I am in the process of replacing the vinyl on my bathroom floor with ceramic tiles. I have removed the toilet from it’s base flange. The sub-floor being wood, I had to screw a 1/4″ cement board over it. On top of this will come the 1/4″ thin-set mortat and then the ceramic tile.

My question is: Now that the new ceramic tiled floor is going to be about 3/4″ higher than the old vinyl floor, how do I put the toilet back? ie. there will be a difference in height between the toilet and it’s base flange which may be more than what the wax ring can seal? Should I use flange extenders & if so how to you set them onto the old flange? Or can a “double” wax ring solve the problem?