler to make everything flat..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Those are mortar marks, not chisel marks. It's pretty tight and tough to remove.
Grinding them off sounds good but the space is pretty confined (small condo kitchen) and the tenants are using the kitchen during the week.
If you use a skim coat instead of removing the old mortar, you're going to have a thicker floor. It's a kitchen, right? Can you tolerate losing more space under the counter where the dishwasher is already squeezed in?
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
BTW
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
If hand scraping is a pain, a concrete floor grinder (rented) will remove thinset.
Remodeling Contractor just outside the Glass City.
Quittin' Time
I appreciate the different considerations that are being presented. I just need to know my options for now:
1) Must I chisel or grind out all of the old mortar to get to a "mortar free" concrete surface? OR
2) Can I leave the old mortar lines and tile overtop? AND
3) If I can exercise option 2 do I have to apply a skimcoat to even out the old mortar lines?
Somebody please help me with these questions. I'm just interested in "the right way" of doing this because I've never done it before.
Clean is best....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Thank you. That was the important tip that I needed.
A combination hammer or a demo hammer from yur rental outfit with a chipping chisel would probably be yur best bet...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
If the old mortar is solidly adhered, and is not so high that when you apply thinset, place the tile, and push it down to its final height that it does not hang up on the old mortar, then you can just leave it be. It would only be a problem if the new tile rested up on a hard spot of old mortar, which would create a stress concentration.
I recently did a re-tile of a kitchen (about 400 sf) and an entry (about 200 sf) where I had to demo ceramic tile on a concrete slab. Did the kitchen first, and took off just what I had to ... noithing more. When it came time to do the entry, I scraped it clean ... looked like the day beofre they installed the original tile.
I thought I had the kitchen floor level enough, but it was tough to trowel on the new thinset, and I "found" several places where the old thinset was just a teensy bit too high. It's no fun trying to chip off a little slag of old thinset when it's surrounded and covered by fresh stuff.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
yeah ...
no matter how "close" ya think you got it ...
"good enough" .....
you usually end up finding out things ain't so flat come tile laying time.
I was tempted to say he could go on top if things were "flat enough" ...
but for me, at least ....
they're never been in the end.
fights ya every step of the way if you don't shoot for near perfect from the start.
Jeff
Next time save yourself some work and tile over existing if tiles are sound. Now you can save work by mixing up some Jif-set really runny and pour it on.
Anyone have experience with the Bosch $400 5" Concrete Surfacing Grinder?
I saw it for sale at H.D. and it piqued my curiosity as to whether or not you could use a regular angle grinder with a special disk and get near enough results for fewer bucks.
Sample description:
http://www.internationaltool.com/boschconcretegrinder.htm
Yeah, no need to spend 400 bucks. Any angle grinder will work especially for a small area. You wouldnt want to do a huge job with it. Most come with a grinding wheel when you buy it. You should also get a diamond wheel for your grinder for making irregular cuts in the tile. So if you are on a budget you could use the grinder and a scoring cutter. Roto-zip is cheap too and will work on wall tile and cement board. It still wouldn't hurt to pour down some Ardex or Jif-set to level things out. Then you wouldn't have to chip and grind so much.
Clean it up as good as you can, damp mop it, bonding agent, then skim coat of thinset with isolation membrane set on top.
Skim it by using a 1/4 notch, then knock em down with the flat. if you hit a big lump, smack it with a hammer, it'll pulverize it. Just watch for where the splatter goes. been there, done that, worked fine.
Done.
Eric
I Love A Hand That Meets My Own,
With A Hold That Causes Some Sensation.
Edited 10/19/2004 4:34 pm ET by firebird
Edited 10/19/2004 5:53 pm ET by firebird