Do You Need to Level a Toilet Tank? The Complete Step-by-Step Guide

Is your toilet rocking, leaking, or just not flushing right lately? There‘s a good chance it needs to be leveled. Toilet tanks can become unleveled over time due to shifting floors, improper installation, or everyday use. But not to worry – leveling a wobbly toilet tank is usually a quick and straightforward DIY project.

In this detailed guide, we’ll walk through everything you need to know to get your toilet tank sitting evenly, from how to spot leveling issues to step-by-step instructions for simple fixes. With the right information and a little elbow grease, you can solve most unleveled toilet tanks in no time. So let’s get into it!

Why Leveling Your Toilet Tank Matters

Before we dig into the how-to, let‘s look at why a properly leveled toilet tank is so important for keeping your bathroom functioning smoothly.

• According to hardware store surveys, approximately 15% of homeowners report issues with rocking or unleveled toilet tanks.
• An unleveled toilet tank can allow water to escape and leak onto the bathroom floor, causing potential water damage and growth of mold or mildew.
• Wobbling tanks put added stress on the bolts and porcelain, which can lead to cracking and the need for expensive repairs or replacement.
• Tanks that rock back and forth also make loud, annoying noises whenever someone sits on the toilet.
• Unleveled tanks can result in uneven flushing power, incomplete draining, and eventual toilet clogs.

For optimal performance, lower repair bills, and greater peace of mind, keeping your toilet tank properly leveled is a must.

Identifying Toilet Tank Leveling Issues

Before you can fix a problem, you need to accurately diagnose it. Here are some of the most common signs that your toilet tank needs to be leveled:

1. Rocking or Unsteadiness

If your toilet tank rocks, shifts, or feels wobbly when you press down on the seat, the tank is likely unleveled.

2. Water Leaking from Base

Check around the base of the toilet for any evidence of moisture or pooling water. A damaged wax ring from an unleveled tank is the probable culprit.

3. Tank Makes Noise When You Sit Down

Loud creaking or rocking noises from the tank as you sit means it’s loose and needs to be stabilized.

4. Uneven Flush Performance

Poor flushing can signal that the tank isn’t securely seated to direct water flow properly.

5. Bowl Seems Loose on Floor

If the entire toilet wiggles, the wax ring seal connecting it to the floor flange may be compromised by an unlevel tank.

6. Visible Gap Between Tank and Bowl

A gap where the tank and bowl meet could indicate loosening of the mounting bolts caused by rocking.

If you notice any of these signs, it’s definitely time to inspect the level and make needed adjustments. Catching and fixing small leveling issues quickly can prevent more severe toilet damage down the road.

Checking If Your Toilet Tank is Level

Before taking out your toolbox, it’s important to accurately diagnose whether your toilet tank needs leveling or if the issue lies elsewhere. Use these steps to check:

What You‘ll Need

• 4" bubble level
• Flashlight (optional)

Step-by-Step

1. Place the level vertically against one side of the tank near the base.
2. Position the level until the bubble is perfectly centered between the indicator lines.
3. Move the level to each adjacent side and top of the tank, repeating steps 1-2.
4. Carefully check the bubble each time to see if it’s centered or off.
5. Use a flashlight to illuminate the vial if needed.
6. If the bubble is off-center on any side, your tank needs leveling.

Checking toilet tank level with a 4" bubble level. Image source

This quick test will confirm whether or not your toilet tank is properly leveled before you begin any repairs.

How to Level a Toilet Tank Using Shims

One easy and inexpensive way to level a toilet tank is by using shims. Let’s look at how to shim a toilet tank in just a few simple steps:

What You‘ll Need

• Shims (plastic or wood, 1/8" – 1/4" thickness)
• Putty knife

Step-by-Step

1. Buy shims of varying thickness like 1/8”, 1/4", etc. I recommend plastic multi-height shims from Home Depot.
2. Loosen the tank bolts using a wrench but do not detach tank.
3. Determine where the tank needs shimming by checking the level.
4. Insert shims underneath tank feet or anchors on the low side.
5. Re-tighten bolts and check level. Add or remove shims as needed.
6. Once level, secure shims by applying Loctite construction adhesive.
7. Let adhesive fully cure for 24-48 hours before stressing the toilet.

Shimming is an easy, inexpensive way to level a toilet tank. Just be sure to use proper shim materials and allow time for adhesives to fully set before using the toilet.

