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Shower Base Sizes and Thresholds Compared: AcrylX Barrier-Free, SMC Linear-Drain, Molded-Seat and Cultured Marble Bases

Updated September 2026

Ella's Bubbles shower base sizes and thresholds fall into four families, and the differences that matter most are the threshold height, the drain style, whether a tile flange is built in, and weight. AcrylX barrier-free bases have a beveled entry between 3/4 inch and 1 1/8 inch depending on size. SMC bases have a 1 inch or 1 1/8 inch threshold with an integrated linear drain. The 36 by 60 molded-seat base has a 5 inch step-in, and the cultured marble bases are heavy solid slabs with a trench or standard drain. Here are the printed figures side by side, with links to the installation guide for each family.

AcrylX Barrier-Free (roll-In) Bases

White acrylic Ella roll-in shower base with a left-side drain and anti-slip textured floor
An AcrylX roll-in base: beveled entry, textured floor and a 2 inch drain.

These are pre-sloped, self-supporting and pre-leveled, so they install on the existing subfloor with no recess and no mud set. The floor is textured and slip resistant, the beveled entry has a built-in stainless steel bar structure in the threshold, and each ships with a 2 inch chrome strainer brass drain with friction seal. The spec sheets print a lifetime warranty on these bases. Sizes and printed figures:

  • 60 by 36, left or right drain: 37 wide by 60 long by 4 1/2 inches high, 1 inch threshold, 190 pounds crated.
  • 60 by 36, center drain: 7/8 inch threshold, 190 pounds crated.
  • 60 by 30, center drain: 31 wide, 3/4 inch threshold, 185 pounds crated.
  • 62 by 32 and 62 by 38, center drain: 3/4 inch threshold, 195 pounds crated. The sheets list these as meeting ANSI Z124.2, IPC, UPC, ADA and TAS, and the 62 by 32 is presented on its product page as the caregiver base.
  • 60 by 48, center drain: 1 1/8 inch threshold, 210 pounds crated.
  • 60 by 61, center drain: 1 1/8 inch threshold, 255 pounds crated; the product pages also list a 61 by 61 double-entry version at 1 1/4 inches.
  • 54 by 30 and 54 by 36, left or right drain: 1 inch threshold, 185 and 188 pounds crated, 4 1/4 inches high.
  • 50 by 50, center drain: 1 inch threshold, 120 pounds crated.

Package options on every barrier-free sheet include 24, 36 and 42 inch grab bars in standard or chrome linear styles, a padded 32 by 21 inch seat with fold-down legs, a slide bar with hand shower, a weighted anti-bacterial nylon shower curtain, a stainless curtain rod, and the collapsible rubber dam with horizontal or vertical end caps for barrier-free models. Accessories ship loose for field installation. The setting sequence is in installing shower bases, the flexible dam and shower walls.

The Collapsible Dam on Video

The video shows why the barrier-free thresholds can be so low: a flexible rubber dam sits at the entry, compresses under a wheelchair or shower chair caster, and springs back to hold water in the stall. It runs through the installation: measure, clean the surface with alcohol, lay a tape guide line, cut the dam, fit the end caps, peel the backing as you seat the dam snug against the wall and floor, then tape both sides and run a thin silicone bead along the lower edges and the end caps.

SMC Linear-Drain Bases

White Ella SMC accessible shower pan with a stainless steel linear drain, front view
An SMC base with its integrated linear drain along the front edge.

SMC (sheet molding compound) bases are a fiberglass composite pressed at high pressure and temperature, with a stone-texture slip-resistant surface, an integrated linear drain and a high load-bearing rating, installed floor-mounted with no recess.

  • SMC 1 inch low profile reversible base: 32 by 60 and 36 by 60 nominal (31 1/2 by 59 and 35 3/8 by 59 actual), 1 inch threshold for ADA compliance, linear drain placed left or right. The package includes the drain, the drain cover and a tile flange.
  • SMC ADA barrier-free base: 33 1/2 by 61 1/2 and 37 1/2 by 61 1/2 inches, 1 1/8 inch threshold, linear drain on the front side, drain included.

Care for SMC bases is simple: a non-abrasive cleaner with warm water, no bleach or ammonia, periodic cleaning of the linear drain and drying the surface to limit hard water spots. Installation is in installing the SMC low-profile shower bases.

36 by 60 AcrylX Base with Molded Seat

This base is for people who want a built-in seat rather than a folding one. It measures 37 1/4 wide by 60 long, with a molded seat 17 1/2 wide by 31 long by 24 inches high in a left or right position, a center 2 inch drain, a tile flange, a molded foot ledge, a textured non-slip floor and a 5 inch low step-in threshold. It ships pre-assembled and is aimed at new construction. The drain cover is not included. It pairs with the walls described in installing the 60 x 33 three-piece shower with molded seat.

