What Is a Collapsible Rubber Dam on a Roll-In Shower?

A collapsible rubber dam, also called a water retainer, flexible shower dam or collapsible threshold, is the self-adhesive rubber strip that comes standard with Ella roll-in barrier-free shower bases. It sits across the open entry of the stall to keep water inside while a wheelchair or walker rolls right over it, flattening under the wheels and springing back once they pass. It gives a barrier-free shower the water control of a curb without the curb.

How It Works

The dam attaches with strong, water-resistant self-adhesive tape, so no drilling is involved, and it is installed in 12 steps. The one non-negotiable rule is that the mounting surface must first be cleaned with isopropyl rubbing alcohol, or the adhesive will not bond. Your installer peels back about 24 inches of the orange backing, starts about 1/2 inch from the square corner, presses on the first 4 inches, then stretches and aligns the strip toward the center of the shower and on to the opposite wall before removing the rest of the backing. The excess is cut about 1/2 inch from the wall, the end caps are dry-fitted and siliconed at their male ends and on the wall side, a thin bead of silicone runs along both lower edges, and masking tape holds the caps until everything cures. On tile floors the grout line beneath the retainer must be caulked so water cannot travel under it. The step-by-step guide is in shower base and dam installation.

Which Ella Models Have It

The collapsible dam is standard with the roll-in, wheelchair-accessible shower bases in Ella's accessible shower line. Low-threshold acrylic bases and cultured marble bases have a molded threshold instead. Thresholds, weights and drain styles for each base are compared in shower base sizes and thresholds compared, and the SMC linear-drain bases have their own guide in SMC shower base installation.

What to Know as an Owner

Protect the base warranty first: never drill into the shower base threshold, since drilling the threshold voids the warranty, and plan any door track or dam mounting with your installer so nothing penetrates it. Let the silicone cure fully before the first shower. Afterward, rinse the dam with the rest of the floor, use only the non-abrasive cleaners recommended for the base and check periodically that the ends and caps are still sealed to the wall. If the dam ever lifts, the cause is almost always a surface that was not alcohol-cleaned or grout that was left uncaulked. For a ticket, have the base model, the date of installation, photos of the dam at both ends and a note about the floor material ready. Warranty rules for the bases themselves are in shower base warranty coverage.

When You Do Not Need the Dam

If a track with sliding glass doors is installed on your barrier-free base, the collapsible rubber dam is not necessary. The door track is a permanent barrier along the front of the base, and with the doors closed it contains the spray from the shower head. Adding the dam in front of or behind the track serves no purpose, so the flexible strip can be left out of the installation. The same answer applies whether the doors go on at the original installation or later, when a household no longer needs the open roll-in entry. If a dam is already in place, remove the old strip before the track goes on so the track seats flat on the base.

You still want the dam in two situations: when the shower opening is left completely open for roll-in access, and when a curtain is used instead of a door, since a curtain does not seal against the base. In these cases the dam is the only thing keeping water on the base. Install it as described above and replace it if it becomes torn or stops springing back.

Both options keep water where it belongs, so the choice comes down to the entry. Sliding doors give a finished look and a firm barrier but leave a track on the floor that a wheelchair has to cross. The dam keeps the entry completely flat at the cost of a soft strip that must be stepped or rolled over. Which base you have also matters, so review shower base sizes and thresholds compared before deciding.

The dam is offered in several lengths so it can be matched to the width of the opening, and the end caps that finish each end of the strip are ordered as a separate item. If you need a dam, a different length, or a set of caps for an existing base, contact your Ella dealer or call (800) 480-6850 with the base model and the width of the opening so the correct length and caps are supplied together.

Related Guides

• What is a roll-in shower for wheelchair users?
• What Is the Difference Between a Roll-In Shower and a Walk-In Shower?
• What is a roll-in shower and how does it work?
• What is the difference between a roll-in shower and a walk-in shower?
• What is a roll-in shower and who is it designed for?
• What Is a Shower Dam and When Do You Need One?

Common Questions

Have a question about your base or dam? Open a ticket at ellasbubbles.com/support or call (800) 480-6850 and the team will help your installer.