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Usually, yes. A curbless shower is almost always possible in an existing bathroom. What determines how involved it gets is what sits under the floor. The shower floor has to drop below the level of the surrounding room so water runs to the drain instead of out into the bathroom, and how we create that drop depends on whether you are over floor joists or on a concrete slab.
This question comes up more every year, usually from homeowners who plan to stay in their house and want a shower they can walk straight into. It is a good instinct. It is also a project where the planning matters more than the tile selection, so here is what actually decides whether it will work in your bathroom.
The Floor Structure Decides Everything
A standard shower uses a curb as a dam. Remove the curb and the shower pan itself has to sit lower than the bathroom floor, with enough fall across it to move water to the drain. That means finding one to two inches of depth that does not currently exist.
Over a Wood Framed Floor
On an upper floor or over a crawl space, we cut out the subfloor in the shower footprint and reset it lower, resting on blocking or brackets fastened to the sides of the joists rather than on top of them. That recovers close to an inch without touching the structure. When more drop is needed, the options are building up the rest of the bathroom floor to meet the new height or, occasionally, engineered modifications to the framing.
What we do not do is notch the tops of joists to create slope. That weakens the framing in the exact place it carries load, and it is not something to improvise on a house that is already standing. Deep joists give you room to work. Shallow joists in an older home give you less, and that is where the design has to get creative.
On a Concrete Slab
On a slab, the shower area gets saw cut, the concrete is removed, the plumbing is set, and a new lower section is poured. It sounds dramatic and it is a well established process. Slab work is dusty and loud for a couple of days, and it is the more disruptive path, but it produces a clean result and a shower with no threshold at all.
In a basement bathroom, the same excavation gets you access to the drain. If the drain sits below the main sewer line, that bathroom needs a pump system, which is common in basement remodeling and needs to be planned from the start rather than discovered later.
Where the Drain Sits Changes the Design
A center point drain requires the floor to slope toward the middle from all four directions. That works, and with large format tile it means a lot of cuts to make the pitch look intentional.
A linear drain along one wall or at the entry lets the entire floor slope in a single direction. That is usually the better choice in a curbless shower for two reasons. It handles big tile cleanly, and it lets us pitch the floor away from the bathroom, which helps keep water where it belongs. If the existing drain is in the middle of the footprint, moving it is part of the job either way, so it is worth deciding on the drain type before anyone opens the floor.
Waterproofing Is the Whole Job
With a curb, the curb catches your mistakes. Without one, the waterproofing has to be right, because there is no second line of defense. The membrane has to run continuously across the shower floor, up the walls, and out past the opening into the bathroom floor, so any water that travels beyond the shower footprint is still on top of a waterproof surface.
That is the part homeowners cannot inspect after the fact, and it is where corners get cut. When we open up a failing curbless shower, the tile is rarely the problem. The transition detail at the entry is. Anyone building one of these should be using a full waterproofing system, sealing every corner and penetration, and water testing before tile goes down.
How Much Room a Curbless Shower Needs
Size matters more without a curb than with one. A curb keeps water contained in a small space. An open shower relies on distance, slope, and glass placement instead.
Depth Keeps Water Off the Bathroom Floor
The showerhead should be far enough from the opening that spray and splash never reach it. In a tight footprint that means positioning the valve and head on the wall opposite the entry and using a glass panel to block the direct path out. A hand shower on a slide bar helps too, since it keeps water aimed down rather than across the room.
If your bathroom is small to begin with, our guide on making a small bathroom feel bigger covers how to buy back the room a curbless shower wants.
Entry Width Is Worth Planning Around
One of the main reasons to go curbless is unobstructed entry, so do not undercut it with a narrow opening. A 36 inch clear opening accommodates a walker or a wheelchair. Even if that is not the situation today, building the opening wide costs nothing extra while the walls are open and matters enormously if circumstances change.
The Aging in Place Case for Doing It Now
Most people asking about curbless showers are not dealing with a mobility issue yet. They are planning ahead, and that is exactly the right time. Stepping over a curb is a small thing until it is not, and a shower curb is one of the most common places people fall in their own homes.
The related decisions are worth making at the same time, because they are simple during construction and awkward as retrofits. Blocking in the walls for grab bars, whether or not you install bars now. A bench built into the shower. A hand shower. Lever handles. A comfort height toilet. None of it has to look clinical. Done well, it just reads as a well designed bathroom that happens to work for everyone. Our aging in place remodeling work is built around that idea, and you can see how it comes together in this accessible bathroom project.
Older Homes in Prairie Village, Waldo, and Brookside
The homes south of the Plaza and across Prairie Village are where this question gets interesting. Brookside and Waldo bungalows and cape cods, and the postwar ranches through Prairie Village, were built with small bathrooms, cast iron tubs, and tile set over mortar beds. Those floors are heavier and thicker than what is in a newer house, and the framing underneath is not always what a modern plan would assume.
That is not a reason to rule it out. It is a reason to open the floor and look before promising a specific detail. In a lot of these houses, removing an old tub gives us the footprint and the demolition access we need at the same time. On a main floor over a basement, we also get to see the joists from below, which makes the recess much easier to plan. Our comparison of walk-in showers versus bathtubs is a useful read if you are weighing whether the tub should stay at all.
One thing to watch in older homes with one full bath: a curbless conversion takes the only bathroom offline for longer than a standard shower swap. Plan around that before the schedule is set.
When a Low Curb Is the Smarter Choice
I would rather talk a homeowner into the right shower than sell them the one they asked for. There are cases where fully curbless is not the best answer. A second floor bathroom with shallow joists and a finished ceiling below, where creating the drop means rebuilding more of the floor than the project justifies. A very small shower footprint where the water simply has nowhere to go. A bathroom where the floor level cannot be raised to meet the pan without creating a step at the door, which trades one trip hazard for another.
In those situations, a low profile curb of a half inch or so, or a sloped ramp entry, gets you nearly all of the accessibility with far less structural work. It is a real option, not a compromise, and it is what I recommend when the framing is fighting us.
Settle the Details Before Demolition
Curbless showers are unforgiving of decisions made on the fly. The drain type, the recess method, the waterproofing system, the glass layout, and the entry width all interlock, and each one limits the others. We work through all of it during planning, which is what our design process is for. If this is part of a broader plan to stay in your home comfortably, our article on making a house more livable long term covers the rest of the house.
Find Out What Your Bathroom Can Support
At City Wide Remodelers, we have been building showers for Kansas City homeowners since 1955, and curbless conversions are a regular part of our bathroom remodeling work. If you want to know what is possible under your floor, schedule a free consultation, call us at (816) 942-1993, or email admin@citywideremodelers.com, and we will look at the structure and give you a straight answer.
