Toilet Leaking at the Base? Causes and Fixes

Water on the floor around the toilet is one of those problems that's easy to wipe up and forget. But if it keeps coming back, something is leaking, and toilet leaks can damage flooring, baseboards and the subfloor over time. Here's how to find the source and what to do about it.

Step 1: Find Where the Water Comes From

Dry everything completely, including the floor, the base, the tank and the pipes. Then watch over the next few hours, or put a few sheets of toilet paper around the base to see where they get wet first.

Is It Condensation?

In Florida's humidity, cold water in the tank makes the outside of the tank "sweat," especially in summer or when the AC is running hard. The drips run down and pool at the base. If the outside of the tank is beaded with water, that's likely your answer. A tank liner, better bathroom ventilation or running the bathroom fan helps. It's not a leak, but it can still damage the floor over time.

Is It the Supply Line or Shut-Off?

Check the flexible line that runs from the wall valve to the bottom of the tank, and the valve itself. A drip from either connection can run down to the floor. Tightening the connection slightly may stop it. If the line is old plastic or rubber, replace it with a braided stainless steel line. If the valve leaks or won't turn, it needs replacing.

Is It the Tank?

Check where the bolts hold the tank to the bowl, and the large seal between them. Worn bolt washers or a failed tank-to-bowl gasket can drip, especially when you flush. A hairline crack in the tank also leaks. Gaskets and bolts can be replaced. A cracked tank or bowl means a new toilet.

Is It the Wax Ring?

If water appears around the base only when you flush, and everything above is dry, the wax ring is the likely cause. The wax ring seals the toilet to the drain in the floor. Signs it's failed:

• Water at the base after flushing
• A sewer smell around the toilet
• The toilet rocks or feels loose
• Stained or discolored grout or flooring around the base

The fix: shut off the water, drain the toilet, disconnect it, lift it off, scrape off the old wax, check the flange underneath for damage, install a new wax ring, and reset and level the toilet. It's doable for a confident DIYer, but toilets are heavy and awkward. A damaged or broken flange, or a floor that's soft around the toilet, is a job for a plumber.

Don't Ignore a Wobbly Toilet

A toilet that rocks breaks the wax seal a little more every time someone sits down. Tightening the floor bolts gently can help, but don't overtighten, since that can crack the base. If it keeps rocking, the toilet needs to be reset or shimmed.

Repair or Replace?

Wax rings, supply lines, gaskets and bolts are inexpensive repairs. A cracked toilet, or an older one that also runs or clogs often, is a good candidate for replacement with a modern high-efficiency model. See when to replace your toilet and toilet keeps running.

Toilet Leak Help

Believe Plumbing repairs and replaces toilets across Tampa Bay, including Tampa, Carrollwood and Pinellas Park. See our toilet services or contact us.