What Causes a Toilet to Rock and How to Fix a Loose or Wobbly Toilet

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If you have a shaky toilet, it cannot be very pleasant. In this article, we will be learning how to fix a loose toilet and what causes it to rock.

Sitting on a loose toilet can be uncomfortable, and it most likely means there are problems with your toilet, such as a cracked flange, broken wax seal causing water leaks, and bad smells from the cracked seals that can make every trip to the bathroom an unpleasant one.

However, before you reach for the phone to call a professional, here are a few DIY tips on how you can deal with a toilet that wobbles when seated on. We will also look at what tools you will need to get the job done.

But first, let’s understand how the toilet works.

Inner Workings of a Toilet

Swiss Madison SM-1T123 Virage One Piece Elongated Toilet 1.28 GPF

Almost all toilets are constructed and installed in a similar fashion. The toilet base is connected to a flange that is fixed to the floor, which is, in turn, connected to the drainpipe leading to the sewer system. Typically, a rubber or wax ring sits between the base of the toilet and the flange creating a seal preventing any water or bad odors from coming through. 

You have a basic understanding of the anatomy of the toilet now, and it’s time to highlight the main causes of a loose or rocking toilet.

What Can Cause a Toilet to Rock From Side to Side

If your toilet rocks or wobbles, it is an indication that the toilet is not flush with the floor. If you don’t fix this, you might see water leaking near the toilet or experience some bad smells.

There are several things that can make a toilet rock, and each one needs a different fix. Let’s look at why your toilet rocks and what you can do to fix it.

Broken or Loose Closet Bolt Makes Toilet Wobble

One of the first things to check on a moving toilet is loose toilet mounting bolts. If your toilet is loose, it might be because the bolts that hold it in place need to be secured. To fix this, take off the small caps that are hiding the two bolts on the bottom of the toilet.

You will see a nut that should not move when you touch it. If it does move, tighten it down with a socket wrench. Don’t make it too tight, or you might crack the material your toilet is made from. If the bolts are actually broken, you will need to replace them.

Broken Toilet Flange Causing Toilet to Rock

If your toilet wobbles, it might be because the bolts are no longer secured to the flange. Contrary to popular belief, the bolts are not drilled into the floor. Instead, a flange under the base of the toilet is responsible for holding these bolts in place.

The flange is secured to the floor with screws, and a gasket within the flange expands to hold onto the drain, creating a tight seal. It is important to note that if the flange is damaged, then it will have to be replaced.

Damaged Wax Seal

Over time the wax seal which sits below your toilet can crack or flatten. This can be one of the causes for the toilet to wobble. If you see a waxy leak around the base of the toilet, then this may be a clear sign that this is your problem.

In order to resolve this issue, the wax seal will need to be replaced. 

  • Remove the toilet by undoing the bolts and lifting the toilet off, and placing it to one side.
  • The wax seal will have to be cleaned off the flange. If you have a steamer, then that will work; otherwise, pouring boiling hot water over the wax and scraping it up will suffice.
  • Place the new seal and place your toilet back on top, ensuring that it is sitting flush to the floor, creating a good seal between the toilet base and the flange.

How to Fix a Rocking Toilet on an Uneven Floor

1. Finding the Gaps

If the toilet is not sitting flush to the floor and has space between the floor and the base, this could cause the toilet to rock in place. You may not be able to spot the gap so try to insert shims in different places to get a gauge of the space.

2. Leveling the Toilet

Put the shims into spaces you’ve found to level the toilet and stop it from moving. It is a good idea to put the shims around the toilet to make sure it is steady. Once you are done, sit on the toilet and check that it doesn’t move.

3. Clean the Shims

You’ll need to cut the edges of the shims that are sticking out with a sharp knife. Take care not to cut yourself or the floor below.

4. Caulking the Base

Once you’ve trimmed the shims, there will be a small gap that will need to be covered with caulk. Take a small amount of caulk in your hand and gently push a long strip along the space covering the gap.

