Symptoms
- Puddle appears periodically, not always after flushing
- Toilet seems otherwise normal
- No obvious crack or loose bolt
- Puddle location shifts slightly
Likely causes
- CommonCondensation from the tank dripping downA cold, sweating tank in a humid bathroom can drip onto the floor and look like a base leak.
- CommonSplashing from bathing or a nearby showerWater tracked in from a shower or bath can pool near the toilet if it's close by.
- PossibleSlow wax ring leak that only shows with heavier useA partially failed seal may only leak enough to notice after multiple flushes in a row.
- PossibleSupply line or shutoff valve seeping intermittentlyA loose fitting can drip only under certain pressure conditions.
What to do
- Dry the entire area completely, including under and around the toilet, tank, and supply line.
- Flush multiple times over 15–20 minutes and watch closely for exactly where new moisture first appears.
- Feel the tank for condensation buildup, especially in warm, humid weather.
- Check the supply line and shutoff valve connections for even a slight dampness.
- If the base itself seems to be the source after several flushes, treat it as a wax ring issue (see that guide).
Tools and parts
- Towels
- Flashlight
When to call a pro
Call a plumber if you can't pinpoint the source after careful observation, since a professional can pressure-test connections and check the seal.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.