If you notice water pooling around the base of your toilet, it’s a problem that needs attention right away. A toilet leaking at the base can damage flooring, cause odors, and indicate a failing seal — even if the toilet still flushes normally.
This issue is common and usually fixable, but it should never be ignored.
Quick Answer:
A toilet leaks at the base because the seal between the toilet and the drain has failed or the toilet is not seated securely. This is most often caused by a worn wax ring, loose mounting bolts, or movement of the toilet over time.
Why This Happens
Toilets are sealed to the drain using a wax ring or similar gasket. That seal prevents water and sewer gases from escaping during flushing.
Common causes of base leaks include:
- A deteriorated or damaged wax ring
- Loose toilet mounting bolts
- A toilet that rocks or shifts slightly
- Improper installation
- Cracks in the toilet base or flange
Leaks at the base often appear alongside sewer gas smells near the toilet or intermittent moisture after flushing.
Step-by-Step: What to Do If Your Toilet Is Leaking at the Base
Step 1: Identify When the Leak Occurs
Dry the floor around the toilet and observe.
Leaks may appear:
- Right after flushing
- Slowly over time
- Only when the toilet is used
Water appearing after flushing strongly suggests a seal problem.
Step 2: Check for Toilet Movement
Gently rock the toilet side to side.
If the toilet moves:
- The wax ring may be compromised
- The mounting bolts may be loose
A toilet should feel solid and stable.
Step 3: Inspect the Mounting Bolts
Look at the bolt caps at the base of the toilet.
- Ensure bolts are present
- Check for corrosion or looseness
Lightly tightening loose bolts may reduce movement, but it will not fix a damaged seal.
Step 4: Rule Out Condensation
Sometimes water near the base is caused by condensation, not a leak.
Condensation is more likely if:
- The tank feels cold
- The floor is wet during humid conditions
- No water appears after flushing
If moisture appears only after flushing, it’s likely a leak.
Step 5: Stop Using the Toilet if Leaking Persists
If water continues to appear at the base:
- Shut off the toilet supply valve
- Avoid flushing
- Plan for repair
Continued use can damage subflooring and lead to costly repairs.
What Not to Do
- Don’t ignore water around the toilet base
- Don’t repeatedly tighten bolts hoping it stops
- Don’t caulk around the base to hide the leak
- Don’t assume the leak will stop on its own
Caulking can trap water and hide ongoing damage.
When to Call a Professional
Call a plumber if:
- Water appears after every flush
- The toilet rocks or won’t sit firmly
- Sewer odors are present
- You’re unsure how to reseat the toilet
Replacing a wax ring is common but requires removing the toilet correctly.
Safety Notes
- Shut off the toilet supply if leaks continue
- Clean water promptly to prevent floor damage
- Avoid using the toilet if the seal is compromised
- Wear gloves when handling plumbing components
Common Homeowner Questions
Is a leaking toilet base an emergency?
It’s not always an immediate emergency, but it should be addressed quickly to prevent damage.
Can tightening the bolts fix the leak?
Only if the seal is intact. A damaged wax ring must be replaced.
Will caulking around the base stop the leak?
No. Caulk can hide leaks and worsen floor damage over time.