How to Fix a Leaking Tub

A tub leak has fewer suspects than a shower — but the fix depends entirely on which one it is.

Common causes

• Overflow gasket cracked or missing
• Drain shoe seal failed under the tub
• Spout cracked or diverter stuck
• Valve behind the wall leaking

Step-by-step

1. 01Fill the tub above the overflow — leak below suggests overflow gasket
2. 02Fill the tub to the drain only — leak below suggests drain shoe
3. 03Run the tub spout — leak on the wall side = valve or spout
4. 04Check under the tub if there's access below (basement ceiling)

When to call Northbridge

• Access is closed and drywall needs to come down
• Drain shoe is under a cast-iron tub
• Valve behind the wall is leaking
• Ceiling below is soft or stained