Things You'll Need
Tub drains are typically two pieces: the drain and the overfill tube. Installing a tub drain requires fitting the drain and overflow tube, which piece together to form an L-shaped unit, to the tub. The overflow tub secures to the top with screws through the cover plate that grabs the overflow tube. The drain is secured to the tub by screwing the drain basket down from inside the tub but requires sealant. Sealing an existing or new drain basket is easily done with plumber's putty.
Remove the pop-up drain if installed. Most pop-up drains unscrew by firmly grasping and rotating the drain while in the up position. Some pop-up drains have a horizontal screw in the side of the drain. Lift the pop-up drain and rotate it until you see the screw. Remove the screw with a screwdriver or Allen wrench, allowing the pop-up drain to lift out. Some types require you unscrew the top cap by holding the larger base of the pop-up drain to expose a retaining screw.
Unscrew the existing drain using a basket wrench, which is a specialized tool that looks like a short-metal pipe with a rod running through it horizontally. The tool is available at any hardware store. Press the tool down into the drain to grab the edges of the drain and rotate. The drain will loosen and come free. Do not fully remove the drain. Unscrew the drain until it sits approximately 1/2 inch above the tub floor.
Dry the drain and tub with a towel to remove any residual moisture. Remove any existing or damaged gaskets or putty from around the drain basket.
Roll out a piece of plumber's putty until it is approximately 1/2 inch thick and long enough to wrap around the drain.
Wrap the roll of putty around the drain and pinch the ends together. Press the roll beneath the lip of the drain basket.
Twist the basket down using the basket wrench until the basket is flush with the surface of the tub. The putty will squeeze out the sides of the drain. Remove excess with a screwdriver or scraper. Reinstall any pop-up drains the opposite of the removal.