Introduction
Removing and replacing a tub drain is a common plumbing task that most homeowners will have to tackle at some point. Over time, tub drains can become clogged with hair and soap residue, start to leak, or the finish may become worn or damaged. Replacing a tub drain is usually a straightforward project that can be completed in an hour or two with some basic tools and plumbing skills.
In this comprehensive guide, we’ll walk through everything you need to know to successfully remove and replace a bathtub drain. We’ll cover how to prepare for the project, remove the old drain, clean the drain hole, install a new drain assembly and make the final plumbing connections. With the right information and preparation, you can avoid costly callbacks from plumbing professionals and take care of this common DIY bathroom repair on your own.
Steps to Remove a Tub Drain
Removing a tub drain involves disconnecting it from the drain pipe below, unscrewing it and pulling it up through the drain hole. Here are the key steps involved:
Step 1: Turn Off Water Supply and Drain the Tub
Before starting, locate the shutoff valves for the hot and cold water lines feeding the tub and turn them off. This prevents water from spurting out when you remove the drain. Also open the drain and allow any standing water in the tub to fully drain out.
Step 2: Disconnect and Remove Overflow Plate
Most bathtub drains have an overflow plate where the overflow drain and trip lever attaches. Remove the cover plate screws and pry the plate off with a screwdriver to access the overflow pipe. Disconnect the overflow pipe from the tub drain body and set it aside.
Step 3: Loosen Drain Body
The drain is held in place by a large nut called the shoe that sits inside the drain hole under the tub. Use tongue-and-groove pliers or a special tub drain wrench to loosen the shoe by turning it counter-clockwise. Unscrew the shoe completely to detach the drain from the drain pipe.
Step 4: Remove Old Drain
With the shoe removed, the drain body should lift out easily from the drain hole. If it sticks, rock it back and forth to break the tub drain seal while pulling up. Remove any remaining putty or debris around the drain hole with a utility knife. Discard the old drain.
Step 5: Clean and Prepare Drain Hole
Use a wire brush or abrasive pad to thoroughly scrub around the drain hole. This helps the new sealant and drain sit properly. Vacuum any loose material or standing water remaining in the drain hole. The area should be completely clean and dry for the new drain installation.
How to Install a New Tub Drain
Once the old drain is removed, installing a new one takes a few simple steps. Follow these instructions for properly installing a bathtub drain:
Step 1: Apply Plumber’s Putty
Roll out a rope of plumber’s putty around the flange of the new drain. Form it into a ring around the underside of the tub drain flange. This seals the drain to prevent leaks. Press firmly to flatten and smooth out the putty.
Step 2: Insert and Tighten New Drain
Lower the new drain into the hole from above the tub. The putty should form a seal between the flange and tub surface. Have someone hold the drain in place from below the tub if needed. Reinstall the shoe piece and tighten clockwise by hand until snug.
Step 3: Reinstall Overflow
Attach the overflow plate and plate cover with the original screws. Reconnect the overflow pipe to the new drain. Use plumber’s tape on the threads to prevent leaks.
Step 4: Tighten the Shoe
Use your tub drain wrench, pliers or a pipe wrench to tighten the shoe another quarter to half turn past hand tight. Don’t overtighen or you can crack the tub. The drain should be firmly seated.
Step 5: Reconnect P-Trap
Under the tub, realign the slip nut connections on the P-Trap with the drain pipe. Hand tighten the slip nuts. Finish by turning the faucet valves back on and testing for leaks.
Once those steps are complete, the new tub drain should be professionally installed and fully functional. The key is taking time to clean the drain hole and properly seal the new drain flange with plumber’s putty to prevent leakage.
Choosing the Right Tub Drain
There are a few variations of tub drains and finishes to consider when selecting a replacement:
- Standard or Vandal-Proof? Vandal-proof drains have a threaded stud that allows the overflow plate to screw on more securely, preventing tampering or removal. This is recommended for rental units.
- Finish – Polished chrome, brushed nickel, oil-rubbed bronze and white drain finishes are available to match most tub faucets and hardware.
- Enameled – For antique clawfoot or freestanding tubs, look for an enameled cast iron drain in matching tub color.
- Drain Style – Some drains may have a flip-open stopper mechanism or decorative cover plate for various tub designs.
Choose a finish and style to coordinate with your existing bathroom fixtures for a seamless upgraded look. Check the drain hole size when shopping for a replacement to ensure proper fit.
Removing a Stubborn, Stuck Tub Drain
Old cast iron or metal drains can sometimes prove difficult to unscrew and remove, especially in rusty or corroded drain pipes. Here are some tips for removing a stubborn tub drain:
- Spray penetrating oil around the drain body and let it sit for 15-30 minutes before trying to unscrew it.
- Use a propane torch to heat the exterior base of the drain for 1-2 minutes max. This can help break up rust and mineral deposits.
- For drains that spin in place and won’t loosen, use a hammer and screwdriver to carefully tap the drain body counter-clockwise.
- As a last resort with metal drains, you can saw into the metal shoe with a reciprocating saw and pry it apart to destroy the shoe. Replace with a new PVC tub drain.
