How to Install a Stopper Drain Fitting in a Bathtub

Replacing a tub shoe for one with a stopper
Aaron Stickley
Overview
  • Total Time: 30 mins
  • Skill Level: Beginner
  • Estimated Cost: $30 to $50

A tub tub drain with a built-in stopper has distinct advantages over other types of drains. They are more durable and easier to maintain than pop-up stoppers that operate by linkage running through the overflow tube. And if you have an old-style tub with a rubber stopper held by a chain, a built-in stopper drain fitting will modernize your fixture. 

By replacing a tub shoe for one with a stopper, you can be sure that the stopper will always be in place and operating when you need it.

What You'll Need

Equipment / Tools

  • Tub drain wrench (dumbbell tool)
  • Channel-type pliers
  • Putty knife

Materials

  • Tub drain converter kit for a stopper drain
  • Plumber's putty

Instructions

  1. Get the Right Tool and Fitting

    If you don't already own one, spend a few dollars on a tub drain wrench, also called a dumbbell tool. This specialty tool makes quick work of the otherwise laborious job of unscrewing the drain fitting from the tub shoe below the tub. Tub drain wrenches usually have two ends for different sizes of drain openings. The end fits into the opening and keys into the crosshairs of the drain strainer. Then you turn the tool with pliers to loosen the drain fitting. If your drain doesn't have crosshairs, you need a variation on the drain wrench called a drain extractor.

    Also be sure to the get the right size of drain fitting for your tub shoe. If you're not sure of the size of your tub drain, you can buy a kit that can be adapted to two drain sizes.

    A tub shoe kit and dumbell wrench
    Aaron Stickley
  2. Remove the Old Bathtub Drain Fitting

    Use the tub drain wrench to remove the existing drain fitting from the tub shoe. First, determine which end of the wrench will fit inside the drain opening and around the drain fitting's crosshairs. Insert the wrench into the tub drain and align it with the crosshairs, then use channel-type pliers or an adjustable wrench to rotate the drain fitting counterclockwise and loosen the fitting. It will unthread from the tub shoe below the tub. Keep turning until the fitting comes free.

    Dumbell wrench removing a tub shoe
    Aaron Stickley
  3. Clean the Tub Drain Opening

    Pull the fitting from the tub, and clean off the ring of plumber’s putty that surrounds the opening of the tub drain. It is best to have a clean surface to work with, so be sure to remove as much of the putty as possible. If the plumber’s putty is dried in place, you can use a non-scratch scouring pad to remove it.

    Clean putty off of drain opening
    Aaron Stickley
  4. Determine the Drain Thread Size

    Use the old fitting to determine the size of your drain. A bathtub drain converter kit provides drain threads in two sizes to accommodate different tub drains. Select the appropriate thread attachment.

    Tub Shoe Threads
    Aaron Stickley
  5. Install the New Tub Drain Fitting

    Remove the tub stopper from the new drain fitting. Apply a generous band of plumber’s putty to the bottom of the flange on the new fitting. Insert the fitting into the bathtub drain opening, making sure to center it.

    A good way to avoid cross-threading is to start tightening by hand first. When it looks like the fitting's threads have started, you can continue tightening by using the tub drain wrench. Make sure to thread the fitting into the drain plumbing carefully. 

    Lastly, clean off any excess plumber’s putty from around the drain fitting, then insert the stopper.

    Install a new tub shoe
    Aaron Stickley