I am remodeling my main bathroom and I am planning to replace the ceramic tile floors. The existing floor is mosaic tile in good condition except it is outdated and my wife can't stand the look anymore. Under the tile is an 1 inch mortar bed on top of plywood. The floor is very solid, but I want to add a new tile floor.

Is it recommended to remove the tile and existing mortar bed and then lay a new cementboard underlayer before adding new tile?

Is there a easy way to remove the grout/tile adhesive once the old tiles are removed? The tiles come off pretty easily, but the remaining floor is not very smooth.

I do not want to add any more height to the floor by adding more underlayement since the level is already higher than the surrounding floors.

Has anyone run into this and have advice one way or other?

Thanks in advance,

Rudy

Rudy, once you pull up your old ceramic you are going to see a mix of concrete bed and old thinset, it will be very rough. You need to get the old thinset chipped away but if the bed has no cracks it can stay. Did you old floor have any cracked tiles or cracked grout lines, that will tell you a lot about the real condition of the bed.

My existing tiles are all sound with no cracks or loose tiles. There may be 1 or two small mosaics next to the tub that came loose but that is pretty much it. I don't know about under the toilet yet, since I have not removed it but I suspect a small amount of water leakage may have loosened those tiles.

I would think I can remove and repair/patch any of the mud bed that needs repairing. What I don't know is if during the process of removing the tiles if I will end up with cracks in the mud bed.

Any good way to remove the thinset other than chipping away at it?

You will be chiseling almost horizontally so it should not crack the bed. If a crack forms try to remove and entire chunk and repour that section, don't patch it like a crack in a wall.

This isn't as bad as what you may think, you do need to remove the mortar bed and install a backer board then tile. First to remove the bed of mortar, you'll need a large pry bar. The bigger the better, you'll need to hammer down till you get to the plywood then with the pry bar get underneath the mortar bed and the metal lathe, once there just start prying and it will come out in bigger sections, it's a dirty job buy just get into it and it should take more than a hour or so,, depending on the size of the bathroom of course, but definitely get a long pry bar no less than 2ft a 3fter would be best, and a small slegde hammer will work wonders with this as well, good luck

I know how to remove it all (all the mud) and get to the plywood. I also assume that since the plywood gives, it would come apart rather straightforward. I was looking for advice if it is better to leave it (mortar) in place and try to get the thinset off (try to level the concrete) or just remove it all an start over. The mortar is in really good shape, but if the labor to clear it off is more than just removing it and starting over, it might not be worth my effort.

Anyone have experience either way - and regret it one way or another?

I think Glavine and I both have had experience with floor but maybe different experiences. 25 years ago we put down ceramic foyers with a poured slab of cement which you are referring to as mortar, I'm guessing its 25 year old cement. If it has not cracked or allowed your current tiles to crack I think you can leave it in place. Just chip the thinset off with the old tile. If the cement starts to crack and come up it will be in chunks and then you may find yourself at a crossroad. Difficult to patch and difficult to repour the whole slab. If you rip everything out you have a 1" deep hole to fill with backerboard.

On my particluar job I knew from the start that we were tearing it all out from the start, and we had the tools and time to make quick work of it. If your knew to this and are unsure or nervous about getting that involved with the project then ballengerb1 way will work fine. Either way will work and none better than the other, Ive never tried to save the slab either time I did it. But in your case if you can get the tile up with out tearing chucks out of the floor then by all means work smarter not harder.

Thanks for the advice. This afternoon I tried to first remove just the tile. This was pretty easy but left an uneven bed for the new tile. Since the new tile is going to be thicker than the old and the bed was so uneven, I removed the entire cement bed. A bit of work, but now I can lay cement board on the plywood and I know I will have a smooth surface.

Regards,

Rudy

I think if we knew the new tile was thicker from the start I would have agreed with Glavines approach. He told me how he does a total tear out and it really sounded like it might be quicker/easier than trying to save the bed. I'll try his suggestion on my next foyer job.