: I have installed a tile floor in a basement bathroom and when I place the toilet base down on the finished floor it rocks slightly. In the front of the toilet there is about a 1/8 of an inch "dip" which I can see by the gap between the toilet and the floor. Is there a way to shim under the toilet? What should I use as a shim? Should I rip up the tiles and try again?
I recently had the exact same problem after installing a new floor. There was just the slightest dip near the front of the toilet and I had the same slight rocking. To fix it, I simply took a wood shim and slid it under the front of the toilet base until it was tight and the toilet was leveled. Then I scored the shim 3 or 4 times in the same place with a utility knife as close as I could to the toilet base and then snapped the rest off by prying it (the shim) up gently. Toilet doesn't rock anymore and you can't see the shim (short of getting on the floor and looking for it).
Maybe a licensed plumber has an opinion to the contrary, but for such a small gap I can't imagine you should have to redo the floor.