Installing a Bathtub Overflow Seal

Updated April 17, 2017

While bathtubs may not be as popular as showers, many people enjoy the option of a warm, relaxing bath. To make sure excess water doesn't create a mess, bathtubs have a mechanism called an overflow–and these include a seal. This mechanism ensures water doesn’t spill over the edges of the tub by doubling as an alternative drain. To keep the overflow in good working order, replace the seal when leakage occurs.

Remove the old overflow seal if necessary. Remove the cover with a screwdriver then remove the seal gasket from the inside by using pliers. Be careful not to scratch the surface of your bathtub. Buy the same overflow seal or a compatible one. If you are installing a new bathtub, skip this step. Every bathtub has a predrilled hole on the shorter side, beneath the edge, which is the standard location for the overflow seal.

Dampened a cloth with rubbing and clean the surface around the hole for the overflow seal. The area needs to be absolutely clean and dry prior to the installation. If there is any caulk left around the hole or on the bathtub surface, carefully remove it with a razor blade. If you are installing a new bathtub, clean around the predrilled hole. Dirt and dust can keep the caulk from adhering properly, resulting in a leakage.

Wipe around the hole with a dry cloth or wait until the area is completely dry.

Place the overflow seal inside the hole in your bathtub. Position the thinner part of the overflow seal on the top, on the surface of the bathtub.

Arrange the overflow seal so that it is in line with the drainage pipe screws.

Screw the bathtub overflow valve to the drainage pipes behind it with a flathead screwdriver. Use the screws from the overflow seal installation kit. Make sure to tighten the screws firmly. Make sure the overflow seal cover is even with the surface of the bathtub.

Apply silicone caulk around the edges of the overflow seal. Use a caulking gun and be precise, forming a thin line and a watertight seal all around the edges. Allow caulk to dry and settle for 24 hours before using your bathtub.


Seal gaskets need to be replaced at least every 10 years in order to be fully functional. Check your bathtub overflow seal every year for signs of tearing and damage.


Use a screwdriver with great caution while removing the old bathtub overflow seal and protect your hands with work gloves.

Things You'll Need

  • Screwdriver
  • Pliers
  • Cloth
  • Rubbing alcohol
  • Razor blade
  • Flathead screwdriver
  • Caulking gun and silicone caulk
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About the Author

Based in New Jersey, Susan Raphael has been writing technology-related articles since 1991. Her work has appeared in “Wired” magazine, and “Mac Addict” magazine. Raphael received the Janet B. Smith Literary Award in 2002. She holds a Bachelor of Science in journalism from New York University.