Step-by-step fix
Step 1: Make sure the overflow gasket is the likely leak point
- Look for signs that the leak happens only when water splashes high on the tub wall or enters the overflow opening.
- If you have access below or behind the tub, check whether the area around the overflow pipe gets wet during bathing but stays dry when the tub simply holds water below the overflow.
- Wipe the overflow plate area dry, then run water against the overflow opening for a minute and watch for fresh leaking behind the wall or below the tub.
If it works: The leak pattern points to water getting past the overflow plate gasket.
If it doesn’t: If the tub leaks even when the water level stays well below the overflow, check the drain shoe, waste-and-overflow connections, tub spout, or caulk instead.
Stop if:- You find active rot, mold damage, or a soft wall around the overflow opening.
- The leak appears to come from a cracked tub, broken piping, or another part of the drain assembly.
Step 2: Set up the tub and remove the overflow plate
- Put a towel in the tub so dropped screws do not chip the finish or disappear down the drain.
- Use the correct screwdriver to remove the overflow plate screws while supporting the plate with your free hand.
- Pull the plate straight out gently. If your tub has a trip lever attached, ease the plate outward carefully so you do not bend the linkage.
If it works: The overflow plate is off and you can see the old gasket or the overflow opening behind it.
If it doesn’t: If the plate is stuck from paint, soap buildup, or old seal residue, work around the edges gently with a plastic putty knife instead of prying with metal.
Stop if:- A screw will not loosen and starts stripping badly.
- The overflow elbow drops back into the wall cavity or feels completely loose behind the tub.
Step 3: Remove the old gasket and clean the opening
- Reach into the overflow opening and pull out the old gasket by hand or with needle-nose pliers.
- Note how the old gasket sat in place before removing it fully, especially if it is thicker on one side.
- Clean off soap film, old residue, and loose debris from the tub opening and the visible face of the overflow elbow.
- Wipe the area dry so the new gasket can sit flat and seal evenly.
If it works: The old gasket is out and the overflow opening is clean and dry.
If it doesn’t: If the gasket breaks apart, remove all leftover pieces before installing the new one so the new seal is not distorted.
Stop if:- The metal overflow elbow is badly rusted through, cracked, or misshapen enough that a new gasket cannot seal against it.
Step 4: Install the new bathtub overflow plate gasket
- Compare the new gasket to the old one for shape and thickness before installing it.
- Place the new gasket around the overflow opening in the same orientation as the original. On many tapered gaskets, the thicker side goes at the bottom to match the tub wall angle.
- Hold the gasket in place and make sure it sits evenly without twisting, folding, or bulging into the opening.
If it works: The new gasket is seated evenly and matches the opening without distortion.
If it doesn’t: If the gasket will not sit flat, remove it and recheck the orientation, size, and whether old debris is still trapped behind it.
Stop if:- The replacement gasket is clearly the wrong size or profile for the overflow opening.
Step 5: Reinstall the overflow plate without shifting the gasket
- Set the overflow plate back in position carefully so the gasket does not slide out of place.
- Start both screws by hand before tightening either one fully.
- Tighten the screws a little at a time, alternating sides so the plate pulls in evenly.
- Snug the screws just enough to compress the gasket and hold the plate firmly. Do not overtighten and risk cracking the plate or distorting the seal.
If it works: The plate is secure, centered, and the gasket stayed in place during tightening.
If it doesn’t: If the plate sits crooked or the gasket squeezes out, remove the plate and reset the gasket before trying again.
Stop if:- The screw holes do not line up because the overflow elbow is out of position behind the tub.
Step 6: Test the repair under real use conditions
- Dry the area below or behind the tub if you have access so new moisture is easy to spot.
- Run water into the tub and direct water at the overflow opening for several minutes, or fill the tub until water enters the overflow briefly.
- Watch the wall, ceiling below, or access opening for any sign of fresh leaking.
- After the test, check again 10 to 15 minutes later to make sure no slow seepage appears.
If it works: No water shows up behind, below, or around the tub during or after the overflow test.
If it doesn’t: If it still leaks, remove the plate and confirm the gasket orientation, fit, and seating. If those look correct, the leak may be from the overflow elbow connection or another part of the waste-and-overflow assembly.
Stop if:- Water still leaks after the gasket is correctly installed and tightened evenly.
- You see hidden water damage getting worse during the test.
Replacement Parts
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FAQ
What does a bathtub overflow plate gasket do?
It seals the gap between the tub wall and the overflow elbow behind the overflow plate. Without a good gasket, water entering the overflow opening can leak into the wall or ceiling below.
Do I need plumber's putty or caulk on the overflow gasket?
Usually no. The gasket is meant to seal by compression when the plate is tightened. Extra sealant can make the fit messy and may not solve a bad orientation or wrong-size gasket.
Which way does the overflow gasket go?
Match the original orientation if possible. Many overflow gaskets are tapered, and the thicker side often goes at the bottom because the tub wall is angled there.
Can I replace the gasket without opening the wall?
Usually yes. Most overflow plate gaskets can be replaced from inside the tub by removing the overflow plate. You only need wall access if the overflow elbow is loose, damaged, or drops out of position.
Why does the tub only leak when someone showers or takes a bath?
That pattern often points to the overflow area. Splashing or a high water level sends water into the overflow opening, and a worn gasket lets that water escape behind the tub.