A bathtub with a leaky drain can cause damage to a bathroom floor -- and a ceiling below if the tub is located on a second level. It's important to treat a leaky bathtub promptly to prevent water damage. The most common cause of a bathtub leak is an old and cracked seal around the drain. The seal works to keep the water inside the drain. When the seal fails, the bathtub will begin to leak. Use plumber's putty, which can be found at most hardware stores and home improvement stores, to fix a leaky bathtub drain.
Unscrew the bathtub drain by rotating it with your fingertips using a counterclockwise motion. You should find a seal of putty underneath the drain.
Heat the old seal using a hair dryer. The heat will soften the putty, making it much easier to remove.
Remove the putty using a screwdriver to scrape and lift it from the tub.
Apply plumber's putty around the drain hole.
Place the drain over the putty and tighten it into place with the screws.
Wipe away any excess putty using a cloth.