If water shows up under the tub only after a deep bath, the sponge gasket behind the overflow plate has likely failed. Replace it with one that matches the old size, such as the Danco 88932 (2-15/16 × 1-7/8 inches) or Danco 36548B (3-3/16 × 2-1/8 inches). You need access behind the tub to do it right.
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This guide covers the overflow gasket on a standard alcove tub and the exposed drain on clawfoot tubs.
Where the overflow gasket sits, and why it leaks
A tub’s overflow is the round opening under the faucet. Behind the tub wall, the overflow elbow of the waste-and-overflow pipe presses against the back of the tub. A sponge-rubber gasket fills that joint. Danco describes its waste-and-overflow gasket (danco.com) as fitting between the tub and the overflow drain to give a positive seal.
When that gasket hardens, shrinks or slips, water that rises to the overflow runs down the outside of the tub instead of into the pipe. The usual sign is a ceiling stain or drip below the tub that shows up only after deep baths, not after showers.
A second, thinner gasket sometimes sits under the overflow plate on the inside of the tub. Danco sells a separate one for standard round overflow plates (danco.com). Replace both while the plate is off.
Confirm the source before you buy parts. Run a shower for a few minutes with the drain open: if nothing leaks, the drain shoe and trap are probably fine. Then fill the tub to just below the overflow and wait: a leak now points to the drain shoe gasket at the bottom of the tub. Finally fill it until water flows into the overflow: a leak that appears only then is the overflow gasket.
Check the faucet and spout too. A leaking spout connection or valve behind the wall can drip into the same ceiling, and it will leak whether the tub is full or not.
Danco 88932: adjustable sponge gasket, 2-15/16 × 1-7/8 inches
Choose the Danco 88932 when your overflow elbow uses the smaller size. Danco’s product page (danco.com) lists sponge-rubber construction, 2-15/16 inches outside diameter by 1-7/8 inches inside, and calls the gasket entirely adjustable.
On October 15, 2026, the standard new offer from a third-party seller showed stock with model and part 88932.
Check Danco 88932 overflow gasket on Amazon →
Danco 36548B: the larger 3-3/16 × 2-1/8-inch size
Choose the Danco 36548B when the old gasket measures about 3-3/16 inches across. The listing gives 3-3/16 inches outside by 2-1/8 inches inside; Danco lists the same dimensions and sponge-rubber build for its 88350 waste-and-overflow gasket (danco.com).
On October 15, 2026, the standard new offer from a third-party seller showed stock with model and part 36548B.
Check Danco 36548B overflow gasket on Amazon →
LASCO 02-3027: a sponge gasket alternative
Choose the LASCO 02-3027 if the Danco sizes are out of stock. The listing describes a bathtub sponge gasket for the waste-and-overflow plate, model and part 02-3027.
The listing does not give dimensions, so compare it with your old gasket before installing. On October 15, 2026, the standard new offer from a third-party seller showed limited stock.
Check LASCO 02-3027 sponge overflow gasket on Amazon →
Replacing the gasket from the access panel
Most tubs have an access panel behind the drain end, in a closet or the next room. If there is none, you may need to open the wall or ceiling below; a drywall patch is often easier than working blind.
Remove the two screws on the overflow plate, pull the plate and any trip-lever linkage, and loosen the overflow elbow from behind. Peel off the old gasket and clean the tub surface around the opening.
Slip the new gasket onto the elbow, matching the old gasket’s orientation; note which way it faced before you discard it. Pull the elbow back against the tub and refit the plate. If you had to open drywall, our drywall patch kit guide covers the repair.
Test by filling the tub above the overflow and watching the joint from behind before closing the panel.
When to replace the whole waste and overflow
If the overflow elbow is cracked, the slip nuts are corroded, or the shoe at the drain also leaks, replace the full waste-and-overflow assembly instead of chasing one gasket. Measure the tub drain thread first.
Our bathtub drain types guide covers drain kits by type, coarse versus fine threads, and complete trim kits, and our tub stopper guide covers the stopper alone.
Clawfoot tubs use an exposed drain
A clawfoot or other freestanding tub with feet has its drain and overflow out in the open. The waste-and-overflow is a finished, exposed assembly that runs from the overflow hole down to the drain and then into the floor.
The Kingston Brass CC2080 is one example: the listing describes a clawfoot tub waste-and-overflow drain in matte black, model CC2080. On October 15, 2026, the standard new offer sold by Amazon.com showed limited stock.
Measure the distance from the overflow hole to the drain hole, and check the tub wall thickness and the drain thread before ordering. Our freestanding tub guide covers drain location and floor rough-in.
Check Kingston Brass CC2080 clawfoot waste and overflow on Amazon →
Frequently asked questions
Why does water leak under my tub only after a bath?
Water reaching the overflow can leak past a hard or shifted overflow gasket behind the tub wall. Showers do not raise the water that high.
What size tub overflow gasket do I need?
Measure the old one. Danco lists common sizes of 2-15/16 × 1-7/8 inches and 3-3/16 × 2-1/8 inches.
Can I replace the overflow gasket without an access panel?
Often only by opening the wall or ceiling behind or below the tub. Check for a panel in a closet or the next room first.
Do clawfoot tubs use the same overflow gasket?
Clawfoot tubs use an exposed waste-and-overflow assembly, usually with its own gaskets. Replace the assembly or use the gaskets it was sold with.
How do I know the leak is the overflow and not the drain?
Fill the tub in stages. A leak with the tub just below the overflow points to the drain shoe; a leak only when water runs into the overflow points to the overflow gasket.
How we chose
This document-based guide makes no hands-on testing claim. We read Danco’s current overflow gasket pages and matched each Amazon listing to its model number. On October 15, 2026, all five linked standard new offers showed stock. Read our selection method and about Plumbing Picks.
Primary sources
- Danco 88932 overflow plate gasket (danco.com): sponge rubber, 2-15/16 × 1-7/8 in., adjustable.
- Danco 88350 waste and overflow gasket (danco.com): fits between tub and overflow drain; 3-3/16 × 2-1/8 in.
- Danco 89053 overflow plate gasket (danco.com): fits standard round overflow plates.