What is the largest custom shower base Ella makes, and which threshold heights?

The largest custom shower base Ella's Bubbles builds is 44 inches wide by 80 inches long for a three-wall alcove, and a custom corner base tops out at 42 by 60 inches. The threshold comes three ways on a custom base, a 2 inch low threshold for a three-wall alcove, a 4 inch threshold for an alcove, or a 4 inch threshold on a corner base, while zero threshold roll-in pans sit flush with the floor for a barrier-free entry. The size limits on their own are covered in What Is the Largest Custom Shower Base Ella's Bubbles Can Make?, and this page puts the maximum, the corner limit, the threshold heights and the drain rules side by side so you can settle all of them before a floor is cut.

Size and Threshold Limits by Base Type

What the table means for your bathroom: the maximum is a hard stop. A request such as 53 by 76 inches or 89 by 48 inches is past the limits and cannot be produced, even though both are rectangles. If your contractor can bring the opening within 80 by 44 inches, a custom alcove base becomes possible again, but a corner base has its own lower ceiling of 42 by 60 inches. The threshold column matters as much as the size column. A custom base is a low step-in pan, and a genuine roll-in threshold needs a different mold, so a wheelchair user is usually better served by one of the ready-made barrier-free sizes than by a custom pan.

Choosing the Threshold Height

Ella uses the word threshold for the edge you step or roll across at the entry, and on a custom base you choose the style at the same time as the size.

• 2 inch low threshold. Offered on a three-wall alcove base only. It is the lowest step-over of the custom styles, for a bather who steps in and wants the smallest lip possible without moving to a roll-in pan.
• 4 inch threshold. Offered on an alcove base and on a corner base, and it is the only height available on a corner base. If your layout is a corner, plan around a 4 inch edge.
• About 3 inches on a typical custom base. Ella's materials describe a custom shower base as typically having a threshold of about 3 inches, and a 3 inch step-in threshold base is offered for those who prefer a slightly raised edge. Treat the 2 inch and 4 inch figures as the choices you make, and confirm the exact height with the team when the base is specified.
• Zero threshold. Zero threshold bases sit flush with the surrounding floor. Roll-in bases ship with a self-adhesive collapsible rubber dam that keeps water in while a wheelchair rolls over it.

On a custom base the threshold goes on the longer side, so the entry of a custom corner base faces out from the long edge of the rectangle. The threshold is molded into the acrylic together with the slope and the drain, which is why the base is ready to use once set and must not be tiled over. Wall panels are sized to the base, so the base dimensions are the first thing to settle, before any wall system or door.

Drain Placement, Off-Center Drains and Slab Floors

The drain can be placed left, right, center or in a custom position on a custom base, so an off-center drain is available. There is one hard limit: the drain cannot sit closer than 9 inches to the back or side wall. A drain only 7 inches from the threshold edge is not possible, even on a custom base, and no amount of custom sizing moves that line.

Before you request a size, measure from the center of your existing drain line to each wall. Those two figures tell the team whether the drain you already have can be matched or whether your plumber needs to move it. Your licensed plumber sets the 2 inch drain body to local code during installation, and the team confirms what drain hardware ships with the base.

A concrete slab with no access from below is the case where this matters most, because moving a drain means cutting the slab. For a slab, open a ticket at ellasbubbles.com/support with a simple drawing that shows the walls, the size you want, where the existing drain sits, and whether the space is a three-wall alcove or a corner. The team confirms whether a base can be made to match before your contractor cuts the floor. The same approach works for a tub-to-shower conversion, where a rectangle can very often be drawn into the space the old tub leaves behind and the existing drain often falls within the 9 inch rule.

Sizes That Have Been Built, and Requests That Cannot Be

Custom sizes are specified in quarter inch increments, and anything shorter than the standard 60 inch length is routine. Examples from past builds and requests make the limits concrete.

• Built: 46 by 46 inches, 50 by 30 inches, 36 by 44 inches, and a 58 by 30 inch base with a center drain.
• Within the limits: a 38 by 80 inch alcove base with a left drain.
• Cannot be produced: 53 by 76 inches, because it is wider than 44 inches, and 89 by 48 inches, because it is past both the 80 inch length and the 44 inch width.
• Not offered at any size: angled or curved edges, which rules out a neo-angle corner, an L-shaped footprint and a curved front. The corner question is covered in Does Ella Make a Neo-Angle Shower Pan With a Curb for Corners?.

The three standard sizes, 30 by 60, 32 by 60 and 36 by 60 inches, remain the simplest choice when one of them fits, because the drain sits in a set position for each size. What sizes do shower pans come in, from smallest to largest? lines up the standard and custom ranges, and Who makes custom shower pans for odd bathroom layouts? works through the layouts a rectangle can and cannot solve.

Measure the Finished Opening Before You Request a Size

Custom bases are built in white acrylic to the values on your order, and a custom order is final once it is submitted, so the measuring has to be right the first time.

1. Measure the finished opening, wall surface to wall surface, not the framing. Tile and backer board take up space a framing measurement does not show.
2. Note which side is open, and whether the space is a three-wall alcove or a corner. The team asks, because the threshold and the edges are placed differently for each.
3. Measure from the center of the existing drain to the back wall and to the nearest side wall, and check both against the 9 inch minimum.
4. Decide on the threshold style: 2 inch or 4 inch for an alcove, 4 inch for a corner, or a ready-made zero threshold pan for a roll-in entry.
5. Bring the length, width, open side, drain position and threshold choice to your Ella dealer or the team at (800) 480-6850, who confirm the base and the wall panels that go with it. Who Makes Custom Shower Pans and Bases for Accessible Showers? covers what else a complete shower needs.

Related Guides

• How Close to the Wall Can the Drain Be on a Custom Shower Base, and Can It Be Centered?
• Custom-Size Shower Bases: Size Ranges, Threshold Options, Drain Placement Rules, Construction, and How to Request One
• How long does a custom Ella shower pan take to build and ship?

Common Questions