So, You Want to… Install a Shower Pan

Whether you're planning on adding a shower, replacing a bathtub with a shower, or just fixing up an existing shower, you'll need a new shower pan. Here, learn the basics of selecting and installing a new pan, whether prefab or custom.

BySteffaniCameron | Updated Sep 30, 2020 10:26 AM

Photo: wayfair.com

The shower pan is an unsung hero in cramped bathing quarters that rely on a walk-in shower instead of a full-size bathtub. Its role? Protecting your subfloor from water damage by aiding drainage. This waterproof floor covering—often made of fiberglass, acrylic, or tile—slopes just enough to direct water toward the drain in the floor, thus eliminating most problems caused by lingering water, from mold and mildew growth to structural issues like wood rot. Whether you’re remodeling a bathroom to include a shower pan where none existed before or replacing one that’s seen its day, basic plumbing skills and a free weekend are all you need when learning how to install a shower pan.

Why Switch to a Shower?

Many homeowners choose a shower (and thus a shower pan, because you can’t have one without the other) over a bathtub when renovating in order to increase the available floor space and make the bathroom feel larger. Walk-in showers tend to be sleeker in style than boxy or bulky bathtubs, and the glass walls that often enclose them contribute to an airier, less crowded aesthetic. And when it comes to actual dimensions, a shower pan can be as narrow as 27 inches, making it much easier to squeeze into a floor plan than a 60″ x 30″ tub. Even those few inches regained by switching out a standard tub for a shower can go a long way toward making a claustrophobic bathroom feel roomier.

In addition, the range of shower pan sizes and shapes allows great flexibility in placement. Awkward corners and walls that are too short to fit the average length tub can often accommodate a shower pan, be it prefabricated or custom-made. Because of this variety, homeowners are more likely to achieve an optimal layout that makes the most of limited space in a bathroom.


Last but certainly not least, the accessibility a shower affords makes it an attractive remodeling choice. The low, three- to four-inch threshold of a shower pan as well as helpful features like shower rails make bathing simpler for homeowners who are aging in place or who have to contend with limited mobility. Plus, if down the line a shower seat or bench becomes necessary, the relatively flat surface of a shower pan is more conducive to sitting than the curved bottom of a tub.

Photo: homedepot.com

So, You Want to… Install a Shower Pan

Size, Space, and Style

Are you wondering how to install a shower pan where there was none before? Prefab options certainly simplify the process. These models, available online as well as at your local big-box hardware store, range from 27 to 66 inches in width, so you’re almost sure to find one that fits the configuration of your bathroom. Should that turn out not to be the case, you can get just what you need with a custom shower pan made from concrete, stone, or tile. When selecting an appropriate pan, whether prefab or custom, it’s critical to consider the following:

Decide on a door first.

A shower pan can’t necessarily take up all the available space in a bathroom corner. When determining the right pan size, you also need to account for the space required by whatever door you select for the shower enclosure. Consider the variety of doors and stalls available: sliding versus swinging, corner door versus side door, or perhaps no door at all! In Europe and Mexico, it’s popular to skip the door altogether, either hanging a curtain to contain splashes or leaving the shower area open and placing a drainage hole in the bathroom floor to draw away overspray. Each style has its pros and cons. A swinging door requires enough clearance outside the shower for it to open without hitting a toilet or other fixture—and this may mean that there will be a little less square footage available for the shower stall and pan. A sliding door, on the other hand, requires enough space to retract, so one side of the pan needs to be double the width of the door. The third option, eliminating the door completely, offers the most flexibility in cramped spaces, but at the price of having to deal with overspray every time you take a shower. Either way, you have to nail down the door style before you can be certain how much floor space is available for the shower pan.


Allow enough room for you.

It may seem obvious, but beyond the constraints of the room, a big factor in determining shower pan size is you. How wide are you? How much room do you need to comfortably lather up and rinse off? If you’re a former linebacker, you’ll need a much larger shower space than, say, a 5-foot-3 gymnast. To get an idea of how much room you need, try out your best “YCMA” moves in the potential space.

Choose between a ready-made shower pan and a custom creation.

As mentioned, your space may dictate whether you can buy something prefabricated or whether you’ll need a custom shower base. For example, sometimes the perimeter of the bathroom juts in so that a standard shower pan won’t fit, or you just can’t find a suitable shower pan in the length you need. But this choice isn’t only about necessity; aesthetics also factor in. Most store-bought shower pans feature acrylic, fiberglass, or porcelain finishes in a neutral hue, while custom creations in such materials as concrete and tile encourage a little more creativity in execution and appearance. A custom shower—a renovation that can boost a home’s resale value—can certainly be left to the pros, but it could also be a DIY job for a homeowner who is comfortable working with concrete or mortar and tile.

Installing a shower?Leave it to the pros. Compare multiple quotes from licensed contractors in your local area today. Compare quotes+

Photo: homedepot.com

What to Expect During Installation

Even though custom shower pans vary widely from one bathroom to the next, they share many of the same installation considerations that apply to store-bought models. In general, follow the manufacturer’s instructions for a prefab pan to a T, keeping in mind these key steps.

Take extra precaution to waterproof.

Lay out a plastic shower curtain liner over the subfloor before you place your shower pan. Should you make any mistakes during the installation process, this extra (and cheap!) layer of waterproofing between your subfloor and your shower pan will act as a saving grace. Apply a ring of caulk around the drain and then, once the shower pan is in place, seal along the perimeter where the pan meets the wall with a bead of caulk.

Ensure that the floor (and the shower pan) are both level.

A slight slope built in to an acrylic or fiberglass shower pan allows water to drain properly, and the pan has to be completely level for it to do the job correctly. Before installation, use a four-foot level to check the bathroom floor; if it’s not level, you’ll have to compensate by shimming the shower pan until it’s level and then affixing it to the nearest wall studs using the fasteners included with the shower pan kit.


Pay attention to the location of the drain pipe.

DIY-minded remodelers should select a shower pan that has a drain hole that will align with the drainpipe. This will save you a lot of effort (and headaches) when connecting the plumbing. Forcing or jerking the pipe into place is a big no-no, since it can lead to slow leaks over time and joint failure down the line. Fortunately, most kits specify left, right, or center drain. When you get started with the installation, the drainpipe should extend roughly 1/4 inch above your subfloor in order for it to attach properly.

Take it for a test run.

Once you’ve successfully fit your pan, attached the drainpipe, secured the flange, and made all connections according to the manufacturer’s instructions, run the shower once to inspect for leaks. It’s also wise to plug the drain for a minute while the water is running, then stop the water and see if the water level holds to make sure the pan’s not leaking anywhere. If everything looks good, your shower should be set.

Photo: homedepot.com

Signs You Should Replace an Existing Shower Pan

Assuming proper installation, the average commercial shower pan should last a decade or more and often comes with a manufacturer’s warranty to guarantee the product itself. As it nears the end of its lifespan, though, a shower pan can break down. To prevent a compromised pan from letting water permeate and damage the subfloor of your bathroom, keep your eyes open to signs of old age:

Installing a shower?Leave it to the pros. Compare multiple quotes from licensed contractors in your local area today. Compare quotes+

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