Replace a bathtub overflow gasket
Renew the seal behind a conventional overflow plate and check it under controlled water flow.
Home · 45–90m · Medium
Before you start
Keep the tub out of use and the floor dry. Use existing rear access to support the elbow and watch for leaks. Stop for corroded screws, a cracked fitting, movement of connected pipework or no way to inspect the repair. Never block the overflow inlet with caulk.
Tools and materials
- Exact-fit overflow gasket and compatible cover screws if needed
- Matching screwdriver, flashlight and soft cleaning cloth
- Bucket, towels, gloves and eye protection
Check the problem
Locate the leak without flooding
From rear access, dry the assembly and inspect for tracks around the overflow elbow. A leak during ordinary low-level draining may come from another joint. Do not fill the tub to reproduce a known leak.
Match the gasket design
Identify the overflow assembly and compare the replacement profile with its parts drawing. Gaskets may be tapered or shaped; do not assume every one has the same thickness or orientation.
Steps
Drain and support the fitting
Empty the tub. Cover the floor drain, protect the finish and place towels below the rear connection. Have a helper support the overflow elbow through the existing access opening.
Remove the cover carefully
Undo the cover screws while the elbow stays supported. Withdraw a trip-lever linkage gently if present and keep its adjustment unchanged. Retain small hardware away from the floor drain.
Remove the old gasket and clean
Ease out the old gasket from behind the tub wall without levering the pipe. Wipe both sealing faces. Stop for cracked, distorted or badly corroded parts rather than sealing over them.
Seat the replacement behind the tub
Fit the gasket between elbow and tub in the specified orientation. Center the passage and ensure the seal lies flat all around. Do not move the gasket to the inside beneath the cover.
Refit and secure the cover
Restore linkage if present, then start the screws by hand. Tighten evenly only as specified while the elbow is supported. The cover must be secure with its overflow entry unobstructed.
Test with a helper watching behind
With the floor drain open, direct a small controlled flow into the overflow while a helper watches the rear seal. Stop immediately if wet. Once dry and sound, check stopper operation and normal tub drainage; recheck the rear joint before closing access.
Rear overflow gasket and adjacent joints remain dry under controlled overflow flow; cover inlet, stopper and drain function normally.
Tips
Follow the gasket drawing
The thick edge is not universally placed at the bottom; it must match the tub angle and assembly.
Keep the repair local
If moisture begins below the elbow or during low-level drainage, investigate that joint instead.
Leave time for the final check
Keep the rear access open until testing is complete and every disturbed connection stays dry.