How to Install a Shower Pan in 6 Simple Steps

Eventually, most homeowners need to remodel their bathrooms. This process takes much thought and consideration, especially if the bathroom is only big enough to accommodate a walk-in shower instead of a full bathtub.

At the bottom of the shower is a component that not many people know about: the shower pan. This crucial surface protects your subfloor from water damage by helping the shower drain properly.

The shower pan is a waterproof floor covering commonly made from acrylic, fiberglass, or tile. It has a gentle slope, allowing the water to flow toward the drain. When the shower floor pan is properly installed, it helps prevent mold and mildew growth by reducing standing water.

When you’re learning how to install a shower pan for a DIY bathroom remodel that includes replacing your shower, you only need basic plumbing skills to install the new component. But it’s essential to follow the step-by-step guide and not cut corners. A mistake can lead to the failure of the entire shower.

Before beginning the project, you want to correctly measure the space to ensure your shower pan installation goes smoothly. You must use a tape measure to get the space's accurate length and width. These measurements will help you purchase the right size pan.

Then, you’ll clean the area. You need to place your shower pan on a level surface, so you must remove debris from the bathroom floor. Sweep up loose particles with a vacuum or broom. Then, use a putty knife or paint scraping tool to remove old caulking or adhesive. It’s also a good idea to clean your shower walls and remove anything that could get damaged during the installation.

Ensure the entire surface is free of standing water before installing the tray. Wet surfaces create a home for mildew and mold. They also interfere with caulk, giving you a defective seal before you even use your shower.

The Difference Between a Shower Pan and Base

Some homeowners may use the terms “shower pan” and “shower base” interchangeably. However, this is a mistake because they are very different pieces.

A shower pan and a shower base are similar in that they both direct water toward the drain. The primary difference between these two components is their location. The shower pan functions as the shower floor, while the base is underneath the pan and protects the subfloor. In most shower remodels, you will typically choose either a shower base or a shower pan, since you don't necessarily need both. The choice between the two depends on your specific needs for customization, installation skill level, budget, and project timeline.

1. Test-fit the Shower Pan

Before doing anything with your shower pan, open the package and inspect it for damage. If you start the job with a faulty product, your finished project won’t work as intended.

When you’re learning how to install a shower pan, it’s best to have someone help you. One of the first things you must do is dry-fit the shower floor pan into the opening. This step serves two purposes: to allow the DIYer to decide whether to remove the drain piping and to verify the pan is sitting level.

Dry-fitting is done without any adhesive. You want to ensure everything fits snugly within the space. However, it must not be too tight, or it could cause the pan to buckle. If it fits too loosely, the pan could move and cause the seams to separate. This issue leads to water seeping into the base.

Do a test fit by creating a line on the subfloor near the edge of the shower pan. This marks the height of the pan flange on the wall stud. You will need this line later for a reference point.

Using a power drill, place 3/16-inch holes into the flange near each stud. Line up the drain holes where the existing shower drain is positioned. You may have to outline where the holes sit within the shower drain on the substrate.

Before cutting, refer to the manufacturer’s instructions for how big these holes should be. Once you have the right size, make a hole in the subfloor with a jigsaw. This hole is for the drain pipe. The most common size for this hole is under five inches, but refer to the manufacturer’s specifications for your shower floor pan.

It’s not always necessary, but some projects require you to move the P-trap for the shower drain. This ensures the waste pipe extends about 1 3/4 inches above the subfloor, or to the distance in the manufacturers’ specifications. Moving a P-trap can be challenging, so if you feel like you’ve taken on more than you can handle, call an expert before moving on.

2. Prepare the Subfloor

Your subfloor must be in good condition before you begin the installation. If there is any wood rot or damage, you must repair those areas first.

Some shower pans have feet. If yours does, pay attention to where the feet should go. If your pan does not have feet, you’ll want to use a bubble level to verify there are no slopes.

Ensure the bottom of the shower floor plan sits on a level surface. Inspect the area to verify that it is flat. If it is, you can begin installing the shower drain flange.

If the subfloor is not level, you must complete an additional step: Use a self-leveling compound that sticks to the material you are installing it over. For example, verify the compound adheres to the cement board before applying it to the surface.

Position the self-leveling compound up to the line you drew during your test fit. Place another material, such as a 1x2 board, in front of the line to prevent the compound from running out of the shower floor pan area. Allow it to cure according to the manufacturer’s instructions.

3. Install the Shower Drain Flange

It’s time to test-fit the shower drain flange. You may also hear this component called a “drain body” or “drain basket.” Remove it from the box and separate the parts.

Make sure it fits flush along the shower base. Line the bottom of the shower drain flange’s rim using an acrylic, latex, or silicone caulk. Read the manufacturer’s instructions to make sure your material is compatible.

Some homeowners use plumber’s putty, which is a drain flange sealant. However, this putty may cause the shower floor pan material to degrade. Using the wrong product will affect your shower pan down the line.

After applying the sealant, place the flange through the top of the new shower pan and apply pressure. Allow the flange to go down as far as it can to allow any excess caulk to flow out. Remove the extra material before it dries.

On the bottom of the shower floor pan, put the rubber washer around the flange’s threads and against the underside of it. Follow this with the friction washer on the flange threads. Screw the locking ring into the flange’s threads and tighten the components using adjustable pliers.

Remember that all drain assembly kits will vary by manufacturer. Follow the instructions for your specific kit before securing your shower drain.

4. Secure the Shower Pan

Every manufacturer has different recommendations for its products. For a shower pan installation, your product might require the pan to sit directly on an adhesive or on small piles of thin-set mortar.

