How to Level a Toilet With Shims

Lower the toilet slowly over the flange and wax ring, setting the toilet down gently so you do not damage it or the flange. Thread the closet bolts through the holes in the base of the toilet as you lower it over the flange.

Sit on the toilet bowl without twisting it, compressing the wax ring so the base of the bowl sits firmly against the floor. Slide the washers over the bolts and tighten the nuts onto the washers using a wrench, turning the nuts until you feel resistance from them. Do not overtighten the nuts or you risk cracking the porcelain.

Insert plastic shims into any gaps between the toilet’s base and the floor, pushing the shims as far as possible under the toilet until they stop. Place a level on the toilet to verify that it is level and adjust the shims as necessary. Press down hard on a utility knife’s blade as you drag it along the shim where it meets the edge of the toilet’s base, trimming the shim so it does not stick out from the toilet.

Place a sharp wood chisel on the shims where they meet the edge of the toilet’s base, if the utility knife did not cut through the shims. Strike the other end of the shims with a hammer hard enough to cut through the shims without damaging the bathroom floor.