Walk-in tub or walk-in shower?

What each one is

A walk-in tub is a manufactured fixture with a watertight door in its side. You open the door, step over a low sill, sit down, close the door, and then the water starts. You bathe seated and submerged. When you are done, the water has to leave before the door can open.

A walk-in shower is built in the room rather than delivered to it. In its best form it is curbless, meaning there is nothing at all to step over: the floor slopes to the drain and the shower floor and the bathroom floor are the same floor. In a house where the slab or the drain line will not allow that, it becomes a low threshold instead of a curb.

The first thing worth knowing is that they compete for the same space. A standard 60 inch alcove tub has exactly the footprint of a 60 by 30 inch roll-in shower. Whichever way you go, the room usually already has room for it.

The fill and the drain

This is the difference people are asking about when they ask about walk-in tubs, and it is a fair thing to ask. Because the door has to be closed and sealed before there is any water in the tub, and open only after there is none, you are sitting in the tub for both operations. You wait, dry and uncovered, while it fills. You wait again while it drains.

Some models fill faster, and some carry fast-drain pumps and heaters. Those are the two specifications to ask for by name, in writing, on the exact model being quoted: how long to fill at your house's water pressure, and how long to drain. A manufacturer who will not put those numbers on paper has told you something.

A shower has no equivalent problem. The water is warm from the first second and it stops when you stop it.

The door and its seal

Everything a walk-in tub does depends on a gasketed door sealing against a tub full of water, on every use, for as long as you own it. That seal is a wear item. It is the part that eventually needs attention, and a seal that fails while the tub is full puts the water on the bathroom floor rather than in the drain.

That is not an argument against the fixture. It is an argument for knowing which part is the wear part, asking who replaces it and what that costs before you buy, and keeping the seal face clean. St. George water runs 18 to 22 grains per gallon, which is hard enough that mineral deposit shows up on every wet surface in the house, seal faces included.

A curbless shower has no door at all when it is designed properly, and that is deliberate. In water this hard, glass etches and grout stains, and no amount of squeegeeing keeps up. We would rather build a layout that does not need glass than sell you a glass panel to scrub.

The threshold

A walk-in tub's threshold is much lower than the wall of a standard tub, which is the whole point of the fixture. It is not zero. There is still a sill at the door, and a person has to clear it while stepping into a wet enclosure and then lower themselves onto a seat.

A curbless shower's threshold is genuinely zero. A walker rolls in. A wheelchair rolls in. Someone helping can stand on the same floor as the person being helped, rather than reaching across a tub wall. If mobility is the reason for the project, that difference is the reason to look hard at the shower first.

Getting to zero on a St. George house is a construction question, not a fixture question. Most homes here are slab on grade, so the shower pan is either recessed into the concrete or the surrounding floor is built up over it. That is a different job from the same shower on a wood floor, and it gets priced as one.

The two, side by side

What it costs, stated honestly

The two are not comparable on a fixture price, and any comparison built that way is misleading. A walk-in tub is a manufactured product; most of what you pay for is the fixture, and the model number decides it. A shower conversion is mostly waterproofing, drain work, tile and labour; the room decides it.

So get both quoted for the same room, on the same written scope, and compare the whole number, including the floor, the valve, the drain and the tile. Ask each quote what is excluded. That comparison is real. A fixture price against a project price is not.

What does not change either way

A surprising amount of what makes a bathroom work is the same regardless of which fixture goes in, and it is the part quotes tend to leave out. It is worth checking both proposals for all of it.

The floor is the first item. Tile specified to a wet dynamic coefficient of friction of 0.50 or higher, which is the barefoot wet category created by the 2022 revision of ANSI A326.3. The 0.42 figure printed on many tile boxes belongs to a different category of floor, and it is the number a lot of showrooms will quote you.

Then the walls. While they are open, solid blocking goes in behind every place a bar might ever be wanted, including places nobody wants one today. It costs a few pieces of lumber during the job and it costs a wall afterwards. Bars themselves are rated to 250 pounds of force, and the ones that look like towel bars carry the same rating as the ones that look like grab bars.

And then the small hardware that decides how the room feels day to day: a hand-held shower on a slide bar, lever handles instead of knobs, rocker switches instead of toggles, a comfort-height toilet, and more light than a builder would have put in, aimed so it does not bounce off a wet floor into somebody's eyes.

Resale, and the tub question

The objection we hear most is that removing the only bathtub will hurt the house at resale. It is a fair concern and it has a real answer here.

Washington County is 22.4 percent aged 65 or over, and the CDC reports that 41.7 percent of US adults 65 and over have a disability, mobility being the most common at 26.9 percent. A no-step shower is a feature a large share of the local buyer pool is actively looking for, which is not true in most markets.

The practical rule we give people: if the house has a second bathroom, keep a tub in it and convert the one you use. If it is the only bathroom, that is a genuine trade and worth talking through before anyone starts demolition. A walk-in tub is one way to keep a tub in the house while solving the step, and that is a legitimate reason to choose one.

So which one

Written out like that, the shower wins most rooms and the tub wins some. That is the honest shape of it, and it is why we install both instead of picking a side and calling it a philosophy.

• If nothing has to be stepped over, the answer is a curbless shower. It is the only one of the two that gets to zero.
• If bathing seated and submerged is the point, and soaking is something you would miss, the tub is the fixture that does that. A shower does not.
• If someone helps with bathing, the open floor of a shower is easier on both people.
• If the house has one bathroom and one tub and the tub matters to the household, a walk-in tub keeps it.
• If cleaning is already the hard part, build the one with the least grout, the least glass and the fewest seals.

More under accessible living

• Curbless walk-in showers: the complete guide
• Does changing the house actually help?
• Grab bars: where they go, and what holds them