Avoid putting excessive torque on the shoe with your wrench or pliers, as you can potentially crack the porcelain tub base. If the drain absolutely will not budge, consider cutting the drain pipe below and replacing the entire assembly.
Installing a Tub Drain in New Construction
When a tub is installed in a new bathroom or remodel project, the drain must be positioned and roughed-in prior to setting the tub. Here are the key steps involved:
Step 1: Set Drain Height and Position
Mark the desired height and position for the tub drain on the subfloor, accounting for tub model dimensions. The drain center should align 12” from the wall studs to allow space for the P-trap.
Step 2: Cut Drain Hole in Subfloor
Use a hole saw to cut a 2-1/2” to 3” diameter hole through the subfloor for the drain. Confirm the hole aligns with your drain mark before proceeding.
Step 3: Install Drain in Subfloor
Place the tub drain assembly through the subfloor with the shoe piece facing down. Secure the drain flange to the subfloor with screws.
Step 4: Run Drain Pipe to Plumbing
Attach a short section of 1-1/2” drain pipe to the drain shoe and route it to the main drain line. Leave room for the P-trap bend when connecting.
Step 5: Set and Seal Tub
With the drain positioned properly, set the tub in place over the flange. Seal the tub to the floor with 100% silicone caulk before finishing the enclosure.
Step 6: Connect Overflow and Finish
Once the tub deck is constructed, cut a hole for the overflow plate. Attach the overflow pipe to the drain, install the plate and test for leaks before finishing the walls.
The key is accurately measuring and cutting the subfloor to allow proper alignment with the tub drain hole. Taking time to correctly position the drain assembly makes installing the tub much easier.
How Can I Prevent Clogs in My Tub Drain?
Clogged drains are a nuisance that can be minimized with some simple preventive steps:
- Install a drain screen – Use a fine mesh drain screen to catch hair and debris before it goes down the pipe. Clean the screen periodically.
- Avoid grease and oil – Cooking grease or bath oils will stick to pipes and accumulate over time. Wipe any spills or residues thoroughly after bathing.
- Limit hair down drains – Hair and shampoo residue are some of the most common culprits of clogs. Use a drain catch and clean frequently to limit buildup.
- Watch what goes down drains – Avoid pouring coffee grounds, paint, chemicals or other debris that can cling to pipes and form blockages.
- Clean with baking soda – Pour 1⁄2 cup baking soda down the drain followed by 1 cup vinegar once a month to break up gunk and keep pipes clear.
- Use enzyme drain cleaner – Enzyme-based drain cleaners actively break down organic material without harsh chemicals. Use monthly to control buildup.
- Call a plumber if needed – For serious clogs, call in a professional plumber to mechanically clean the pipes and get your drain flowing freely again.
With some careful maintenance and usage habits, tub drains can keep flowing smoothly for years before needing a replacement.
Tub Drain Replacement Cost
If you opt to hire a plumber rather than DIY, here are typical costs for replacing a bathtub drain:
- Drain replacement: $125 – $325, depending on extent of work needed
- Additional charges: $50 – $100 for access issues, rotted subfloor or other complications
- Service call fee: $50 – $100
- Total cost range: $200 – $500+, excluding parts
Having an access panel and shutting off the water supply ahead of time can help reduce costs and speed up the process. Whenever possible, try to complete a drain replacement when remodeling a bathroom for the most affordable pricing.
Bathtub Drain FAQs
Here are answers to some frequently asked questions about replacing and maintaining tub drains:
What tools do I need to replace a tub drain?
A basic tub drain replacement requires a Philips head screwdriver, adjustable pliers or tongue-and-groove pliers, tub drain wrench, propane torch, and sealant like plumber’s putty or silicone caulk. Needle-nose pliers, pipe wrench, reciprocating saw, safety goggles, and rag may also be needed.
Can I replace just the tub stopper?
On simple pop-up or lift-and-turn stoppers, you can replace just the stopper mechanism while leaving the drain in place. This doesn’t require disconnecting from the drain pipe.
How do I unclog a tub drain without chemicals?
Boil a pot of water and carefully pour down the drain to clear soap buildup. Use a zip-it drain cleaner to pull out hair. Flush with boiling salt water (1 cup salt to a quart of water). Or try a plunger to push out debris lodged deep in the drain.
What is the tool I need to loosen tub shoe?
A specialized tub drain wrench with adjustable claws is designed to grip the inside lip of the tub shoe for easy turning. Adjustable pliers or tongue-and-groove pliers can also work in some cases.
How tight should I tighten a tub drain?
Tighten the tub drain shoe by hand first using pliers or a wrench. Finish tightening another 1/4 to 1/2 turn past the point of hand tightening. Don’t overtighten or you can crack the tub – just tight enough to firmly compress the plumber’s putty.
Conclusion
Removing and replacing a worn or damaged bathtub drain is a straightforward DIY project that most homeowners can tackle themselves with some planning and the right tools. Following the steps above for preparing the area, cleanly extracting the old drain, installing new plumbing components and making secure connections will ensure long-lasting results and prevent leakage issues. Pay close attention to properly applying plumber’s putty and adequately tightening fittings to achieve a watertight seal. With some perseverance and elbow grease, you can avoid the hassle and expense of calling in a plumber to replace a tub drain.