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How to Repair a Cracked Toilet Tank? 4 Easy Steps

A toilet tank is built to resist as much water pressure as feasible. Despite our best attempts to prevent it from cracking, the fact is that fractures do form over time, especially hairline cracks in the glazing.

The most important thing to remember is to act quickly when something happens. 

How to Repair a Cracked Toilet Tank

Cracks in toilets are common. There’s no need to be concerned if your toilet has suddenly cracked, this happens all the time. There are inexpensive ways to have it repaired.

When attempting to replace the toilet tank cap/lid, many individuals break their toilet tank. The lid of the tank is quite heavy, and it periodically hits the toilet tank, causing this to happen. The toilet tank is more delicate than the lid, it will simply fracture.

On the other hand, there are times when things go wrong and your toilet tank cracks. For example, you may have spilled a large object on the tank or misplaced the lid while attempting to replace it.

This is a rather common occurrence, and fortunately, one that may be resolved without the assistance of a specialist. While it’s usually ideal to contact a plumber for assistance, you may save a lot of money and time by repairing problems yourself.

When your toilet tank cracks, this article will show you how to fix it.

When the tank breaks, it may begin to leak water. However, it is dependent on the severity of the crack.

A little fracture may not cause your tank to leak, but a significant crack (such as one produced by a heavy item falling on the tank) may cause it to leak.

Cracks that are severe enough to allow water to leak should be repaired right away. The last thing you want to do is have your toilet replaced because that would be far more expensive than fixing a damaged tank.

When you live with a large group of people, it’s much worse since one faulty toilet might signal disaster for the entire home.

How to Fix a Cracked Tank?

How to Fix a Cracked Toilet Tank

1. Turn Off the Water and Dry the Tank on the Inside

Although one may skip this step if there is no evidence of water leaking, it is still a good idea to turn off the water. This also applies to any toilet repairs you may be performing.

Shutting off the water supply is a good idea since the last thing you want is water shooting all over the place and causing a mess.

Water will flow from a damaged tank and spread across the floor. So, if you don’t turn off the water before working on your tank, you might wind up with even more problems than you started with.

It also doesn’t take long to switch off the water. To repair the fractures in your tank, you’ll need to use a sealer, which won’t dry if the region is damp.

Hence, you should make certain that it is completely dry. The last thing you want is for all of your hard work to be for naught because the sealer failed to dry.

Any absorbent material, such as chamois cloth, sponges, or towels, can be used. Wipe off the exterior of the tank as well to ensure that condensation does not form.

2. To Repair a Cracked Region, Use Silicone Plumbing Epoxy

An epoxy sealer is easy to get by at a Home Depot. If it isn’t an option, any porcelain sealer will suffice. Solicit advice from a plumbing professional on the best brand to use for the greatest outcomes.

Depending on the type of sealer available, you may require a caulking gun. If you’re using a gun, fill it halfway with sealant before starting to fill the cracks.

Starting an inch above the crack and working your way down to fill the crack with sealant is the best way to proceed.

3. Smooth Out the Sealer and Allow the Silicon Epoxy to Dry

Distribute the sealer over the crack with a paper knife, a putty knife, or any other instrument that can spread it.

This keeps the toilet looking beautiful even after you’ve filled up the cracks. Spreading the sealer also prevents cracking in other locations.

Allow for at least 24 hours for the coating to dry completely and seal the cracks. However, you may keep an eye on the places you sealed on a regular basis to check how they’re doing.

This also aids in the detection of further glazing fractures. If you haven’t seen any new fractures since applying epoxy, you can begin filling your tank with water.

4. Refill the Tank with Water

Reconnect the water supply to the tank and turn it back on. Check to see if any leaks remain after the tank has been filled with water.

If you still discover leaks, empty the water from the tank and inspect the mended areas again. Alternatively, check to see if you’ve missed any additional locations.

Toilet tanks are constructed with endurance and quality in mind, but this does not guarantee that they will last indefinitely.

