Replacing One tile -- How?

One tile in the middle of my foyer has cracked. I have some leftover tiles from the construction of the house many years ago. (I am 2nd owner) The tiles were laid over plywood by the builder, My guess is that the tile was never set properly into the thinset, since the tile came up easily and clean.

Do I need to chip out the old thinset? That's what I plan to do, hoping no more tiles come loose in the process.

Would some type of adhesive work if I left the old thinset in place? Is that a safer alternative to pounding on the floor to chip out the old mortar and causing more damage? The old mortar looks intact.

I think this may be "the beginning of the end" for your foyer tile.

It sounds like the problem is your plywood subfloor. Most pro's wont set tile on plywood because it wont stick. The right way to patch the tile would be to chip out the old tile and thin set down to the clean floor. Then re-set the tile using modified thinset. My only worry is that when your chipping the old thin set out your gonna break whatever bond you still have with the other tiles. Then not far down the road they crack up too. Sorry!

Plywood itself isn't the problem, although it may be due to some problems associated with setting over plywood if it's not done correctly.

Regardless, the bottom line is you need to find out WHY that tile cracked (and popped so easily) before you replace it, or you'll most likely be replacing it again.

Let me ask you-- you said this tile was set over plywood-- is there a joint in the plywood under the tile that cracked?

Thanks for the responses and the warnings!

Bill, the basement is finished, so I cannot easily see the underside of the floor at that point. My guess is not, as the thinset itself did not crack. It looks solid and stuck to the plywood below. (but I can only guess)

Some thinsets will withstand a little flex without cracking, tile will not. No cracks in the thinset means nothing maybe.