Livable Later

Practical home changes for staying safely at home

Bathroom safety

Walk-in tubs and curbless showers, and how to choose

A walk-in tub fills after you sit down. A curbless shower rolls in. The right one depends on the transfer, the floor, and the drain.

Livable Later editorial team · Updated November 1, 2026 · About 9 minutes

People shop for these two products as if they were styles of the same fixture. They are not. A walk-in tub is a bathtub with a door. You step over a low sill, sit, close and lock the door, and wait while the tub fills. You wait again while it drains before the door can open. A curbless shower has no dam. The floor runs, or nearly runs, straight into the shower, and the water leaves through a sloped pan and a drain while you are still in the room. One is for soaking in place. The other is for getting in and out without a step.

Neither product is a medical treatment. Hot water, long soaks, and the effort of bathing can matter for heart conditions, blood pressure, and skin. Ask a clinician whether a soak is appropriate before you demolish a bathroom to install a tub whose main feature is a deep soak. An occupational therapist can say which transfer the person can actually do. This page is about the building.

What "walk-in" does not mean

The phrase suggests an easy entrance. The door still has a sill, often a few inches high, because the door has to seal against a full tub of water. Someone who cannot lift a foot those few inches, or who uses a wheelchair and needs to roll, has not been given a roll-in shower. They have been given a different step.

Once the door is shut and the tub is filling, the person is committed. Fill times of several minutes are normal, and drain times are too. If the water is too hot, or the person feels faint, the door does not open until the water is down. Ask the seller what happens when the power fails. A tub that depends on an electric pump to drain, with no mechanical backup, can hold someone in cooling water during an outage. That question belongs in the contract, not in a brochure photograph.

The door swing has to be drawn on the real floor plan. An inward door needs room inside the tub. An outward door needs room in front of it, which in a small bathroom is often the toilet. Measure with the door open and a helper standing where a helper would stand. Then read the grab-bar locations for a tub, because a walk-in tub is still a tub. The bars in section 607 of the 2010 ADA Standards are the drawing to start from, adjusted for this seat and this door.

Most walk-in tubs need a dedicated electrical circuit for the pump, the heater, or both, and a GFCI-protected connection installed by a licensed electrician. The old tub's drain location may not match the new one. Moving the drain is a plumbing job in the ceiling of the room below, or in a slab. Get that looked at before you believe a one-day installation claim.

Who a walk-in tub is actually for

It fits a person who can step over the sill, sit down with control, wait, and stand up again from a wet seat, and who wants to soak rather than take a short shower. It is a poor fit for someone who cannot be left behind a latched door, including many people with significant memory loss who may try to stand and open the door while it is full. It is a poor fit if bathing has to be fast because the person gets cold or tired. It is the wrong tool if the goal is a wheelchair transfer. Say that out loud in the showroom.

Weight rating, seat height, and the handheld sprayer are model-specific. Do not accept "standard." Sit in the floor model if you can, with the shoes you wear at home, and have someone time a pretend entry. The seat and control guide covers reach and anti-scald valves, which apply here too. A fast-fill heater does not replace a thermostatic mixing valve.

Cleaning is ordinary but fiddly. The door gasket is a wear item. A leaking gasket is a flood, not a drip, because the water is stored, not flowing to a drain. Ask who replaces the seal, what it costs as a part, and whether the tub has a tested overflow. Write the answers on the quote.

How a curbless shower stays dry

A curbless, or zero-threshold, shower works only if the entire wet area is a waterproof pan that slopes to a drain. The pretty tile is the finish. The safety is the membrane under it. Cement board alone is not waterproof. Water that passes the grout has to hit a bonded sheet membrane or a liquid-applied membrane, reach the drain flange, and leave the house. If it hits wood joists instead, the failure shows up months later as a soft floor or a stain downstairs.

Many adoptions of the International Plumbing Code require a shower floor to slope toward the drain, commonly at least one-quarter inch per foot. Confirm the number in the code your city has adopted. A floor that is "almost flat" ponds. A floor that is too steep is a slip. The slope is a designed plane, not a feeling the tile setter has.

Two drain layouts dominate. A center drain means the floor slopes from every side, which is simple in a small square shower and awkward when the shower is the whole end of the room. A linear drain near the entry can let most of the floor slope in one direction. Either can work. The linear drain's grate has to be one a wheelchair caster or a cane tip will not drop into. The 2010 ADA Standards, section 302.3, limit openings in the direction of travel in walking surfaces. Use that as the bench test for the grate you are shown.