Time will eventually win out, and all we have to do now is act to prevent the situation from worsening.

After allowing the epoxy putty to set fully, reopen the shut-off valve and refill the toilet with water. Flush your toilet when it has been refilled and look for any visible leaks.

If there aren’t any, the repair was successful. If the problem persists, look for any other cracks in the toilet bowl, both exterior, and interior, that might be the source of the problem.

If you are unable to discover another damaged place and the problem remains, it may be necessary to seek the assistance of a plumber.

Also Read: Is your toilet clogged

How do I Know if My Tank is Cracked?

A toilet tank might have fractures on the interior or outside, either above or below the water level. The location of the fracture will indicate what intervention is required.

Unless the split spreads slowly, a crack above the water level is typically not an issue. Keep a watch on any toilet cracks in the tank to make sure they don’t become any worse.

Taking a photo of the crack for later reference is a good idea.

It will be necessary to repair a break that is below the water level. A toilet tank fracture, however, might be difficult to detect.

Start by inspecting the seals between the tank and the bowl if you suspect a toilet tank leak.

Next, look for a fracture in the porcelain in the tank. It’s possible that you’ll have to look both outside and inside the tank to find it.

How to Repair a Hairline Crack?

For a DIY hairline repair, we recommend using a plumber’s putty or a watertight silicone epoxy sealer.

How to Repair a Hairline Crack?

Although a caulking gun is not necessary, a knife will be needed to fill and smooth out the substance.

Here’s how to do a do-it-yourself repair:

  1. The toilet tank should be drained. The water in the tank may be removed by turning off the water and flushing it down. The sealant does not dry out because of the water.
  2. Using a towel or a cloth, dry the tank. To avoid condensation, we recommend cleaning off the outside of the tank.
  3. Putty or epoxy should be used to fill the fracture. Smooth the surface of the toilet tank with the putty knife.
  4. Allow at least 24 hours for the epoxy to cure. Because it dries faster, the plumber’s putty is more generous.
    It never entirely dries out, making it difficult to tell whether it’s safe to use the toilet again.
    Check the sealant’s instructions for the recommended waiting period.
  5. Make that the epoxy and the tank are both free of fractures. If the epoxy fractures, seal it even more.
  6. Fill the tank back up with water. Restoring the water supply and inspecting for leaks is a guaranteed approach to ensure that the repair is completed successfully.
    Keep a supply of towels on hand in case something goes wrong.

The safest solution for bigger cracks that are leaking significantly is to replace the complete toilet tank. To examine the damage and replace the tank, it’s better to employ a specialist.


1. When a toilet tank breaks, what causes it to do so?

Temperatures that are too hot or too cold. A toilet can also fracture due to a rapid shift in temperature.

Pouring extremely hot water into the toilet tank might cause the material to shatter as a result of the shock.

If the water in the toilet’s bowl or tank freezes, the toilet and any pipes attached to it may fracture.

2. Is it possible to use a flex seal on a toilet tank?

It can not only prevent leaks, but it can also improve the appearance of your tub, shower, and the regions surrounding your toilet.

Fortunately, we can assist in making the work a bit simpler. Flex Shot is simple to use and does not require the use of a caulk gun.

It also creates a rubber-like seal that keeps water out.

3. Is toilet tank cracking a regular occurrence?

What causes fractures in toilet tanks? Impact, aging, and accidents are the most typical causes of hairline cracks.

While tanks are typically strong, a collision with a large item or a person might result in a minor hairline crack that grows over time.

Wrapping Up

Fixing cracks in the toilet is a straightforward task, despite the fact that it may appear to be the end of the line. Some cracks, though, are too deep to be sealed.

In such instances, it is preferable to purchase a new device. We hope you found the information presented above to be useful.

Do you have any additional restroom concerns before you leave? Perhaps you’d want to add a bidet to your current bathroom. If that’s the case, read this post to learn how.

You might also be interested in learning more about the toilet’s lifetime. If the response wasn’t adequate, check out our page here for further information. Until next time, take care!