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5 Common Causes That Can Lead to Toilet Leaking from the Base

You aren’t alone if you’re wondering why your toilet is leaking at the base. A toilet leaking from the base is a common problem that a professional can often fix quickly and efficiently.
Leaky toilets are more than just an annoyance—they can cause water damage, as well as a musty smell that permeates the whole bathroom. If you have children or pets who spend time in the bathroom, this can be especially dangerous: the contaminated water from a leaky toilet contains all sorts of bacteria and germs that can make you sick.
This article will discuss the most common causes of a toilet leaking from the base.

5 Common Causes of Your Toilet Leaking at the Base

Water Shutoff Valve Is Leaking

The toilet water shutoff valve is like any other valve or tap. It’s prone to leaking with wear and tear. To test whether it is leaking, place a small cup or bowl under the shut-off valve, then flush the toilet and turn off the water supply.

If the tap is working, you’ll hear the water supply cutting off, and the toilet won’t refill. If not, get a plumber to tighten or replace the valve’s seal.


As cold water enters your toilet’s tank, it changes the outside temperature of the tank. In warmer spring or summer weather, water can condense on the outer surface of the toilet tank. This collection of water then runs down your toilet onto lower surfaces. If this is happening, then it is not a toilet leak.
If you have a proper seal between your tank and bowl, condensation should not be an issue. If you are unsure how to check this, ask an expert plumber to come out and inspect your toilet for any leaks or cracks that could be letting water escape from your tank into places it should not be.

Worn-Out Wax Ring

A toilet leaking from the base can happen for various reasons, but most commonly, it is because of the wax ring beneath the toilet. The wax ring creates a watertight seal between the drainpipe going to your septic tank or sewage system and the toilet itself. To maintain its integrity, it must be in position and properly compressed.

If the toilet shifts out of place, then this seal will likely break. In some cases, the wax can also dry out and crack. You will need your local plumber to replace them as soon as possible to maintain sanitary conditions in your home.

Loose Toilet Bolts

Toilet bolts are a surprisingly complicated part of a toilet. They hold the toilet to the floor, and when damaged, it can lead to water all over your bathroom floor and eventually cause significant water damage!
Your local plumber can help with this problem. If your toilet bolts are loose, water can seep out onto the floor, especially after flushing. There’s no easy way to fix this problem at home—you’re going to need a professional to do the job.
Your plumber will first dry the area with a towel. Then after tightening the bolts, apply Permatex (or another sealant) to each bolt, spreading it evenly and covering the entire area. After drying, any area from which the water might escape should be firmly fixed, resolving the problem.

Porcelain Cracks

Another common cause of a toilet leaking from the base is if there is a crack in the porcelain.
Has your toilet ever been the victim of a dropped item? If an item heavy enough falls into your toilet, you could be looking at a cracked porcelain bowl! That’s not all. IF weight is unevenly applied to the toilet, that can also cause cracks.
The good news is that porcelain is pretty resilient. Consequently, toilets last for decades with regular use. So, it doesn’t take much to make sure your toilet lasts a good long while! Routine cleaning and maintenance are key to keeping your toilet from developing unsightly stains and cracks.

A good rule of thumb is to clean your entire toilet—not just the bowl—and inspect it for any hidden damage each week. This damage includes crevices like the back of the tank and under bowl’s rim, which often go unnoticed.

If you find a crack in your porcelain, you may be able to temporarily fill it with a plumber’s putty or caulk until you’re able to replace the toilet completely. However, this is just a temporary measure to prevent further leaking, and you should contact your professional plumbing service for further advice.

Get Help with Professional Toilet Repair and General Residential Plumbing in Vaughan, ON, Today!

All homeowners dread dealing with a toilet leaking from the base. It’s not something to be taken lightly, either. Just one leak can do massive damage to your home and property.
Even though your first instinct might be to take matters into your own hands and try to fix it yourself, you must be careful. If you don’t know what you’re doing when it comes to leak repair, you could end up making the problem even worse.
Plus, even if you do know what you’re doing and manage to fix the leak yourself, there’s still a chance that the problem will return to cause yet another emergency disruption in your day.
Instead of trying to be a hero, attempting to fix a toilet leaking at the base (which can end up being a herculean task), why not just call a plumber? A professional plumber will have the right tools and know-how to get the job done right the first time.

Get a toilet leak taken care of correctly by calling MT Drain and Plumbing. We are here for all your household plumbing needs and proudly serve Vaughan, Markham, Richmond Hill, Toronto, Barrie, Newmarket, Etobicoke, and all surrounding areas. Give us a call today at (905) 761-5551 for service.


Paul S

Paul has more then 20 years in basement waterproofing and plumbing projects experience. Looking for an advice from an expert plumber? Make sure to read Paul's articles about residential waterproofing and plumbing projects in Toronto.

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