5. Let the Caulk Dry

Give the caulk time to dry; otherwise, it will leave crack marks. Once it is fully dry, your toilet is ready to use.

Fix Broken Toilet Flange

Oatey GIDDS-173390 43539 Replacement Flange Forcast Iron, 4 Inch, PVC

1. Empty the Water in the Toilet

Emptying the water in the toilet should be your first port of call. Locate the stop valve and the water off. Flush the toilet draining the tank.

Use a sponge or towel and wipe the leftover in the tank. You will have to remove the water supply using a pair of pliers or a wrench.

2. Take Off the Toilet

To lift the toilet, you first need to take the caps off before removing the hex nuts.

Put a dirty blanket or flat piece of cardboard down to place the toilet on as the base may be full grim.

There should be a wax ring on the base of the toilet, which is responsible for stopping dirt and water from leaking out. Stuff a newspaper or old cloth to stop the septic smells from coming up through the open drain hole.

3. Fixing the Closet Flange

If your closet flange is loose then there are a couple of ways to address this.
Naturally, a severely damaged flange will need to be replaced. If however, the damage is nominal, you can simply attach a new repair plate to the existing one. Use a flat-head screwdriver to help fit the plate in below the groove that is there and tighten the nut. This will allow you to secure the flange when reattaching the toilet.

4. Changing a Closet Flange

When removing cast iron flanges, try not to damage or crack the pipe. Separate the closet flange from its position by first unscrewing the bolts that are holding it in place and then wedge a screwdriver or something sharp and pull it off. 

Now is the time to fit your new flange attaching it to the iron pipe that is sticking out of the floor. You may need to cut a bit of the pipe and remove some tiles if the new flange doesn’t fit flush on the floor. 

Once the area is clean, place the flange over the pipe and secure it to the floor with the screws. There is a rubber gasket on the shaft of the flange, when you tighten the screws that sit inside the flange the rubber gasket expands and creates a tight seal in between the pipe and the flange.

5. Reinstall the Toilet

Replace the old bolts with new ones as they may have lost their integrity. Tighten the new bolts in the provided holes on the flange to position the toilet. Place the new wax ring in the center which will create a seal between the base of the toilet and the secured flange.

Place the washers on the bolts and carefully lift the toilet and thread the bolts sticking out of the flange through the holes on the base of the toilet. Put the nuts on and tighten them, securing the toilet to the flange and the floor.
Check nothing is moving or out of place and then finally place the bolt caps on top.

Should I Caulk Around the Toilet?

Yes, it’s definitely a good idea to caulk around the toilet.

Caulk is helpful because it: 

  • Prevents your bathroom from smelling bad 
  • Keeps ants and other creepy crawlies from coming through

Poorly Installed Toilet Can Cause them to Wiggle

If your toilet is loose, it might be because the way it was installed last time was not done well. If you had your floor replaced, then the person who reinstalled your toilet may have done it incorrectly. If you suspect this to be the case, then check to see if they raised the toilet up by putting something under it and making it move.

If you think this is too difficult, you can get a professional to come in. But it’s good to know at least some basics about plumbing before you do that. That way, when it comes time for the plumber to tell you the problem, you’ll have a better understanding. 

Are Rubber Toilet Seals Better Than Wax?

There are two types of toilet seals- wax and rubber. Both seals are meant to stop the toilet from any leaking, but rubber seals that are not compromised can be reused. If you have underfloor heating in your bathroom, then it may be important to note that the wax seal will melt and eventually, the seal will break.

Essential Tools And Materials For Fixing A Wobbly Toilet

Tools and materials required to fix a wobbly toilet. Make sure you have them before you start.

