How to Fix a Wobbly Toilet in 5 Easy Ways

Last Updated on January 13, 2022 by toilethaven

How Do You Steady a Wobbly Toilet?

A wobbly toilet is not only uncomfortable but it could also be a health hazard. Fortunately, fixing a wobbly toilet can be a very easy task, one which you will hardly need to call in a plumber.

If a rocking toilet is left unfixed for a long time, the wax ring seal will eventually be broken due to the sideways movement which will make it start leaking. Your problems will be far from over because if your floor is wooden it will certainly start to rot.

Toilets wobble when they are not firmly secured to the floor. This is caused by loose toilet bolts, a broken toilet flange or even an uneven floor. It could also happen if the toilet flange is too high off the finished floor or if the subfloor is soft/weak.

To steady a wobbly toilet, use toilet shims to level it if it is installed on an uneven floor. Tighten the toilet anchor bolts if they are loose or replace the toilet flange if it is broken. If the problem is caused by a soft/weak subfloor, you will need a flooring specialist to fix it.

There is a difference between a wobbly toilet and a rocking toilet seat. A rocking toilet seat is almost always caused by loose mounting bolts. Check out this post how you can fix it.

A broken toilet wax ring seal will lead to water flooding around the base of the toilet or even a urine/sewer smell inside the bathroom. You might also notice dampness on the ceiling of the basement.

What Causes a Toilet to Wobble?

A wobbly or rocking toilet is caused by either of following:

  • Loose toilet bolts
  • Toilet flange too high off the floor.
  • Broken/corroded toilet flange
  • Soft and weak subfloor
  • Uneven floor

Toilets bolts are the the 2 bolts on each side of the toilet bowl which anchor it on the floor. They are hooked on the toilet flange and tightened using nuts. Sometimes these bolts are covered with bolt caps matching the color of the toilet.

A toilet flange is the pipe fitting which connects the toilet bowl to the drainpipe. Old flanges are made of cast iron but modern ones are made of plastic.

Loose toilet bolts and/or a broken flange are the ones most responsible for a wobbling toilet. Toilet bolts can be easily tightened but a a broken toilet flange will need to be replaced.

A toilet flange should ideally be 1/4 inch above the finished floor. If the toilet is in an uneven floor then toilet shims should be used to level it.

How to Fix a Wobbly Toilet

There are a few ways to fix a wobbly a wobbly toilet depending on what the problem is. To fix a wobbly toilet:

  • Tighten the toilet bolts.
  • Replace the toilet flange.
  • Shim the toilet.
  • Repair and level the floor.

The first thing to do is to ensure the toilet has no leaks. Carefully check the base of the toilet to see if there are any leaks. If there are no leaks, go ahead and inspect the condition of the toilet bolts.

1. Tighten the Toilet Bolts

Check on each side of the toilet to locate this bolts. Usually, the nuts of the bolts are covered with plastic caps that match the color of the toilet, purely for aesthetics. Use a flathead screwdriver to remove the caps. Check using your hand if the bolts are loose or tight. Confirm with a wrench.

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Tighten the bolts if they are loose. If the bolts are more than hand tight, use a pair of pliers or wrench and tighten them a little. Always be careful when tightening the toilet bolts not to crack the bowl.

A broken bowl can be repaired. Also, check out the condition of the washers. Sometimes the washers get deformed, which makes the bolts loose and hence a wobbling/rocking toilet.

If the bolt rotates and does not tighten, grab the top of the bolt with a pair of pliers and tighten the nut using an adjustable wrench.

2. How to Shim a Wobbly Toilet

If even after tightening the toilet it is still wobbling, it is time to shim it. Use some plastic shims and insert them underneath the toilet bowl until the entire toilet is solid on the floor.

Use a knife to trim the protruding ends of the shims. Caulk all around the base of the bowl. Wait for the caulk to dry before using the toilet

In order to install the shims properly, start by loosening the toilet bolts then tighten them once the toilet is no longer wobbling. More information on that in this post.

There are people who do not like to caulk the toilet to the floor. There are actually many reasons why you should caulk your toilet especially after shimming it.

The main concern is aesthetics and also the fact that you might not notice when your toilet starts to leak. This is however not factual.

Read on why I think you should caulk your toilet on the floor on this post.

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3. Replace the Toilet Flange

If you find out that the cause of your wobbling toilet is a broken toilet flange then you will have no option but to replace it.

Replacing a toilet flange will definitely take time but it is totally doable. Bringing in a plumber to replace it for you will cost you way too much and you are better off doing it on your own.

Materials Needed

  • Adjustable wrench/pliers
  • Newspapers
  • Putty knife
  • Rag
  • Sponge
  • Bucket
  • Flange bolts, nuts and washers
  • Toilet shims
  • Caulk
  • A small hacksaw
  • Flange repair kit/new flange
  • Wax ring/ rubber seal

Step 1: Remove the toilet

There are two types of toilets. One-piece toilets and two piece toilets. One piece toilets are made as one unit compromising the bowl and the tank. The two-piece toilets are made with the bowl and tank separate and only joined during installation.

