Mike's Bathroom floor project

[mevans0430]

First time tiling, I'm using 12 X 12 ceramic tiles on the floor. Cement board underlayment is down, I've dry fitted the tiles with spacers, but some of the tiles aren't quite flat on the floor, they wobble a little.
Can I mix the thinset mortar a little thicker and use it to make all tiles sit level and flat?

 

[Hobnob]

Yes, lift the tiles and bed a little more adhesive under, until you get all corners sitting flush.

 

[Michael f]

Thanks so much for the reply.
Will follow your advice.