Got a little tiling question I hope you can help with.

Check the thinset instructions for surface prep.

If it has a problem adhering to sealed concrete, I think you could either strip the sealer or rough up the surface with some coarse sandpaper to improve the adhesion.

Maybe try a bit of thinset in an out of sight location ( under the sink? ) to see how well it will stick do the sealed concrete.

If you have the time the best answer would be to do a test section and see how it bonds. What thinset are you using.

A good polymer modified thinset will stick just fine. If you are really concerned, paint on a layer of concrete bonding compound or use latex admix in the thinset (see bag instructions, more expensive thinset already has it inside). BigBox has about 5 or 6 kinds in the store, you want the third down from the most expensive (unless you want white)

I used this method on painted concrete with no problems yet.

If the sealer is more like a thick coat of polyurethane which can peel up on its own, you will want to strip it or score it to expose much of the underlying concrete. Sanding with a concrete brick works well in this situation.

A good polymer modified thinset will stick just fine. If you are really concerned, paint on a layer of concrete bonding compound or use latex admix in the thinset (see bag instructions, more expensive thinset already has it inside). BigBox has about 5 or 6 kinds in the store, you want the third down from the most expensive (unless you want white)

I used this method on painted concrete with no problems yet.

try pro red