How to Install an Adjustable Shower Drain

An Adjustable Shower Drain is Necessary When Installing a Shower Pan Membrane Liner

By Mark J. Donovan

When installing a shower pan membrane liner for a ceramic tile shower, an adjustable shower drain is required.

The adjustable shower drain enables you to adjust the height of the shower drain to the finished height of the ceramic tile shower floor.

To install an adjustable shower drain assembly first disassemble its several pieces.

Install Shower Drain Base and Protect Drain

Next install the drain base into the shower subfloor area and solvent welded it to the PVC shower drain pipe.

After installing the drain base, cover the drain base with duct tape to prevent anything from falling into the shower drain.

Once the drain base has been installed and sealed, you can then begin to build the mortar shower pan.

Building Mortar Shower Pan

To build the mortar shower pan first install a pre-sloped mortar layer such that a ¼” per foot downward slope is created from the shower wall framing to the adjustable shower drain area. 

Adjustable Shower Drain

The pre-slope mortar layer should be flush with the top surface of the drain base.

After the pre-slope mortar has cured, install the flexible shower pan membrane liner. Make sure to cut a hole out for the adjustable shower drain.

The hole should be small enough so that some of the membrane material rides over the drain base. You will also need to cut 4 small holes for the adjustable shower drain bolts. Use a utility knife to cut a small X over each bolt.

Apply a bead of silicone caulk to the top of the drain base, approximately one inch in from the perimeter of the drain base edges.

Then initially thread the adjustable shower drain clamping bolts to the drain base and lay the shower pan liner edge over it.

Next slide the adjustable shower drain clamp bracket over the bolts and then rotate the bracket counter clockwise.

You may also need to tighten the screws.

Shower Pan Membrane Liner eBook

Learn how to install a mortar shower pan with this eBook.

Adjusting the Shower Drain Barrel

Next screw the adjustable shower drain barrel and screen into the drain assembly. Adjust it to the expected finished height of the shower pan. You will need to account for approximately 1-1/4” to 1-1/2” of additional reinforcement mortar and the thickness of the ceramic tile.

After adjusting the height of the adjustable shower drain barrel, install backer board material on the shower wall framing to one inch above the pre-slope mortar level.

Next, place some small gravel pebbles or small chips of broken tile around the weep holes of the adjustable shower drain. This will prevent the reinforcement mortar layer from clogging the weep holes.

Finally, pour your reinforcement mortar into the shower pan area to cover the shower pan membrane liner. The mortar should cover the bottom edge of the backer board and come to approximately ¼” height (Ceramic tile plus thin set mortar thickness) of the top of the adjustable shower drain barrel and screen.

This will allow space so that the ceramic tile will be flush with the top of the adjustable shower drain.

Once the reinforcement mortar has cured you can begin to tile your ceramic tile shower.

For information on installing a shower pan membrane liner for a ceramic tile shower, see the Shower Pan Membrane Liner Installation eBook from  The Shower Pan Membrane Liner EBook will quickly teach you the step-by-step process for installing the shower pan membrane liner correctly. It includes instructions on framing the shower stall, pouring the pre-slope and shower base mortar, and installing the shower pan membrane liner.

Shower Pan Membrane Liner Installation eBook

For information on how to tile a custom ceramic tile shower, see the “How to Tile a Custom Ceramic Tile Shower eBook” from This eBook will quickly provide you with step-by-step instructions on how to measure and install ceramic tile in a shower, including the installation of tile on shower walls, floors and curbs. It provides detailed instructions for every step in the process of tiling a custom ceramic tile shower and is loaded with instructional pictures!

Related Information on Tiling Showers and Installing Mortar Shower Pans

Additional Plumbing Resources from

Get Free Bathroom Remodeling Price Quotes with No Obligation!

Fill out our 3-5 minute quick and easy form, and receive a free price quote on a bathroom remodeling project from one of our pre-screened and licensed bathroom remodeling contractors. This process is free and there is no obligation to continue once you receive your bathroom addition price estimate.