toilet leaking from bottom

Causes of Toilet Leaking from Bottom and How to Fix/Prevent It

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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You’ve started to notice water pooling at the base of your toilet. Is water leaking at the base of your toilet, or are there issues with the supply line?

A toilet leak is something you can repair yourself or get a professional plumber to do it. However, that depends on what is causing the leaking and the extent of the repair. So what are some things that can lead to your toilet leaking from bottom or side parts, and what can you do about it? Let us find out.

Why Is My Toilet Leaking?

Why is My Toilet Leaking?

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1) Damaged or Old Wax Ring

Wax rings come in handy to keep the water line closed at the base of your toilet. If there is leaking in that area, then the reason is probably a broken or old wax ring.

Since wax rings mold easily to fit into the shape of the toilet base and keep the water away, it is the most preferred material for use by plumbers. However, the substance is a delicate material that, if not fixed properly by a professional plumber, can cause toilet leaks.

2) A Loose Water Supply Line

Water gets into the toilet tank via a supply line, and leaks can occur when this line is faulty. One way to tell that the leak is coming from a water supply line is when it is constant, even when you have not flushed the toilet.

The supply line can cause a toilet leak at the tank, and you might not immediately notice where the leak is. After all, water naturally flows downwards, and the floor is where you will most likely see a leak. Therefore, if you notice a leak on the floor, try to follow it to the source, as it is not obvious that you have a leaky toilet base.

3) Loose Flange Bolts

One way to fix a leaking toilet is to ensure it is tightly held to its position. The moment the toilet bowl is rocking, breakage might be caused, or loose parts might remain exposed, causing leakage. Also, the toilet’s base might have tiny cracks that are never harmful in normal cases. However, you can have a leaky toilet base when these lines get too deep.

4) Cracked Bowl

A cracked bowl at the bottom of the toilet will lead to leaks. The bowl has a water-tight seal because it is the part that holds water most of the time. If there are any cracks, even tiny ones, you can expect to see a leaky toilet sooner or later.

One way to tell the bowl is cracked is when the leaking at the base is constant and happens even without you flashing the toilet.

5) Loose Handle/Knob

Loose Handle/Knob

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Some water tanks have a handle or a knob on the side. The component might be below the water level on such toilet tanks. If these parts are loose, water might start leaking out of the tank. You can catch such a leak more easily than other variations I have discussed above.

A wax seal never works for such leaks, and you must replace or repair the loose or damaged parts.

6) Clogged Drain Line

When there is clogging, water will find somewhere else to go, which might be the floor. Of course, clogged lines are the last thing you want, but they can be possible. For example, a clogged line prevents toilet bowls from emptying their water outside the house into a septic tank or drainage. To handle the issue here is how to unclog a toilet.

7) Condensation

The pool on your floor can be a result of condensation. There are instances when the humidity is too high, and since the toilet bowl is made of porcelain, it tends to be very cold, leading to condensation. However, this is not something to worry about.

8) Loose Shut Off Valve

The shut-off valve is the part of the toilet tank that stops more water from flowing into the tank after it gets full from replacing the flushed water. After all, water will flow endlessly into the tank when this valve fails, causing a leakage.

Moreover, water may start seeping out of the toilet tank lid and go unnoticed for a while. If the shut-off valve is problematic, it may be because of a smaller problem, like the floater getting stuck on something. Alternatively, the fill valve arm may have a rusty or stuck bolt that can lead to malfunctioning, and this is something you can watch out for.

How to Fix a Leaking Toilet

How to Fix a Leaking Toilet

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While you may need a plumber to fix a leaking toilet, the common causes may be things you can sort out on your own. Here are some tips to help you out.

a) Get a New Wax Ring

If you have established that the wax ring you are using might be the problem, it is time to get a new one. However, the one thing that most people need to remember is that even a new ring can still cause leakage if not installed properly. But, if you have installed a new wax ring, it is only a matter of a few hours till you notice the difference.

Never install the new seal over leftovers from the old wax. Thus, ensure the old wax ring is scrapped off, and there is none left behind. A putty knife can do a great job of scrapping off the wax.

b) Tighten Tee Bolts

Since loose bolts can lead to leakage and even more damage to the toilet, it is time to tighten any loose bolts. The bolts are normally located under the plastic caps at the bottom of the toilet.

Once you remove the caps, you will find bolts that you can remove, replace, or tighten. Importantly, when the toilet is leaking, turning off the water supply line is best to give you an easy time when doing the toilet repair work.

Moreover, loose bolts may cause toilet wobbles, leading to a failing wax ring. Still, installing a new wax ring might be pointless if the toilet is moving.

c) Check for Signs of Condensation

Before getting your tools, the water leaking at the base could result from condensation. Check for condensation, and the solution might be far from doing any repairs.

Condensation can lead to mold growing in your toilet tank. While there are ways to clean mold from surfaces, you want to avoid getting to that point.

You can use a bathroom exhaust fan whenever the humidity levels are high. Shorter and cooler showers have proven useful, too, in keeping condensation levels low. Furthermore, you can leave the windows open.

d) Connect the Water Supply Line

 Connect the Water Supply Line

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The water supply line is the main culprit for a leaky toilet most of the time. Once you have established that the problem is a loose or broken supply line, then you can get to work. Using a crescent wrench is all you need to know to solve the problem.

You may need a plumber to replace a supply line because they can do it better most of the time. Additionally, since the component is typically hidden, a plumber can tell, especially if all you can see is water pooling every time you flush the toilet.

e) Reinstall the Toilet

While I am not advocating throwing the child away with the birth water, sometimes all you need is a change. When reinstalling the toilet, ensure no loose parts, from each compression nut to the bolts on the floor.

While reinstalling the toilet will involve removing the whole toilet, you may need a plumber to help.

How to Prevent Toilet Leaks

How to Prevent Toilet Leaks

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1) Only Flush Flushable Items

Refrain from flushing everything down the toilet drain. While it may seem convenient to flush harmful objects or things you want to hide down the toilet, it might damage or block the drainage, leading to a leaky toilet.

2) Fix a Leaking Toilet Straight Away

While remodeling your bathroom is the best time to make repairs, you do not have to wait until that time. Once you have established a leaky toilet base, there is no need to wait and see if it goes away. After all, fixing the issue is better than replacing the whole toilet.

So get new t-bolts if you have to, and avoid reusing old parts. Luckily, plumbing materials are never too costly, and you can take advantage of this.

3) Avoid Chemical Drain Cleaners

Some cleaners have harsh chemicals that can lead to a lot of damage to the toilet. Avoid such cleaners at all costs, as they may lead to you replacing the entire toilet.

4) Avoid Using a Wobbly Toilet

If a toilet is not tied down properly, it is only a matter of time before something else happens that will lead to a leak. A loose toilet seat is the surest way of getting numerous types of leaks and is the worst thing that can happen to the toilet.

Final Thoughts

Final Thoughts

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There are a few reasons that may lead to a leaky toilet. The problem will cause maximum stress if you do not fix it once you find a leak somewhere. Inspecting the toilet is one sure way to avoid future water pooling at the base. Luckily, most leaks are always something you can handle.

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Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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