: I am doing ceramic on concrete in the basement. The existing toilet is sitting on a 2" high plywood carpeted platform. I'm not sure why this was done even after removing the toilet and inspecting the platform. I would rather not have the toilet sitting on this hollow plywood platform and then on cermaic because I'm afraid the ceramic might break. Can the toilet be mounted on the concrete floor?

There almost certainly has to be a reason for this. The best guess is that the drainage line was too high to be able to get the closet bend in and maintain grade to the main. I wouldn't start taking concrete out without doing some more investigation to try and find out why this was done in the first place--this is not the kind of thing anyone would (probably) do unneccessarily.
Deb
The Pipewench