Shower Drain Seal Replacement – A Comprehensive Step-By-Step Guide

Shower drain seal replacement is not a job for the faint of heart, but it can be completed by an average homeowner. This guide will walk you through the entire process step-by-step.

Start by removing the metal drain cover. Screws are usually used to hold the cover in place, so save them and put them somewhere safe.

1. Remove the Drain

The drain cover usually has screws in it, or prongs that hold it in place. Use a utility knife to remove them.

Apply a bead of silicone caulk around the shower drain opening. Set the upper body of the drain assembly into the drain opening and press down. Slide a rubber sealing washer and cardboard friction washer over the tailpiece. Tighten the locknut from underneath and wipe away any excess caulk or putty.

2. Remove the Liner

Typically, the drain flange is sealed to the shower base with plumber’s putty. It’s important to use enough material to create a strong seal that prevents water from seeping through the shower wall and into the home.

Alternatively, you can also use a WingTite Drain, which can be installed from above without cutting open the finished ceiling. It’s a great option for preventing mold and mildew build-up in the ceiling.

3. Remove the Drain Flange

If the leak is coming from the shower drain, it’s likely because the seal at the lower part of the flange has broken. You can repair this by packing plumbers’ putty on the flange’s underside – rolling it into a rope and then flattening it with your fingers.

The flange has a male-threaded outlet that fits over the waste pipe. A rubber gasket and a locknut hold the assembly in place.

4. Remove the Drain Body

To keep the shower drain functioning properly, the membrane must be sealed to the pan. Use a caulk that’s designed for this purpose.

Be sure to buy a kit that contains the entire drain assembly. This will make the job much easier. Before applying the caulk, remove any screws from around the drain opening. This will prevent them from falling into the open drain and causing a clog.

5. Remove the Compression Gasket

If you have a type of shower drain that screws into place (like this Oatey 2-Inch PVC No-Calk Shower Drain) rather than solvent welds or attaches with a nut, you can replace it without cutting through the ceiling. Just make sure the new drain you choose is compatible with your current setup.

Start by wedgeing a screwdriver under the strainer so you can pry it up and expose the locknut. Remove the locknut and the friction washer and sealing washer.

6. Remove the Locknut

The large plastic lock nut (Photo 2) holds the drain basket tight to the shower tank. Spray the nut with penetrating oil, then use a strap wrench or spigot wrench to loosen and remove it.

If the nut is still stuck, lubricate it with a rag or towel soaked in hot water. Heat or a calcium dissolver may also help. Alternatively, try using a nut splitter.

7. Remove the Liner

A leaking drain can damage the ceiling below it, leaving water spots and mold. This often happens because a shower liner is attached with construction adhesive to the ceiling and not screwed into the studs.

Plunge the drain to dislodge a clog or pour boiling water down the drain to remove soap scum or clumps of hair. Clean the rim of the drain opening and wipe away any plumber’s putty.

8. Install the Liner

Before you install the liner, you should use a mortar bed that is sloped to match the height of the drain’s weep holes. You can build this with mortar or by using a product like Oatey Perfect Slope.

Be sure to place washed pea gravel over the weep holes to prevent them from getting cemented shut. Also, cover the drain opening with duct tape.

9. Install the Drain Body

The shower drain carries waste water away from the shower pan and prevents unwanted odors. If the drain clogs, you may need to clean it using baking soda and vinegar.

Before installing the new drain body, apply a thick bead of silicone caulk around its flange. This will help ensure a watertight seal. Allow the caulk to cure completely before continuing with the installation.

10. Install the Compression Gasket

To ensure a watertight seal, apply a thick bead of plastic pipe primer and then a thin coat of solvent glue around the outside of the drain flange. Then, slide the lower body of the shower drain over the upper body and tighten the outer locknut until silicone oozes out between the flange and the shower base.

This section of the repair requires that you cut into the ceiling or shimmy into the crawl space beneath your bathroom (depending on where the shower is located). Wear a mask.