The Ultimate Guide To Installing A Shower Pan

A shower pan is an essential part of any shower, as it prevents water from pooling around your feet. Shower pans are usually made of durable materials such as porcelain, ceramic, or fibreglass, and they can last anywhere from 10 to 45 years. While it is possible to create a shower floor using a pan liner and tile, a ready-made shower pan is easier to install. In this article, we will discuss the steps to install a shower pan, the different types of shower pans available, and how to fix a leaking shower pan.

Test-fit the shower pan

To test-fit the shower pan, you must first dry-fit the shower pan in the opening. Draw a line onto the subfloor along the edge of the shower pan; this line will be referenced later. Check to see if the shower drain hole lines up with the existing shower drain. If the hole does not align, trace the hole location onto the substrate and remove the shower pan.

Using a jigsaw or circular saw, cut a hole in the subfloor for the shower drain pipe. The size of this hole typically shouldn’t exceed 5 inches, but check with the shower pan manufacturer’s specifications. Relocate the P-trap for the shower drain and pipe as necessary from below so that the waste pipe extends approximately 1 3/4-inch above the subfloor (this distance will be specified in the manufacturer’s instructions).

The entire bottom of the shower pan needs to sit on a flat, level surface. Check the subfloor area from left to right and from front to back to make sure it's level. If the subfloor is not flat and level, apply a self-levelling compound following the manufacturer’s instructions. Be sure to use a self-levelling compound that adheres to the substrate you are installing it over (OSB, cement board, plywood, etc).

Run the self-levelling compound up to the line you drew earlier. Screw a piece of 1x2 along the line to act as a dam if necessary. This will keep the self-levelling compound contained within the shower pan area. Allow the self-levelling compound to cure per manufacturer’s instructions.

Now, test-fit the shower drain flange, also known as the "drain basket" or "drain body", to ensure it fits flush with the shower base. Line the underside of the shower drain flange’s rim with latex/acrylic or silicone caulk, per manufacturer’s instructions. Place the flange through the top side of the shower pan and press down as far as you can without twisting so that the excess caulk squeezes out. Wipe away excess caulk before it dries.

On the underside of the shower pan, put the rubber washer around the threads of the flange and against the bottom of the shower pan. Next, put the friction washer (which looks like a cardboard version of the rubber washer) on the threads of the flange. Screw the locking ring onto the threads of the flange, tightening the gasket and friction washer between it and the bottom of the shower pan. Use adjustable pliers to tighten if needed.

Prepare the subfloor

Before installing the shower pan, the subfloor needs to be in good shape. If there are any signs of mould, damaged plywood, or rot, it’s important to take care of that first. Also, check for any lumps and bumps that the shower’s space might contain.

Use a tape measure and pencil to measure and mark the locations of the feet on the subfloor. Then, use shims placed on the shower floor to create a level space for the pan. Composite shims are best for this since they are impervious to water and have greater load-bearing capacity.

If the shower pan does not have supports, it will require a bed of mortar mix. The mortar will eliminate the need to shim the pan.

The entire bottom of the shower pan needs to sit on a flat, level surface. Check the subfloor area from left to right and from front to back to make sure it's level.

If the subfloor is not flat and level, apply a self-levelling compound following the manufacturer’s instructions. Be sure to use a self-levelling compound that adheres to the substrate you are installing it over (OSB, cement board, plywood, etc).

Run the self-levelling compound up to the line you drew in step 1. Screw a piece of 1x2 along the line to act as a dam if necessary. This will keep the self-levelling compound contained within the shower pan area.

Allow the self-levelling compound to cure per manufacturer’s instructions.

Install the shower drain flange

To install the shower drain flange, also known as the "drain basket" or "drain body", you will need to follow these steps:

First, test-fit the shower drain flange to ensure it fits flush with the shower base. Then, line the underside of the shower drain flange's rim with latex/acrylic or silicone caulk, following the manufacturer's instructions. Place the flange through the top side of the shower pan and press down as far as you can without twisting, so that the excess caulk squeezes out.

Next, wipe away any excess caulk before it dries using an old cloth or paper towel. On the underside of the shower pan, put the rubber washer around the threads of the flange and against the bottom of the shower pan. Then, put the friction washer (which is like a cardboard version of the rubber washer) on the threads of the flange.

Finally, screw the locking ring onto the threads of the flange, tightening the gasket and friction washer between it and the bottom of the shower pan. Use adjustable pliers to tighten if needed.

If you are installing a compression-style shower drain, the drain fitting is normally installed into the shower base before the base is laid into position. The drainpipe should come up to about 3/4 to 1 inch below the lip of the shower drain, following the manufacturer's recommendations. You may need to test-fit the shower base to mark the right height, then remove the base to cut the pipe.

Apply a bead of silicone caulk or plumber's putty around the top flange of the shower drain opening, then insert the drain assembly into the opening. Put the rubber sealing washer and cardboard friction washer over the drain assembly tailpiece from under the shower base. Thread the mounting nut onto the tailpiece and tighten it with channel-lock pliers. Wipe away any excess caulk that has oozed out around the drain assembly.

Secure the shower pan

To secure the shower pan, you will need to follow the manufacturer's instructions. Some manufacturers will require the shower pan to sit directly in an adhesive, while others will call for small mounds of mortar.

If adhesive is called for, spread it within the area where the shower pan will sit. Position the shower base in the area, placing it onto the adhesive, and press firmly in place.

If mounds of mortar are called for, mark the locations on the subfloor per the manufacturer's instructions. Then, position mounds of mortar on the marks. Place the shower base in the area, pressing it firmly in place.

Adjust the shower pan until it is level in all directions. Place cardboard or another material into the shower pan base to protect its surface. Screw the shower pan rim into the wall studs using 1 1/4-inch exterior-grade screws through the pre-drilled holes.

Attach the gasket and drain screen

Attaching the gasket and drain screen is a crucial step in ensuring your shower is watertight. Here's a detailed, step-by-step guide on how to attach the gasket and drain screen for a shower pan installation:

Step 1: Place the Rubber Gasket

Place the rubber drainpipe gasket over the drainpipe that is protruding through the shower drain flange. This gasket will create a watertight seal, preventing any leaks.

Step 2: Thread the Gasket Setscrew

Take the gasket setscrew and carefully thread it over the rubber gasket. This will secure the gasket in place.

Step 3: Tighten the Setscrew

Using the included tool and a screwdriver, tighten the gasket setscrew until it feels secure and snug. Make sure to follow the manufacturer's instructions for the appropriate level of tightness.

Step 4: Attach the Drain Screen

Now, you'll want to attach the shower drain screen. Depending on the specific model, you may need to screw or snap it into place. Ensure that the drain screen sits flush with the shower pan base for a seamless finish.

Step 5: Allow the Adhesive to Dry

Before proceeding, it's important to let the thinset mortar or adhesive dry completely. Follow the manufacturer's instructions for the recommended drying time.

Step 6: Test for Leaks

Once the adhesive is dry, it's time to test your work. Test the pan and shower drain connection for any leaks. This is a crucial step to ensure that your installation is successful and watertight. If leaks are detected, make the necessary adjustments and re-test. If you're unsure, consider getting a professional inspection.

By carefully following these steps, you can effectively attach the gasket and drain screen for your shower pan installation, ensuring a watertight seal and a functional shower drain. Remember to always refer to the manufacturer's instructions and take your time with each step for the best results.

Frequently asked questions