Shimming underneath the toilet tank base or anchor points levels the tank. Image source

Adjusting Toilet Tank Bolts to Alter Level

If your toilet uses a tank that isn’t removable from the bowl, adjusting the tank bolts is another handy way to tweak the level.

What You‘ll Need

• Adjustable wrench
• Groove joint pliers (optional)

Step-by-Step

1. Turn off toilet water supply and flush to empty tank.
2. Use a wrench to loosen the nuts on the tank bolts below the tank.
3. For the higher side of the tank, tighten nut below tank to raise that side.
4. On the lower side, loosen nut to lower tank. Make adjustments gradually.
5. Use groove joint pliers to grip bolts if nuts are stuck.
6. Check level frequently and re-tighten nuts once tank is level.
7. Turn on water, refill tank, and check for leaks.

Loosening one side while tightening the other allows you to gradually alter the level. Just take it slowly and check your work often.

Dealing With a Severely Unleveled Floor

Sometimes the real issue is that the floor itself is uneven, making it nearly impossible to level the tank. If shims and bolt adjustments aren’t doing the trick, here are a few other options:

• Use an extra-thick wax ring or flexible rubber gasket to seal the uneven gap beneath tank.
• For vinyl floors, shim under the floor before setting tank to create a level surface.
• Apply self-leveling floor compound around the flange to even out the surface before resetting tank.
• Replace with a floor-mounted, one-piece elongated toilet designed for unlevel floors.

In extreme cases of uneven floors, replacing the entire toilet may be the only path forward. Bring in a plumber to advise.

Troubleshooting Tricky Toilet Tank Leveling Issues

Sometimes toilet tanks can be tricky to level properly, even after multiple attempts. Here are some steps to try:

• Double check that closet flange is evenly secured to floor and not damaged.
• Try a different thickness of wax ring seal to improve the fit.
• Use groove joint pliers for better grip and torque on stuck bolts.
• Replace misshapen plastic tank washers contributing to unevenness.
• Have helper hold tank steady as you adjust bolts and shims.
• Confirm shims are placed appropriately underneath lowest tank points.
• Loosen bolts completely and reset tank to get a fresh start.

Taking the time to troubleshoot will help you pinpoint and address the specific issue keeping your tank unleveled.

Preventing Future Toilet Tank Leveling Problems

A little preventive maintenance goes a long way for keeping your tank securely leveled for the long run:

• Inspect the level a few times per year and re-adjust as needed.
• Make sure tank bolts remain tightened. Replace washers if bolts become loose.
• Confirm floor around the flange is sound and level. Address any issues.
• Consider upgrading to a one-piece, floor-mount toilet that requires less leveling.
• Use quality shims and flexible wax ring seals that won’t compress or crumble over time.

With occasional checkups and using quality hardware, you can avoid constant toilet rocking headaches.

When It‘s Time to Call a Professional for Toilet Replacement

While many toilet tanks can be leveled successfully at home, some issues do require calling in a pro:

• The floor is badly sloped or damaged and cannot be leveled.
• The tank or bowl is cracked, warped, or otherwise defective.
• The wax ring seal is damaged beyond repair.
• The closet floor flange is corroded or broken.
• There are signs of a collapsed or blocked drain line below floor.

For major underlying problems like these, a full professional toilet replacement is likely the wisest and most effective solution. An experienced plumber can remove your old toilet, assess any drain or sewer issues, and ensure the new toilet is properly leveled and functioning optimally.

Key Tips for DIY Toilet Tank Leveling

Before you get started on this toilet repair project, keep these safety tips in mind:

• Always wear gloves and eye protection when working on a toilet.
• Turn off the toilet‘s water supply valve and flush out all water from the tank beforehand.
• Make gradual adjustments and frequently check for level to get it right.
• Do not use metal shims, as they can corrode and cause rust stains.
• Make sure any adhesives have fully cured before using the newly leveled toilet.
• Seek professional help if you‘re unable to successfully level the tank after multiple attempts.

And those are the basics of leveling a toilet tank! With this detailed guide, you now have all the information needed to spot potential issues, check for level, and make DIY adjustments to get your toilet tank seated evenly. Just remember to work carefully, take your time, and don‘t be afraid to call a plumber for any severely unleveled or unstable toilet tanks. Happy leveling!