The flange is the part of the drain that can be visibly seen in the tub. You might also hear it called a drain basket. 

It’s actually not too hard to DIY a drain flange replacement as long as you know where to start.

Make sure you understand how your tub’s drain system works. A flange is threaded to the elbow of the drain to keep the plumbing together. 

It is also sealed to the surface of the tub with plumber’s putty to prevent leaks.

Tools and Supplies You Will Need to Replace the Flange

Before you get started, make sure you have:   

  • A drain key
        
  • A wrench
        
  • A container or bucket
        
  • Plumber’s putty
        
  • Putty knife
        
  • A flathead screwdriver (for removing the stopper; might not be necessary)

The drain key is used to remove the flange. It’s vital that you have some kind of specialized drain removal tool, as this will make your job a lot easier.

12 Steps to Replace a Bathtub Drain Flange

Step 1. Take the stopper out

The method to remove the stopper will vary depending on your bathtub model. You may need a flathead screwdriver or a pair of pliers, but it should be relatively simple.

When you take the stopper out, you might find grime and hair stuck to it. That’s why you need a container on hand to hold the grungy parts. It keeps the messiness from tracking all over your floors.

Step 2. Use your drain key

Your drain key is a tool made specifically to unscrew drains. It should have come with a manual that has instructions for proper use. Make sure you comply with all of the instructions and safety guidelines.

Insert the key into your drain and turn it counterclockwise to begin uninstalling the drain. After a few turns, the drain should be unscrewed well enough that it pops out of the hole without any issue.

Step 3. Clean

Before you put a new flange in, you need to clean the drain opening. In addition to getting rid of the hair and grime from the stopper, you’ll need to scrape up any putty residue from the first flange.

It’s also important that the area dries out before you start installing the new component. You might use a towel to speed the process, once you’ve removed all the gunk and putty from around the hole.

Step 4. Check the gasket 

The rubber gasket is the part of the drain that makes a seal at the elbow, preventing leaks in the plumbing. You need to check the gasket and make sure that the seal is still watertight. In addition, evaluate the gasket for damage or wear. If it is worn down, it must be replaced.

Replacing the gasket is fairly simple, as long as you have all of the components:

  • Pry the old piece out with a flathead screwdriver.
        
  • Be careful not to move the elbow of the drain, as misalignment can cause a major headache.
        
  • Take your new gasket and squeeze it alongside one side of your drain.
        
  • Once this is done, push your gasket’s other side into the right position.

If you do need to replace the gasket, it’s easiest to do when the flange is already open like this.

Step 5. Apply plumber’s putty

Now it’s time to get your plumber’s putty out. You should roll it in your hands until you have a long piece that’s around the width of a pen.

Wrap your pencil strip around the underside of the new flange, all the way around the circumference of the lip. 

It should be strong enough to circle the whole thing. If there are any gaps in the putty, you won’t get the watertight seal that you need.

Step 6. Begin reinstalling the flange

Now you’ll put a new drain flange or the cleaned old drain flange back in the hole. The putty should align with the surface of the tub when the lip catches on the edges.

To start threading it to the elbow properly, give the drain a slow clockwise turn. You want to be careful and precise with your movements because otherwise, you might cross-thread the components. 

If that happens, you’ll have to install the flange all over again.

With some plumbing applications, you have to use thread sealers to thread two components together. 

But since there’s a gasket attached to the drain, you don’t need to worry about it here. The gasket seals the flange to the elbow without the need for extra sealers.

You don’t need to connect all the threads here! Just connect the first couple to get started.

Step 7. Tighten with the drain key

Now that some of your threads are connected, you can use your drain key to tighten the flange. Turn it with your hand until it feels tightly sealed into the drain elbow. 

After this, you’ll take your wrench and tighten the drain by turning it one more quarter.

It’s important to use care during this step. If you over-tighten the flange, you might break your putty seal or crack your tub. 

Working too quickly can also misalign your gasket, which might cause leaks underneath the tub where the flange and elbow meet.

At the same time, it is important for the drain to be tight enough not to leak. The putty seal around it should help with that.

Step 8. Remove excess plumber’s putty

When you tighten the flange against the surface of the tub, extra putty might squeeze out around the sides. 

Once you have that tight seal, you can run a putty knife around the edges to pull up the excess. This can be put away and used again the next time you need a plumber’s putty.

Saving the excess putty helps to reduce waste and improve your efficiency.

The plumber’s putty doesn’t require any time to dry or harden, you can use the drain right away.

Step 9. Put the tub stopper back

Again, the process for doing this will depend on your bathtub model. But it should be essentially the reverse of how you uninstalled the stopper.

Step 10. Run the water

Plug the tub fully and run the water. The putty around the drain should be fully resistant to the water since it doesn’t need to dry. Doing this will let you double-check that there aren’t any leaks around the lip of the flange or around the stopper.

You can even take a bath if you want to reward yourself for a job well done.

Step 11. Correct any leaks 

If there are any leaks, you’ll need to identify the source. It might be the seal of the flange, the drain stopper, or the gasket. You must correct these right away to keep from wasting water and causing potential structural damage below your tub.

Step 12. Relax

Once your tub is leak-free, you can relax. You’ve done it! The process isn’t particularly hard as long as you understand how your drain system fits together.

Conclusion

Replacing a bathtub drain flange is a fairly straightforward home improvement project, so you shouldn’t need to call a handyman, although it can seem intimidating if you’ve never done it before. 

All you have to do is remove the old flange and install the new one. That means hooking it to the appropriate parts of the drain assembly and sealing it around the tub.

The biggest part of the battle is understanding how your drain works. 

Once you have a good sense of how the flange and elbow thread together, how the gasket seals the drain, and how the putty seals the exterior, the step-by-step process only takes a few minutes.