So long as the existing ceramic tile floor is in good shape (level without major chips and cracks), porcelain tiles can easily go over it. We had that done in our master bath and there have been no issues doing that ever since we did that about five years back. It is just that the floor will be a tiny bit higher and the doors had to be adjusted higher to avoid scrapping the bottom. We are very happy with the installation of porcelain over ceramic tiles in our bathroom and it looks absolutely gorgeous with a minimum of hassle.

So long as the existing ceramic tile floor is in good shape (level without major chips and cracks), porcelain tiles can easily go over it. We had that done in our master bath and there have been no issues ever since we did that about five years ago. The only problems are that the floor was a tiny bit higher, and the doors had to be adjusted higher to avoid scraping the floor. We are very happy with the installation of porcelain over ceramic tiles in our bathroom and it looks absolutely gorgeous with a minimum of hassle.