How Deep Is a Shower Pan and Does Depth Matter?

On an Ella acrylic shower base, depth means the height of the step-in edge, not how much water the pan can hold. That height runs from flush with the floor on a barrier-free base to a low threshold that the published examples put at 2, 3 or 4 inches, and drainage comes from the slope molded into the floor rather than from depth. The standard footprints are compared in What are standard shower pan sizes and how deep are they?; this page looks only at depth and at when it does and does not matter.

What Depth Means on a Shower Pan

A bathtub is deep because it holds water. A shower pan is not meant to hold anything; its job is to catch water and move it to the drain, and the only vertical dimension that changes how you use it is the threshold you step or roll over. When people ask how deep a shower pan is, that threshold is almost always what they need to know. Ella makes its bases in low-threshold and barrier-free versions, and the height varies by style.

What the differences mean: the taller the threshold, the more of a step it is for someone with limited mobility, and the lower the threshold, the easier the entry and the more the design relies on the floor slope, the drain and, at zero threshold, a dam to keep water where it belongs. A 3/4 inch step and a flush floor can look alike in a product photo, which is why the threshold figure on the spec sheet, not the image, should drive the decision.

Does Depth Matter for Drainage?

No. Every Ella base has a textured, slip-resistant floor with the slope and drainage channels molded in, so water is carried to the drain by the shape of the floor, and a 2 inch threshold drains the same way a 4 inch one does. What does matter is where the drain sits. On the three standard sizes the drain is in a set position for that size, left or right. On a custom base the drain can be placed left, right, center or in a custom position, with the rule that it sits at least 9 inches from each wall, and the threshold goes on the longer side. Match the drain location to your plumbing before you order, because the base arrives as the finished floor.

That last point is why you cannot make a pan deeper or change its pitch after the fact. The acrylic surface is not a substrate for tile; thinset does not bond to it, and tiling over the pan would bury the molded slope and threshold and could trap water with no path to the drain. Can You Tile Over an Ella Acrylic Shower Base? explains that the correct way to make the base feel solid is support from underneath, not a layer on top. If the threshold or drain position is wrong for the room, choose a different base rather than covering one.

Does Depth Matter for Accessibility?

Here it matters a great deal. A short step-in threshold is still a step. ADA standards generally limit the threshold in a roll-in shower compartment to 1/2 inch, so a low-threshold pan is not labeled ADA, and the 3/4 inch Accessible Caregiver threshold normally does not meet that figure either. For a wheelchair roll-in, the sure route is a ready-made barrier-free base, which sits flush with the surrounding floor and pairs with the collapsible rubber dam that keeps water in while a wheelchair rolls over it. The custom program lists a barrier-free style in its selector, but true roll-in thresholds need different molds, so if you need roll-in access at a non-standard size, ask your Ella dealer or the team at (800) 480-6850 whether it can be built before planning around it.

How to Choose a Threshold Height

The published sources do not name a single comfortable depth, and there is no reason they should, because the right threshold depends on who uses the shower.

• Everyone in the household steps in unaided. A low-threshold pan is the simplest choice. If a standard 30, 32 or 36 by 60 inch footprint fits the alcove, it arrives ready to set with the drain in its set position.
• Someone uses a walker or is helped by a caregiver. Look at the lowest step available, and confirm the exact threshold figure when you order rather than judging from a photo, since the same footprint can be built with more than one step height.
• Someone uses a wheelchair. Plan on a barrier-free base with the dam, and treat the 1/2 inch ADA figure as the target.
• The room is an odd size. Custom bases run from 30 by 30 up to 44 by 80 inches in rectangles only, corner bases up to 42 by 60 inches, all as low step-in pans with the threshold on the longer side. Sizes such as 46 by 46, 50 by 30 and 36 by 44 have all been handled. The options are laid out in Custom-Size Shower Bases. Availability of the custom program has changed over time, so confirm it is open for your size first.

Whichever height you land on, ask for the spec sheet for that exact base, check the threshold and drain figures on it, and hand it to your installer so the plumbing rough-in matches the pan that arrives.

Related Guides

• Shower Base Sizes and Thresholds Compared: AcrylX Barrier-Free, SMC Linear-Drain, Molded-Seat and Cultured Marble Bases
• Is a 3/4-Inch Shower Base Threshold ADA Compliant for a Commercial Building?
• What Is the Step-In Threshold on a Walk-In Tub?

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