Resetting a Toilet When You Change Your Flooring

Scott Gibson, Contributing Editor

I have a new tile floor down in my bathroom which has left the closet flange below floor height. I am planning to use a new wax ring and bolts but I'm not sure whether I need to raise the flange or if the wax ring would make up the difference. The floor is now about one-half to three-quarters of an inch higher than it was.

The short answer is to buy an extender kit for the closet flange. Extenders are simply rings that can be stacked on top of the flange to raise the height. That ensures a reliable seal between the base of the toilet and the flange. Kits are inexpensive and should be available at just about any plumbing supply house or big box store.

Flange sits on top of the finished floor

For those of us who aren't up to our elbows in a toilet rehab it might be useful to look at how a toilet should be set. In new construction, the plumber roughs in the soil pipe to the floor of the bathroom where the toilet eventually will be placed.

After the builder has installed the finished floor, the plumber (in this case, you) returns to complete the job. The next step is putting on a closet flange. One end fits over the soil pipe and is glued in place, assuming your house is plumbed with PVC. The other end of the flange is a metal or plastic collar that sits on top of the finished floor.

The flange is secured to the floor with stainless steel screws long enough to bite into the subflooring.

Closet bolts--typically one on each side--are inserted into the closet flange. Next comes a wax ring, which can be pressed onto the bottom of the toilet or on top of the flange, and then the toilet bowl itself.

The right height is important

If the top of the closet flange is too low, a common problem when a new layer of flooring is added, the wax ring will not be able to provide a good seal.

This is important because the ring prevents sewer gases from getting into the house. (I know this because I omitted the wax ring the first time I set a toilet. I didn't know they existed. We lived with an unpleasant odor in the bathroom for months before someone finally straightened me out.)

When the toilet is set on top of the flange, it should settle down until it rests on the floor, compressing the wax as it goes. Gently tightening the nuts on the closet bolts locks the whole assembly together.

An extender (or possibly two) will bring the height of the flange back to where it should be. A kit may include two extenders of different thicknesses. They can be stacked together. A bead of silicone caulk will seal them together and to the top of the original flange.

A flange that's too high won't allow the toilet to sit firmly on the floor. So if you get the flange even with the finished floor, the wax ring will be able to take up any slack.

When you're finished, the toilet won't rock and your installation should be leak (and odor) free.

About the Author
An accomplished woodworker and carpenter, Scott Gibson is the former editor of Fine Woodworking magazine, and a former editor at Today's Homeowner and Fine Homebuilding magazines. He also is former managing editor of the Kennebec Journal, a daily newspaper in Maine.

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