Schluter Shower Pan Sizes: A Complete Guide for Homeowners

The number one reason a tile shower leaks is a failed pan, and the beauty of the Schluter system is that it moves waterproofing to the surface where the tile sits. Getting the Schluter shower pan sizes right is the first decision in a Kerdi build, because the tray sets the slope, the drain location, and how much cutting your tile setter faces. Choose from the standard Schluter shower pan sizes correctly and you get a factory-sloped, foam tray that installs in an afternoon and never needs a mud float. This guide lays out every size, drain option, and cutting rule so you order the right pan the first time.

Part of our Bathroom Remodeling & Flooring guide — explore the full guide →

How the Schluter Kerdi System Works

Traditional shower pans rely on a rubber liner buried under a mortar bed, and water sits in that bed until it evaporates. Schluter flips the concept. The Kerdi-Shower-ST and Kerdi-Shower-SR trays are pre-sloped expanded polystyrene foam. You bond the tray to the subfloor with thinset, cover it and the walls with the orange Kerdi waterproofing membrane, and tile directly on top. The waterproofing lives right under the tile, so water never penetrates the assembly.

Because the slope is molded into the foam at the factory, you skip the trickiest part of shower building: hand-floating a consistent quarter-inch-per-foot slope to the drain. That single feature is why so many DIYers and pros choose the system.

Standard Kerdi Shower Tray Sizes

Schluter offers a wide range of rectangular and square trays. The most common center-drain sizes are:

• 32 x 60 in — the standard American tub-replacement footprint
• 48 x 48 in — a roomy square shower
• 36 x 60 in — a slightly deeper alcove
• 32 x 32, 36 x 36, 38 x 38 in — corner and square showers
• 48 x 72 and 60 x 72 in — large walk-in showers

The 32-by-60 tray is by far the most popular because it drops straight into the space left by a removed bathtub. Trays come in both center-drain and off-center configurations, which brings us to drain placement.

Center Drain vs Off-Center Drain

The Kerdi-Shower-ST trays place the drain in the center of the tray, while the Kerdi-Shower-SR trays position it off-center, typically shifted toward one end. Off-center trays matter when your existing drain rough-in is not centered in the space, which is common in bathtub conversions where the tub drain sat near one end.

Before you order, locate your drain rough-in and measure its distance from each wall. If it lands near the center, an ST tray works. If it is offset, an SR tray or a linear-drain tray saves you from re-plumbing. Schluter also makes trays for the Kerdi-Line linear drain, which sits along one edge and allows a single-plane slope, popular in modern curbless showers.

Cutting Trays to a Custom Size

Here is the flexibility most homeowners miss: Schluter foam trays can be cut smaller. If your shower is 34 by 58 inches, you buy the next size up and trim the tray down with a utility knife or a fine-tooth saw. The rule is simple. You cut from the perimeter, keeping the drain in its original relationship to the slope, and you never cut so far that you flatten the slope near the drain.

Schluter’s documentation specifies minimum dimensions you must keep on each side of the drain to preserve proper drainage. As a practical guide, plan to keep at least a few inches of sloped foam between the drain and any cut edge. Trimming equally from opposite sides keeps the drain centered; trimming from one side shifts it, which can help match an off-center rough-in.

Matching the Tray to Your Drain and Rough-In

Schluter drains come in two families. The Kerdi-Drain is a low-profile bonding-flange drain that connects to a 2-inch PVC or ABS pipe and integrates with the Kerdi membrane. Make sure the drain kit you buy matches your pipe material and diameter. Standard residential showers use a 2-inch drain line, and the Kerdi-Drain adapter is sold for both PVC and ABS.

• Confirm pipe size: almost always 2 in for showers
• Confirm pipe material: PVC or ABS, buy the matching flange
• Check rough-in height: the drain body must sit at the right depth under the tray

Curb, Bench, and Wall Components

The tray is one piece of a full kit. Schluter sells matching foam curbs (the Kerdi-Shower-CU) in standard lengths of 38, 48, and 60 inches that you cut to fit and bond in place, plus prefab foam benches (Kerdi-Shower-SB) and niches (Kerdi-Board-SN) in sizes like 12 by 12 and 12 by 20 inches. Buying these prefabricated keeps the whole assembly consistent and waterproof, and every component bonds together with the same Kerdi-Fix sealant and Kerdi-Band at the seams.

For a curbless or ADA-friendly build, skip the curb and use a linear-drain tray that slopes to one edge, allowing a flush transition into the bathroom floor. That configuration needs a recessed subfloor, so plan it before framing.

How to Choose the Right Size for Your Space

Start by measuring the finished interior dimensions you want, wall to wall, then account for wall thickness. The tray sits inside the framed opening, so if your rough opening is 60 inches wide and you are using a half-inch backer plus tile, the tray needs to be a couple inches narrower than the rough framing. Order the tray that either matches your interior dimension or is the next size up so you can trim it down.

When in doubt, go up a size and cut, since you can always remove foam but never add it. Verify your drain location against the tray’s drain position before ordering, and confirm the whole kit, tray, drain, curb, and membrane, is compatible. Get those numbers right and the Schluter system delivers a bulletproof, factory-sloped shower base that tiles cleanly and stays dry for the life of the bathroom.

Kerdi vs Traditional Mud Pans

It is worth understanding why the Kerdi system has won over so many tile setters compared with the old mortar-bed method. A traditional mud pan relies on a rubber or PVC liner buried under a sloped mortar bed, with weep holes at the drain to let trapped water escape. The problem is that the mortar bed stays wet, water sits in it for days, and if the weep holes clog or the liner is punctured, the assembly fails silently and leaks for months before anyone notices.

The Schluter approach moves waterproofing to the surface, directly under the tile, so water never soaks into the assembly at all. That single change eliminates the wet mortar bed, dramatically cuts drying time, and makes leaks far less likely. It also speeds installation: a mud pan takes skill and a day or more to float and cure, while a foam tray bonds down in an afternoon with no curing wait for the slope. For DIYers especially, the elimination of hand-floating a perfect slope is the deciding factor.

Waterproofing the Whole Assembly

The tray is only waterproof if it is tied into the rest of the shower correctly, and this is where installs fail. Every seam and transition must be sealed with Kerdi-Band, the waterproofing strip, and Kerdi-Fix sealant.

• Tray-to-wall corners: seal with Kerdi-Band bedded in thinset
• Drain-to-tray connection: the drain’s bonding flange integrates with the Kerdi membrane
• Curb: wrap the foam curb fully in membrane, including both faces and the top
• Pipe and valve penetrations: seal with Kerdi-Seal gaskets or Kerdi-Fix

Before tiling, many pros run a flood test by plugging the drain and filling the pan with an inch or two of water for 24 hours to confirm the waterproofing holds. It is an extra day, but it catches a problem while it is still an easy fix rather than after the tile is set.

Ordering the Complete Kit

Schluter sells the components separately and as complete kits, and for most homeowners the kit is the safer buy. A Kerdi-Shower-Kit bundles the correctly sized tray, the matching Kerdi-Drain, the curb, and the membrane in compatible sizes, which removes the guesswork of mixing and matching. Confirm three things before you check out: the tray dimensions match your framed opening with room to trim, the drain matches your pipe size and material, and the kit includes enough membrane to cover your specific wall area. Order a roll of extra Kerdi-Band for the seams, since running short mid-install stalls the whole job. With the right kit in hand, the system goes together predictably and leaves you with a shower base that will stay dry for decades.