How to Fix a Loose, Rocking Toilet

Bathroom interior
Marlene Ford / Getty Images
  • 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 caulk hardens or when a surrounding floor settles a little. In any case, you can steady the toilet by shimming under its base. But before you try that, make sure the bolts at the base of the toilet are snug.

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.

What You'll Need

Equipment / Tools

  • Utility knife


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


  1. Check the Bolts First

    Sometimes a rocking toilet can be fixed by tightening the two bolts at the base of the toilet, called flange bolts or closet bolts. 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.

    Man's hand pointing to toilet bolts at the base of the unit.
    Stack Exchange
  2. Look for Leaks

    Start the repair by confirming 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.

    Man using a yellow sponge around the base of the toilet.
    Aaron Stickley
  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.

    Man locating gaps between the toilet and floor and using plastic shims.
    Aaron Stickley
  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.

    Two plastic shims inserted into the base of the toilet.
    Aaron Stickley
  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.

    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.

    Person using the utility knife to trim the plastic shim placed at the base of the toilet.
    Aaron Stickley
  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.

    Caulk is important for a finished look and to keep mop water and crud 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.

    Man caulking around the base of the toilet.
    Aaron Stickley
  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.

    Completed caulk bead around the base of a toilet.
    Aaron Stickley

If the Toilet Won't Stop Rockin'

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.