How to Fix a Loose or Rocking Toilet

White ceramic toilet in bathroom seen from above

The Spruce / Sarah Lee

Project Overview
  • Working Time: 15 mins
  • Total Time: 8 hrs
  • Skill Level: Beginner
  • Estimated Cost: $8

Rocking is for concerts and chairs—not toilets. If your toilet is wobbly or loose but not leaking, this quick fix might be just what you need. Toilets usually rock because they are not resting flush against the floor. Underneath the toilet base is a round toilet flange that connects the toilet to the drain pipe. If the flange is a little higher than the surrounding flooring, the toilet becomes raised slightly in the center, allowing it to rock to either side.

This problem can develop over time, such as when the wax seal becomes faulty or when a surrounding floor settles a little. Fortunately, there is an easy fix.

Tip

The best shims for this project are small plastic shims with ridges that help the shims stay in place. They are commonly sold at home centers, hardware stores, and restaurant supply stores. Wood shims are not recommended because they can compress over time and are vulnerable to moisture damage.

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Watch Now: How to Fix a Rocking Toilet

What You'll Need

Equipment / Tools

  • Utility knife

Materials

  • Plastic shims
  • Tub and tile caulk (color-matched to your toilet and flooring)
  • Paper towels or rag

Instructions

Materials and tools to fix loose, rocking toilet

The Spruce / Sarah Lee

  1. Check the Bolts First

    Sometimes a rocking toilet can be fixed by tightening the two flange bolts, or closet bolts, at the base of the toilet. Do this carefully. Tightening the bolts too much can crack the brittle porcelain of the toilet, for which there is no repair.

    Check the flange bolt at each side of the toilet, using a pair of pliers or a small wrench. If a bolt is loose, tighten it slowly just until it is snug. Check the other bolt to make sure it is equally snug, then test the toilet for rocking. If it still rocks, proceed with shimming the base.

    Pliers tightening bolts at bottom of white rocking toilet

    The Spruce / Sarah Lee

  2. Look for Leaks

    Confirm that your toilet is not leaking. Check carefully for water around the base of the toilet. If water is not present, you can proceed with the repair. But if there are signs of leaking around the base, it likely means that the wax ring sealing the toilet horn to the toilet flange has become old and compressed. In this case, you must remove the toilet and replace the wax ring.

    Blue cloth soaking up leaks from loose, rocking toilet

    The Spruce / Sarah Lee

  3. Locate the Gaps

    Examine the base of the toilet, and identify any gaps between the toilet and the floor. It may help to rock the toilet from side to side. Even a small space can be the source of the problem. If the gaps are too small to see, try sliding a shim under the base to see how far it goes in.

    Small gap under white ceramic toilet

    The Spruce / Sarah Lee

  4. Insert the Shims

    Level and steady the toilet by inserting shims into any gaps you've identified. You may have to try them in a few different positions to properly level the toilet. As you work, check the toilet for stability by sitting on the seat and rocking in all directions. Repeat until the toilet doesn't move in any direction.

    Shims added in toilet gaps closeup

    The Spruce / Sarah Lee

  5. Trim the Shims

    Trim the shims close to the base of the toilet, as needed, using a sharp utility knife. Be careful not to cut into the flooring.

    Shim being trimmed with utility knife under white toilet

    The Spruce / Sarah Lee

    Tip

    You can add a dab of caulk below the shims to help them stay in place. Let the caulk dry overnight before trimming the shims.

  6. Caulk Around the Base

    Apply a thin, even bead of caulk around the base of the toilet to cover the gap along the floor and hide the shims. If necessary, smooth the caulk with your finger, wiping your finger clean frequently with a paper towel or a rag.

    Tip

    Caulk is important for a finished look and to keep mop water from getting under the toilet base, but if you seal all the way around the base, the caulk can hide a leak by trapping the water. For this reason, some plumbers leave the backside of the base—the side you can't see—without caulk so that leaking water will announce itself by running out onto the floor.

    Caulk added to the base of white toilet

    The Spruce / Sarah Lee

  7. Let the Caulk Dry

    Allow the caulk to cure as directed before using the toilet. Once it dries fully, your toilet should be as good as new.

    Caulk drying around base of white ceramic toilet

    The Spruce / Sarah Lee

If the Toilet Won't Stop Rocking

If tightening the flange bolts or shimming the toilet base doesn't stop your toilet from rocking, there might be more significant problems down below. The flange bolts that secure the toilet base are themselves held by a metal or plastic ring at the top of the toilet flange. The ring can corrode or break, loosening its grip on the bolts.

If your rocking comes back after ​a while, or if the bolts loosen up and won't retighten, a damaged flange is likely the cause. The solution is to remove the toilet and either replace the old flange or repair it with a flange repair kit.