The threshold rule of thumb from ADA section 404 and the shower chapters is one-half inch, and roll-in showers are built to be flush. "Curbless" in a sales sheet sometimes means a two-inch curb that was shortened. Ask for the finished height from the bathroom floor to the shower floor. If it is more than a quarter inch, it is a level change, and the floor guide explains why quarter-inch vertical edges are the usual maximum before a bevel is required.

The structural problem nobody puts in the ad

The shower floor wants to be lower than the bathroom floor so the slope has somewhere to go, or the bathroom floor has to be built up. In a wood-framed house, lowering the pan means cutting joists or sistering a recessed pan between them. That is structural work. A joist that is simply notched until the pan fits can weaken the floor. In a concrete slab, recessing means cutting concrete and reworking the trap. Both are legitimate. Both are why a curbless shower is a remodel, not an accessory.

The other approach builds the bathroom floor up and feathers it back to the hall. A one-inch rise at 1:20, the steepest slope the ADA still treats as a walking surface rather than a ramp, needs 20 inches of run. Steeper, and the bathroom door has become a ramp. The ramp guide is the math.

Waterproofing has to turn up the walls, typically into a full-height wet zone behind the tile, and it has to marry to the drain with a clamping ring or a bonded flange made for that membrane. Niches, benches, and windows are where installers get casual. A bench that is not sloped to drain and not wrapped in membrane is a bucket. Specify the membrane system by name in the contract and ask for a flood test, plugged drain, water left standing, before the tile goes on. Tile does not fix a leak. Tile hides it.

Turning space, a seat, and the helper

If a wheelchair might be used in this room, even part of the time, plan a roll-in shower rather than a transfer shower. Under the 2010 Standards a transfer shower is 36 by 36 inches with a seat, which requires a person to move from chair to seat. A standard roll-in is at least 30 by 60 inches. A 60-inch turning circle, section 304.3, is the planning number for turning inside the room, and it often will not fit inside the shower itself. Be honest about which of those you are buying. A beautiful 36-inch curbless stall is not a roll-in.

The seat, the handheld spray, and the valve location decide whether the shower is usable from a seated position. Those dimensions are in the seat and control guide. Put them in the drawing before the tile is chosen. Grab bars go into blocking, and blocking goes in before the membrane is closed. The sequence is blocking, membrane, flood test, tile, then bars into the blocking through a properly sealed penetration. Bars drilled as an afterthought through a finished pan are how membranes fail.

A helper needs to stand beside the person, not in the water's slope. A curtain that pulls fully back beats a glass panel that blocks a second person. If you use glass, it has to be safety glazing, and it is not a grab bar.

A decision you can write down

Choose a walk-in tub only if most of these are true

  • The person can step over the actual sill height, measured on the model, not estimated from a photo.
  • Sitting through a fill and a drain is acceptable, and a clinician has no objection to a hot soak.
  • The person can be relied on not to force the door while the tub is full.
  • The bathroom has a legal electrical circuit and a drain location the plumber has seen.
  • The quote lists the gasket as a replaceable part and states what happens in a power failure.

Choose a curbless shower if most of these are true

  • Getting in and out matters more than soaking.
  • A carpenter has a plan for the slope that does not depend on notching a joist at random.
  • The contract names the waterproofing system and includes a flood test before tile.
  • The finished threshold is flush or within a quarter inch, and the grate will not trap a cane or a caster.
  • Seat, valve, handheld, and grab-bar blocking are drawn, not left for "the tile guy."

You can also do neither yet. A stable shower chair, a handheld sprayer on the existing tub, a real grab bar in blocking, and a non-slip floor solve the transfer for some people at a much smaller scope. The National Institute on Aging's home safety checklist starts with those simpler steps: a shower stool, a handheld head, and non-slip strips. Use the large remodel when the simple tools no longer match the person's transfer, not because a showroom made the old tub look like a hazard by itself.

Costs for either project spread widely because the money is in plumbing, electrical, structure, and tile, not in the fixture logo. The cost guide explains how to read a bid so a low number is not missing the membrane or the joist work. Compare at least two itemized quotes. A single allowance that says "shower, by owner selection" is not a price.

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