Ceramic tile install over a sealed concrete floor?

[Alex]

Hi all -

Getting ready for a ceramic tile install this weekend in my basement & ran into a possible last minute "uh-oh"

...I'm installing 13x13 tile using VersaBond thinset from Lowes over part of the concrete slab in my basement. Someone just mentioned to me that it can't be installed over a sealed concrete floor.

I _think_, but am not entirely sure that the floor was sealed after it was poured around 10 years ago. On the VersaBond bag it does say to remove sealant before applying.

I did a test with some water on various parts of the area I'm going to install the tile. When I poured the water onto the concrete it did pool a little... but after it either all soaked in (for smaller pours) or I wiped it up (on the larger pours), it did leave the concrete a wet color. Some of the dark areas were uniform in color, others had a snakeskin sort of pattern going on.

Will I be ok putting down the thinset as long as liquid does absorb into the floor - and leave it discolored - basically leaves a 'wet spot'?

Thanks!

[Ken]

Installing ceramic tile is not cheap. Do it the correct way. If you do not and it fails to adhere to the floor, you have one expensive mess.

On the other hand, if you do it right it will last for years and you will be glad you installed it.

[Alex]

Trying to! That's why I asked the question... thanks...

If water soaks into the floor and leaves it discolored - rather than beading and staying on top does that mean I'm getting enough penetration for the thinset?

[dadiOH]

Yes.

[valvejob]

It is practically impossible to screw up when installing ceramic tile on concrete.

Even if it is sealed, you just have to let it dry longer before walking on it. Might take 2 weeks to set firmly so spend a few extra minutes and remove the seal best you can.

[Mikepier]

I've installed tile over concrete before and never had problems. As long as the basement floor is not painted or at the very least the surface "roughed up" a little, the thinset will adhere with no problem.

[Andrew Sarangan]

Can you run a floor sander to roughen up the surface? That's what I did on my garage floor before installing an epoxy coating. I could not positively verify whether it was sealed or not. It took just 15 minutes using a rented floor sander.