Some tools you might need for fixing a toilet are: 

IRWIN VISE-GRIP Long Nose Pliers, 6-Inch (2078216)

a small wrench or pliers

3Pcs Kitchen Sponge Bathtub Pool Scrub Brush Strong Scouring Dish Washing Cleaning Brush

a vacuum cleaner or bowl and sponge for cleaning

Warner 1-1/4" DIY Stiff Putty Knife, 180

a putty knife

TenkBuff Adjustable Hacksaw Frame Set, 12 Inch Heavy Duty Hand Saw with 10 Extra Blades, Two Sawing Angles(45°/90°) for Sawing Wood, PVC Pipes, Steel Pipes, Frozen Meat (Upgrade, Yellow)

a grinder or hacksaw

Amazon Basics 9-Inch Magnetic Torpedo Level and Ruler, 180/90/45-Degree Bubbles

spirit level

11 Pieces Toilet Wax Ring Kit Include Closet Bolts, Bolt Caps, Thick Flange and Retainer Washers, Fits 3 Inch and 4 Inch Waste Lines for Toilet Gas Odor and Watertight Sealing Supplies

bolt caps, closet bolt caps, washers, new wax ring or old one if it’s not visibly damaged

Qualihome Nylon Plastic Shims for Leveling - Clear Plastic Wedges for Home Furniture, Toilet, Bed, Restaurant Table Wedges - Non Slip Levelers, Stabilizers with Ribbed Design - 8-Pack, 1-1/8" x 2"

shims made of plastic material

Gorilla Waterproof Caulk & Seal 100% Silicone Sealant, 10oz Cartridge, White (Pack of 1)


FAQs Frequently Asked Questions

How much does it cost to replace a toilet?

There are a number of factors that will determine the cost. The cost of the toilet will be the largest cost and then you will need to decide whether you want to fit it yourself or get a plumber to do the job. 

Plumbers are not cheap and can charge anything from $300 – $500 for a toilet replacement which involves them not only installing the new toilet but they will take the old one away.

Why are some toilets more expensive than others?

Toilets are like anything else that you can buy. There are different styles and materials, and even the inner workings can be different, from your basic flushing mechanism using a handle to an electronic flush activated by a remote control or a phone app. The cost can go into thousands if you are not careful, so beware when choosing the toilet.

Can plunging a toilet damage the wax ring?

If you are using too much force when plunging, this can cause the toilet to move and break the seal it has with the wax on the base.

Make sure not to plunge like the world is coming to an end. When plunging, we recommend placing one foot lightly on the toilet so that the toilet doesn’t move violently.

Are wax rings better than rubber?

The rubber seals are relatively new and do a great job of creating a seal. They also do not create any mess, and when changing is required, you simply lift the old rubber ring and replace it with a new one.

That being said, if the floor isn’t smooth and there are divots and small cracks in the floor, then a wax seal would be best, as the wax will fill these small holes and stop any insects or smell from entering your bathroom. 

Can I just silicone a toilet to the floor?

The short answer is yes. The problem is that the silicone will stick to the base of the toilet, and once it needs replacing and it will then you will need to fight with that toilet to remove it, and then you will have the added job of scraping the silicone off the floor and the base of the toilet.

Why is the caulk around my toilet Brown?

This is actually a great way to tell that your wax seal is compromised and needs replacing. This may precede the toilet from rocking, so it’s the perfect time to replace the wax seal and avoid that experience altogether.

Can I use 2 wax rings on my toilet?

Using two wax rings is actually quite common when the bathroom has thick tile floors because the toilet sits higher off the floor than it should. The extra wax ring will ensure a seal and stop any sewer smells from entering the bathroom. 

How long do toilet wax rings last?

Once installed, these wax seals last around 25 years. However, if you have underfloor heating or if it gets extremely cold in your bathroom for whatever reason, then the wax can melt or crack, losing its ability to keep that tight seal, in which case it will need to be replaced. 

Wrap Up

A rocking toilet is a sign that something is wrong. It might mean that the flange or seal is damaged, the bolts are loose, or the floorboard is warped. If you don’t fix it, it will get worse. The rocking motion can crack the flange or the drain pipe. So it’s better to fix it while it’s still a small problem.

If your toilet wobbles, you can fix it easily. You will need the right tools and to follow instructions carefully. If you get stuck, it is okay to ask for help from a professional.

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