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What Causes a Leaking Toilet to Leak at the Base?

Have you noticed a pool of water around the base of the toilet? There could be several causes for the leaking toilet. The first thing to do is to stop using the toilet until you can locate the source of the leak. The second most important thing is to not ignore the toilet leaking at the base.

If you continue to use the toilet, more and more can get under the toilet. If the water is leaking from the toilet bowl, it can contain bacteria, smell bad, and create a sanitation issue. Plus, all that water must go somewhere.

If it isn’t going down the sewer drain, then it will seep in between the flooring and subflooring. To further complicate matters, not only will you have to deal with potential water damages, but you will also have to address issues with mold and mildew.

Finding the Source of a Leaking Toilet


A toilet leaking around the base does not always mean the leak is at the base. To find the source of the leak, you will need to do a little investigative work.

Step 1:

Start by shutting off the water to the toilet. The water shutoff should be under the toilet tank. Turn it until it is closed.

Step 2:

Clean up the water from around the base of the toilet. Remember, this water could have come from inside the bowl, so make sure to wear protective gloves. If you mop the water up, wash your mop head in hot water and bleach to kill germs and bacteria.

Step 3

Once the water is cleaned up, check for leaks coming from underneath the toilet tank. Water leaks from the tank can run down the back of the toilet and make it appear like there is a leak around the base.

Slow leaks can be harder to detect. Open the lid on the tank and verify there is water inside. If the water level is low, then the leak is probably coming from the tank, not the base.

Step 4:

If the tank is not leaking, the next step is to see if the toilet bolts are loose. The toilet bolts are normally at the back of the base and have a plastic cover over them. Remove the plastic cover and use a wrench to see if the bolts are tight. Do not overtighten the bolts, as this could crack the base.

Step 5:

If the bolts are tight, and the tank is not leaking, then it might mean the wax ring that connects the toilet to the sewer line needs replacing. Replacing the wax ring can be a messy job and does require having a general knowledge of bathroom plumbing, as well as the right tools and parts.

You will need to drain the toilet tank and remove the toilet from the floor. If you do not feel up to this task or are worried you will create more leaks or damage the toilet, then it is better to call a professional bathroom plumber for help.

While the toilet is removed, this is a good time to clean under the toilet and check the flooring and subflooring for water damage, mold, and mildew. If you discover water damage, you need to allow the affected area to fully dry out and then make any necessary repairs before reinstalling the toilet.

For help replacing the wax ring and finding the source of toilet leaks, shower leaks, tub leaks, toilet repair, toilet replacement, or other plumbing repair and replacement services, please feel free to contact MET Plumbing & Air Conditioning at 281-599-3336. We service the greater Houston, Katy, Cypress, Sugar Land, Spring, and The Woodlands areas.

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