Cultured Marble Bases

The video presents the cultured marble bases in three sizes as sturdy, heavy, solid molded bases with a glossy gel coat finish and an ADA compliant slip-resistant textured floor, giving the look of natural marble or granite. Because they are heavy, at least two people are needed to install one. The printed sheets give: 36 by 60 standard drain base, 35 1/4 by 59 actual, 88 pounds, white gloss, one-piece, left or right drain located 15 1/4 inches from the side and 15 1/4 inches from the back wall; 36 by 60 trench-drain base, 88 pounds, and 30 by 60 trench-drain base, 82 pounds, each with a removable brushed stainless trench drain cover, left or right hand, pre-leveled and pre-pitched. The cultured marble brochure lists 30 by 60, 32 by 60 and 36 by 60 reversible bases finished on all four sides. None of the cultured marble bases has a molded tile flange; three fiberglass tile flanges are included and are installed with 100 percent silicone and screws after the base is positioned. The bases come in standard sizes and are not custom-fitted.

Choosing Between Them

For a wheelchair or a caregiver-assisted shower, the lowest thresholds are the AcrylX 60 by 30, 62 by 32 and 62 by 38 at 3/4 inch, with the dam holding the water in. For a remodel where the finished wall will be tiled, the SMC reversible base and the molded-seat base bring their own tile flange. For the look of stone, the cultured marble bases trade weight for a solid gel coat surface. The full kit and wall pairings are in Ella shower kits and bases, and if you are still deciding between a shower and a walk-in tub, walk-in tub or low-threshold shower? compares them for mobility, space and caregivers.

Common Questions

Which base has the lowest threshold?
The lowest are the AcrylX barrier-free 60 by 30, 62 by 32 and 62 by 38 bases at 3/4 inch. Next comes the 60 by 36 center-drain AcrylX at 7/8 inch, followed by the 1 inch sizes, which include the SMC reversible bases and the AcrylX 60 by 36 left or right drain, 54 by 30, 54 by 36 and 50 by 50. On the barrier-free bases the collapsible rubber dam is what holds the water in at those heights.
What sizes do the AcrylX barrier-free bases come in?
The AcrylX barrier-free line is printed in 50 by 50, 54 by 30, 54 by 36, 60 by 30, 60 by 36, 60 by 48, 60 by 61, 61 by 61, 62 by 32 and 62 by 38. The 60 by 36 is offered with a center drain or a left or right drain, the 54 by 30 and 54 by 36 are left or right drain, and the remaining sizes are center drain. The 62 by 32 is presented on its product page as the caregiver base.
What is the SMC base threshold?
The SMC low profile reversible base, in 32 by 60 and 36 by 60 nominal sizes, has a 1 inch threshold for ADA compliance. The SMC ADA barrier-free base, in 33 1/2 by 61 1/2 and 37 1/2 by 61 1/2 inches, has a 1 1/8 inch threshold. Both are floor-mounted with no recess and carry an integrated linear drain.
Which bases include a flange?
The SMC reversible base package includes a tile flange along with the drain and drain cover, and the 36 by 60 molded-seat base has a tile flange built in. Cultured marble bases have no molded flange, but three fiberglass tile flanges are included and are installed with 100 percent silicone and screws after the base is positioned. The AcrylX barrier-free sheets show the flange on their drawings, so if it matters for your wall finish, ask the team to confirm it for your specific size.
How much do the bases weigh?
AcrylX barrier-free bases run from 120 pounds crated for the 50 by 50 up to 255 pounds crated for the 60 by 61, and the product pages list approximate uncrated weights from about 60 pounds for the smaller sizes to about 135 pounds for the 60 by 61 and 61 by 61. The cultured marble bases are 82 to 88 pounds and, because they are solid slabs, need at least two people to install. Plan the delivery path and the lift with those figures in mind.
Do the bases need a recess in the floor?
No. The AcrylX barrier-free bases are self-supporting and pre-leveled, the SMC bases are floor-mounted, and the cultured marble bases are pre-leveled and pre-pitched, so all three families install directly on the existing subfloor. There is no recess to cut and no mud set to build.
Can I get a cultured marble base in a custom size or in black?
No. The cultured marble bases come in the standard sizes listed above, in white gloss, and are not custom-fitted. If you need a size outside the standard range, ask your Ella dealer or the team at (800) 480-6850 about the current custom-size options in the acrylic line.
Can I drill the threshold for a door track or the dam?
No. Drilling into a shower base threshold voids the base warranty, so plan any door track or mounting with your installer before the base is set. The collapsible dam does not need screws; it attaches with adhesive tape and a thin bead of silicone along the lower edges and end caps, as shown in the video above.
Is the dam included?
Yes. The collapsible rubber dam comes standard with the roll-in barrier-free bases, with horizontal or vertical end caps to suit the entry. Like the other package accessories, it ships loose for field installation, and the setting sequence is covered in the shower base and dam installation article linked above.

For anything model-specific, including the exact spec sheet for the base or shower on your order, open a ticket at ellasbubbles.com/support or call (800) 480-6850 and the team will be glad to help.

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