If you have a one-piece toilet, you have no option but to remove it all at once. If instead you have a two-piece toilet, you may opt to remove the tank first then the bowl later. Although this is a long process, it might be the safer one. When you remove them both together, you risk cracking the tank where it is joined to the bowl.

Now proceed to remove the tank as follows:

  • Turn of the water shut off valve. You will find this at the rear wall of the toilet.
  • Flush the toilet and hold the flushing lever down to remove all the water in the tank.
  • Use the sponge to mop out all the water left in the tank and inside the toilet bowl.
  • Disconnect the water supply line from the tank. This is the line that fills the tank with water from the shut off valve.
  • Use the wrench to loosen the two toilet bolts.
  • Once the bolts are out, hold the toilet by the bowl and rock it a little to break the wax ring seal.
  • Once the toilet is free, lift it off and place it on the newspapers.
  • Stuff a rag inside the drain pipe to prevent bad odors from getting into the house.
  • Use the putty knife and scrap off the wax from the toilet outlet and flange.
  • Check if the flange is broken, corroded or just too old.
  • If the flange is defective in any way, go ahead and a and remove it.
  • The flange is screwed to the flooring using screws. Use a screwdriver to remove them.
  • Check out also at the general condition of the subfloor.

Step 2: Replace the Toilet Flange

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If your flange needs repair, use a toilet flange repair kit to perform any repairs needed. There is also the chance that the flange is old and corroded hence unusable. In this case you must replace it. If however the flange is in good condition, you will only need to buy the bolts, washers and nuts. A new wax ring must also be used. A wax ring cannot be reused.

The condition of the subfloor can hold you back for some time. If it is wet, soft or rotten, you should repair it first, before fixing the toilet. A weak floor will always make a toilet to wobble.

Check a detailed article on how to replace a toilet flange here.

Step 3: Replace the Wax Ring

  • Before fixing the wax ring, it is important for you to establish that once the toilet is installed it will not wobble again. You will therefore slot in your two bolts and washers in the flange and install the toilet without the wax ring.
  • If you have replaced the flange, be careful with the positions of the two bolts. Always use the clock rule. Assume the flange is a round clock with the back of your toilet as the 12 noon mark. Make sure your bolts are at the 3 and 9 o’clock marks.  The toilet must always be perpendicular to the rear wall.
  • Once you have your toilet in position, try to rock it about to see if it is flush off the floor or there is a gap. If there are gaps, slide in some shims until the toilet is sitting pretty. Mark the points where you had the shims. Remove the toilet.
  • Lay the toilet on its side and slide in a wax ring on its outlet. This method is better than putting the wax ring on the flange and installing the toilet on top of it. With this method, you are always sure the wax ring will seal. Alternatively, you can decide to use a rubber seal instead of a wax ring. Just put it on top of the flange and install the bowl.

Step 4: Install the Toilet

  • When your wax ring/rubber seal is in place, lift the toilet and align it with the 2 bolts. Slide the bolts through the holes on the toilet base and lay it down gently. Rock the toilet gently to make sure it is solid on the flange and that the wax is sealing.
  • Slide in the shims in the spaces you had marked before. You might need to tap them slightly with a small hammer to make sure they go in as much as possible. Trim the  protruding ends of the shims.
  • Put in a washer and a nut in each of the two flange bolts and tighten alternatingly.  It is exceedingly important to tighten the nuts alternatingly to balance the pressure on both sides of the toilet. If you tighten one side before tightening the other, the toilet will slant to one side. Remember to also not tighten too much as this can crack the toilet bowl.
  • Test the toilet. Sit on the toilet and feel if there is any change. If you are satisfied with the results, then congratulations! You now know how to fix a wobbly toilet.
  • Cut off the ends of the toilet bolts just above the nut and cap them off.
  • Caulk the base of the toilet and wait for it to dry before using the toilet.
  • Reconnect the water supply and enjoy your toilet trips going forward.

Conclusion

Fixing a wobbly toilet can be an easy task or hard task. In the same light, it can be very cheap or very expensive. If you know how to fix a wobbly or rocking toilet, you can massively bring the cost down by avoiding hiring a plumber. A toilets is an essential home appliance that should be comfortable at all times; for you and your guests.

FAQs

1. How do I fix a wobbly toilet seat?

A wobbly toilet seat is caused by loose mounting bolts. Use your left hand to feel the wingnut underneath the toilet bowl. Hold it and tighten the bolt with a screwdriver. If the bolt head is covered with plastic caps use a flathead screwdriver to remove them.

2.Can a loose toilet cause a leak?

A loose toilet if not fixed promptly will surely cause a leak. Continuous rocking will after sometime break the wax seal and flush water will start leaking in to the bathroom floor.

3. How do I fix a wobbly toilet tank?

A toilet tank is fixed on top of the toilet bowl. If it is wobbling, it is because the bolts fixing it on the bowl are loose. The best way to tighten this bolts is by make a ¼ turn on each bolt alternatingly. If you tighten one bolt at a time the pressure will not be evenly distributed and you risk cracking the tank, or the tank will lean to one side. Make sure each bolt has a washer.