How to Install a Shower Pan: A DIY Guide

Building and installing a custom shower floor used to take hours if not days. For the ordinary DIYer, the task might even be too much to handle. Hiring a professional may even cost thousands of dollars. 

Now, with so many prefabbed shower pan options, installing a shower floor is just a short day worth of work. Prefabbed shower pans are easier to install and are an affordable way to remodel your shower floor. 

In this article, we’ll give you all the steps you need to install a shower pan for your bathroom remodel.

Materials and Tools Needed

• Pencil
• Hammer
• Level
• Drill 
• Mixing paddle
• Roofing nails or 1-1/4 screws
• Trowel
• Bucket
• Self-leveling underlayment
• Drain kit (if not included with pan)
• Silicone caulk and caulk gun
• Channel-lock pliers
• Hacksaw
• Mortar/adhesive

Step 1: Subfloor Prep

For your shower pan to drain properly, the subfloor in which the pan will sit on top of needs to be level and in good condition. If the subfloor needs to be replaced, remove it, and install new subfloor grade plywood.

Use your level to check for any low or high spots. If the subfloor is not level, seal the plywood with a wood sealer. Then spread a self-leveler over the low spots and feather edges. 

NOTE: Before any subfloor preparation is started, it is good to inspect and see if there is any preexisting water damage or mold in and around the shower base.

If signs of a water leak are visible, call a professional to help with your shower pan restoration. 

Step 2: Make Sure Shower Pan Fits

We assume that you’ve already measured and ordered a shower pan that fits your shower’s rough opening. However, it’s best to dry-fit test your shower pan before proceeding.

So make sure the subfloor is level and clean, and set in the pan.

Check and see that the drain pipe fits correctly inside the pan’s drain opening. If the drain pipe doesn’t align with the drain opening, you’ll need to call a plumber to add or take away piping.

Once you have the pan sitting level inside the shower, take a pencil or chalk line, and mark the perimeter.

Then take a pencil and mark the center of each wall stud on the rim of the pan. Next, pre-drill holes where you’ve marked stud centers on the pan’s rim. These holes will be used to attach the pan to the wall studs with screws later.

Remove the shower pan after making sure everything is the right fit. 

Step 3: Install the Drain Flange

Now test-fit the drain flange to ensure it sits flush with the shower base.

The stub out pipe should be about 1/4″ above the floor to fit the flange.

If the stub out (drain pipe) is too high, cut it with a hacksaw. If it isn’t high enough to fit in with the drain flange, add an extension to it.

Make sure never to force the drain pipe into place. Forcing a drain pipe into place can damage the pipe and lead to leaks in the future.

Now follow the manufacturer’s instructions on how to properly install the drain kit.

Most instructions will have you line the underside of the drain flanges rim with silicone caulk before placing the flange through the topside of your shower pan drain hole.

Next, you’ll press the flange as far down as you can without twisting. You’ll notice excess caulk being squeezed out of the sides from the pressure. That’s fine.

Just wipe away the excess caulk before it dries with a damp towel or rag.

On the underside of the pan, you’ll place a rubber washer around the flange threads, and then a cardboard friction washer on top. Screw the locking ring onto the threaded flange.

Make sure to grab your channel locks to secure the locking ring.

Step 4: Secure the Shower Pan 

Now comes the fun part. Mix your mortar in your bucket to a consistency of peanut butter. You want the mortar to be pourable yet thick enough that it doesn’t run off your trowel.

Now with a notched trowel spread the mortar, or recommended adhesive, within the perimeter that you drew around the shower pan when you were dry fitting. If you’d like extra water-proofing, you can add a shower pan liner between the subfloor and layer of mortar.

You want a nice and even layer of mortar. If it is not spread out evenly, the base of the pan will not sit right.

Next place the shower pan on the mortar, making sure the pre-drilled holes on its rim line up with your wall studs.

Press the pan firmly into the mortar. Check with a level and make adjustments until the entire base is level. 

Lastly, use your roof nails or screws to attach the rim of the pan to your wall studs.

Step 5: Final touches

You’re almost there! But before you start the last few steps of installing a shower pan, we recommend letting the pan sit for 24-48 hours so the mortar has time to dry.

Once the mortar is dry, you can finish putting on the drain pipe gasket and drain screen. Once the rubber gasket and sets screw is in place and tightened, screw or snap the drain screen into place so that its flush with the shower pan.

Now you can check your work and see if there are any leaks. Let’s hope not!

How to Install a Shower Pan? Now You Know

You now know how to install a shower pan! 

Your next move will be to decide what the walls are going to be—Ceramic? Italian marble? Slatestone? Whatever you chose will no doubt look incredible with your newly self-installed shower pan.

For more tips and tricks on home maintenance, keep browsing our blog!