A leaking or corroded tub drain doesn't always require a costly call to a plumber. Replacing it yourself takes about an hour, requires only a few basic tools, and saves you hundreds of dollars in service fees.
Tub drains typically fail because the rubber gasket underneath degrades, threads strip, or the metal corrodes from decades of exposure to standing water and harsh cleaners. Tackling this project means dealing with two main styles: standard lift-and-turn stoppers and older trip-lever mechanisms. Once you figure out which style you have, the replacement process comes down to removing the old hardware, cleaning the seating surface, and sealing the new drain with fresh plumber's putty or silicone.
Identifying Your Tub Drain Type and Tools Needed
Before you grab a wrench, look closely at your current drain assembly. Most modern bathtubs use either a lift-and-turn drain, a push-pull stopper, or a toe-touch stopper. Older homes might feature a trip-lever overflow plate that connects to a mechanical linkage inside the drain pipe.
To remove and replace most standard tub drains, you need a specialized tool called a tub drain wrench (or drain removal wrench). Standard pliers won't grip the crossbars inside the drain basket properly, especially if they are corroded.
Gather these materials before you begin:
- Tub drain wrench or heavy-duty adjustable pliers
- Needle-nose pliers or a flathead screwdriver
- Plumber's putty or 100% silicone caulk
- Rags and a wire brush or coarse scrubbing pad
- Penetrating oil (such as WD-40) for stubborn, rusted threads
- New tub drain assembly matching your tub's finish
Step 1: Removing the Old Drain Stopper
Your first task is getting the stopper and basket out of the way. The removal method depends entirely on the stopper mechanism installed in your tub.
For a lift-and-turn stopper, open the drain, look for a small set screw on the side of the stopper cylinder, and loosen it with an Allen wrench. If it's a push-pull or toe-touch stopper, unscrew the entire stopper counterclockwise while holding the body steady.
Once the stopper is out, you'll see the crossbars inside the drain basket. Insert the arms of your tub drain wrench into the drain opening so they catch securely against these crossbars. Slide the handle of a screwdriver through the hole in the top of the wrench to gain leverage, then turn counterclockwise to unscrew the drain basket.
If the drain basket is stubborn or rusted in place, spray penetrating oil around the threads and let it sit for 15 minutes. If the crossbars snap off due to heavy corrosion, don't panic. You can use an internal tub drain extractor tool, which wedges inside the drain pipe and grips the walls so you can turn it out.
Step 2: Cleaning and Preparing the Tub Surface
With the old drain basket removed, look at the metal flange around the drain hole on the inside of the tub. Over the years, old plumber's putty, mineral deposits, and soap scum build up here.
Use a putty knife or a flathead screwdriver to scrape away the crusty remnants of the old seal. Follow up with a wire brush or abrasive scrubbing pad to clean the metal until it's completely smooth and bare. Any leftover residue prevents the new seal from bonding properly, which leads to leaks beneath the tub.
Take a clean rag and wipe out the opening. If you have an open access panel behind the tub—common in many homes—take a flashlight and check the PVC or brass shoe and gasket underneath to ensure everything looks dry and intact.
Step 3: Applying Sealant and Positioning the New Drain
Most manufacturers recommend using plumber's putty to seal a standard brass or metal tub drain. If your tub is made of acrylic or fiberglass, check the packaging; some manufacturers specify using silicone caulk instead because oil in standard putty can occasionally stain certain plastics.
Roll a lump of plumber's putty between your palms until it forms a uniform, pencil-thick snake. Wrap this rope of putty evenly around the underside of the new drain basket flange, pressing it gently so it forms a continuous ring.
Thread the new drain basket into the drain shoe beneath the tub by hand, turning clockwise. Hand-tightening ensures you don't cross-thread the delicate metal threads. Make sure you turn it slowly and carefully.
Step 4: Tightening and Testing the Assembly
Insert your tub drain wrench back into the crossbars and tighten the basket another quarter to half turn. You want it snug, but don't over-tighten it, or you risk cracking the porcelain or warping the metal flange.
As you tighten the drain, excess plumber's putty will squeeze out from beneath the rim. Wipe away this excess putty with a clean rag.
To test your work, fill the bathtub with a few inches of water and check underneath the tub (if you have access) or simply let the water drain while watching the seal. If you don't see any drips and the water drains quickly, you're ready to reinstall your stopper.
Common Mistakes to Avoid
DIY plumbing projects often go sideways due to a few avoidable errors. Keep these pitfalls in mind while you work:
- Cross-threading the drain: If the drain basket offers heavy resistance immediately when you try to screw it in, back it out completely. Forcing it ruins the threads on the tub shoe, turning a simple thirty-minute swap into a major plumbing repair.
- Skipping the cleanup phase: Leaving old, crusty putty on the tub surface creates gaps in the new seal. Take the extra five minutes to scrub the surface down to bare metal.
- Using the wrong sealant: Always verify whether your tub material requires silicone instead of traditional plumber's putty to protect the finish.
Frequently Asked Questions
What should I do if the crossbars break off inside the old drain?
Crossbars often snap on older drains due to rust. When this happens, use an internal pipe wrench or an internal tub drain extraction tool designed to grip the inside of the drain cylinder without needing the crossbars.
Can I replace a tub drain without accessing the underside of the tub?
Yes. Standard tub drain replacements happen entirely from inside the bathtub. You don't need access to the plumbing beneath or behind the tub unless you are also replacing the PVC pipes or the rubber waste-and-overflow gasket.
How long should plumber's putty cure before I use the tub?
Plumber's putty doesn't actually need a curing time like silicone caulk does. Once you wipe away the excess putty and tighten the drain, you can fill and use the bathtub immediately.
Why is my new tub drain leaking after installation?
Leaks usually happen because not enough putty was used to form a complete seal, or the drain basket wasn't tightened down enough to compress the putty against the tub floor. Unscrew the drain, clean off the old material, apply a thicker rope of putty, and tighten it down firmly.