If your shower pan installation requires an adhesive, spread it throughout the area where it will be placed. If the mortar is needed, identify the locations on the subfloor according to the manufacturers’ directions. A 50-pound bag of thin-set mortar is suitable for most projects that range between 45 and 50 square feet.

Mix the material according to the instructions and level it with a towel. It should be about the consistency of peanut butter — pourable but thick enough that it won’t run off the surface.

Spread the mortar or other adhesive in an even layer within the area around the shower pan’s intended position. Fill any voids on the floor to help the pan sit level. Add a shower pan Oatey liner between the mortar and subfloor for extra waterproofing. Don’t fill the entire subfloor with the mixture, or there won’t be enough space under the pan to compress it.

Carefully place the shower base into the adhesive or mortar and press firmly. Ensure the shower floor pan is level in all directions, making adjustments as needed. Place a protective layer, such as cardboard, into the shower pan to protect the surface, and screw the rim in the other wall using 1 ½ - 2 inch screws. These screws will go through the pre-drilled holes to attach the rim of the pan to the wall studs.

5. Attach Gasket and Drain Screen

Next, you’ll need to place the rubber drain pipe gasket over the drain pipe rising through the shower drain flange. Secure the gasket set screw over the rubber gasket and tighten. Snap or screw the shower drain screen over the flange, ensuring it sits tightly against the shower pan base.

6. Test for Leaks

After successfully fitting the pan, reassembling the drain pipe, and connecting all parts, it’s time to inspect it for leaks. Before testing your shower pan installation, you must let the adhesive or mortar dry according to the manufacturer’s instructions. This may take between 24 and 48 hours.

Once everything is dry, test the newly installed components for leaks. Look in and around the shower stall.

It’s also helpful to plug the drain while the water runs, then stop the water to see if the level is steady. This will help you identify whether your shower pan installation is leaking.'

When It’s Time to Replace Your Shower Floor Plan

If a shower pan is correctly installed, it should last 10 or more years. However, you’ll know it’s nearing the end of its life because it will begin breaking down. You can prevent your subfloor from getting damaged by watching for signs of wear.

Signs that it’s time for a new shower floor pan include:

• Water spilled onto the bathroom floor
• Visible cracks
• Movement in the pan
• Moisture stains on the ceiling or walls

If you notice buckling, your subfloor may already be damaged because of a leak or crack that went unnoticed. Don’t delay replacing your shower pan because these issues will not get better!

What’s the Average Cost of a Shower Floor Pan Replacement?

How much you pay for your project varies based on several factors. Regardless of your budget, you’re sure to find something that will fit within your limit. These are a few key factors to consider:

Size

Many showers are available in standard sizes, such as 32 by 32 inches. A square walk-in shower pan will cost less than a shower-tub combo that requires more space. However, if your shower isn’t a standard size, your cost will increase because a custom pan must be made for your bathroom.

Type of Material

Although numerous shower pan materials are available, the most cost-effective option is fiberglass, which isn’t as durable as other materials. Acrylic shower pans are lightweight, durable, and relatively inexpensive.

The most significant investment would be a tiled shower pan. However, they require more maintenance, including resealing the surface. These materials give your bathroom a stunning, high-end appearance.

Demo and Removal

When you’re ready to replace a shower pan, it will take time and money to remove the old one. You may also have to pay a disposal fee to have someone remove it.

Another cost to consider is plumbing. Will you need new plumbing installed, or will your existing system work?

Labor

If you install the shower floor pan yourself, you won’t have to worry about labor fees. A shower pan installation typically takes one day to complete. However, the time varies based on whether new plumbing must be installed and whether other adjustments are needed to accommodate the shower pan.

Shower Base Replacement

Replacing your shower base is ideal after your shower pan leaks. Water from the pan may have damaged your base.

Drain Location

Your drain often goes unnoticed, but it is a pivotal point. A shower drain connects with your home’s plumbing, so where it sits impacts the type of shower pan you can invest in. If the layout does need altering, it’s best to hire a professional, which will add to the cost.

Accessibility Features

You may be remodeling your bathroom to create a more accessible shower. Accessible shower pans are more expensive but have features like slip-resistant flooring. This type of shower pan keeps those who use a wheelchair or walker safe.

New Shower Door

A new shower door also adds to the cost of your home improvement project. You can choose from the following door options:

• Swinging
• Sliding
• Corner

While you can create a shower with no doors, you may want to add more drains.

Permits

If your town requires permits for a shower pan installation, you must secure these. Check with your local permit office to learn more. You may be required to pay a one-time fee or a daily fee.

Other Extras

You can add many other features while you’re working on your bathroom remodel and shower pan replacement. Shower pans can be painted with epoxy paint specially made for showers and bathtubs. This paint gives you more control over the color of your walk-in shower.

You can also include a new bath fan with or without light and heat. These details may require the help of a contractor who can give you an estimate for any additional features.

More on How to Install a Shower Pan

Learning how to install a shower pan may seem complex. There are lots of steps involved, and attention to detail is crucial. However, with the right technique, quality products, and a little knowledge, you can install your shower floor pan DIY.

Some homeowners need a custom-made pan, which may complicate the process because there are no standard directions. Prefabricated shower pans are easy, quick, and less likely to have complications throughout the project.

Follow the step-by-step instructions provided by the manufacturer and use the included clips or screws to attach the pan to the flange and wall studs.

One of the most crucial steps is ensuring that your floor is level and supported. This prevents leaks and ultimately prolongs the life span of your shower pan.

Although many homeowners complete this DIY project, you may benefit from hiring a professional installer. They can ensure that your floor is level and that you have proper draining. Your shower pan installation will likely go much faster if you rely on the skills and knowledge of a licensed plumber.