October 24, 2026 · RestoFlo · South Florida
Direct answer: Yes, a curbless shower may be possible over a concrete slab, but removing the curb alone does not create a workable shower. The project needs enough height for a floor sloped to a compatible drain, an approved way to connect the existing waste line, and waterproofing that continues across every area exposed to water. A slab recess is not automatically safe or necessary; raising the surrounding floor or using a designed transition may be alternatives. Verify the actual slab, plumbing, elevations, product instructions, and local requirements before committing to a layout.[1][2][3]
A flush entry can look beautifully simple. Under the tile, it is a coordinated construction problem. This guide is for South Florida homeowners planning a bathroom remodel on a concrete floor—not a do-it-yourself instruction to saw a slab or alter plumbing. It focuses on the slab-specific feasibility decision, rather than repeating our broader aging-in-place bathroom planning guide or our shower-waterproofing checklist.
First determine whether the slab can support the floor-height plan
A shower without a curb still needs a fall toward the drain. Over an existing slab, the shower build-up and drain cannot simply occupy the same height as the untouched bathroom floor without a deliberate elevation strategy. Manufacturer guidance describes three general routes: recess the shower area where the structure allows; use a designed tray/ramp transition; or build up the surrounding bathroom floor to meet the shower perimeter.[1][2] A prefabricated floor-recessing bracket made for wood joists is not a method for cutting a concrete slab—the slab assembly needs its own design.[1]
Before pricing a finish package, ask for an existing-versus-proposed floor section. It should show the slab, any recess or added build-up, shower perimeter, tile and setting layers, drain body, slope, bathroom doorway, and transition to adjacent rooms. Check that the plan does not solve the shower entry by creating an awkward rise elsewhere. A truly step-free entry and a ramped entry are different outcomes; describe the chosen one accurately.
Do not authorize blind slab cutting or trenching. Schluter specifically cautions that recessing must preserve structural integrity and may need a qualified design professional; it names post-tension concrete as an example where raising the bathroom floor may be an alternative.[2] Confirm what the actual slab contains and who must assess any proposed opening before work starts. In a condominium, also check the association's alteration rules and shared-assembly constraints. No online article can certify that a particular slab can be modified.
Trace the water path and waste-line route before choosing the drain
The slope is not decorative: it moves shower water to the drain. As one product-specific example, LATICRETE's concrete-installation instructions describe forming a 1/4-inch-per-foot fall to its bonding-flange drain; its mortar thicknesses and flange elevations vary by bonded or unbonded method.[3] That is not a universal specification for every shower, drain, or jurisdiction. Have the installer document the actual selected system, applicable code interpretation, usable shower dimensions, finished elevations, and planned slope before a pan or tile is ordered.
A point drain and a linear drain can both be considered for curbless work; neither independently solves a high trap, inconvenient waste-line location, inadequate depth, or wrong waterproofing connection. Schluter lists both point and linear drain options and emphasizes integrated slope, drainage, and waterproofing.[1][2] Confirm the existing drain and trap location, available pipe route and connection, selected outlet material, and whether the drain can be supported at the proposed elevation. LATICRETE's example requires the bonding flange to be supported and connected compatibly to the waste line.[3] Plumbing routing and any necessary slab work should be evaluated by the appropriate qualified trades—not assumed from the location of the old tub drain.
A large opening, direct spray toward the entrance, or insufficient shower depth can send water beyond the wet area even when the floor slopes. Decide showerhead orientation, glass or splash-control strategy, drain position, and where the wet-to-dry line really lies together. A linear drain is a layout option, not an automatic promise of a dry bathroom.[1]
Waterproof the transition, not just the tile inside the shower
Without a curb, the vulnerable boundary extends into the room. The specified assembly should connect the floor and wall membrane, drain flange, corners, penetrations, and shower entry, and cover the adjacent floor wherever water can reasonably reach. Schluter advises waterproofing all areas subject to exposure in curbless work; its guidance also emphasizes water management beyond a narrow shower footprint.[1] Tile and grout are finishes, not a substitute for that assembly. For a fuller discussion of membranes and pre-tile inspection, see what belongs behind shower tile.
Ask the remodel team to identify the specific substrate, membrane, drain, sealants, connection details, cure sequence, and wet-area extent in writing. Do not assume that a thin layer of mortar over any slab, an arbitrary linear drain, and a different manufacturer's membrane form a compatible system. LATICRETE's concrete details distinguish bonded and unbonded beds and call for its selected drain/membrane method; another manufacturer's assembly can differ.[3]
Before tile covers the work, agree on the applicable inspection and test plan. Schluter describes a shower water test as a pre-tile quality check and notes that a barrier-free entry needs a temporary dam for that test; its waiting guidance applies to its own membrane system, not all products.[4] Have the installer and relevant authority confirm whether and how the chosen assembly will be tested. Save pre-tile photographs of the drain flange, corners, entry and exposed floor, along with the selected product instructions and results.
South Florida planning: ventilation, approvals, and the real scope
Waterproofing controls liquid water; a bathroom exhaust plan deals with moisture in the air. EPA recommends checking that the bathroom fan actually exhausts adequately to the outside, not into an attic or another indoor space.[5] In a humid South Florida bathroom, ask whether existing ventilation works while planning the shower, but do not treat a fan as a substitute for a sealed drain and membrane.
Define the construction scope before promising a price or start date: slab/structural review if needed; drain and trap investigation; proposed floor elevations; plumbing and ventilation changes; chosen waterproofing assembly; splash control; tile and glass; pre-tile verification; and contingencies for hidden conditions. The RestoFlo bathroom-remodeling service page describes our planned-remodeling offering. For the separate question of which approvals apply, see our South Florida bathroom permit guide and ask the building department for the property's exact address. Florida's Building Commission provides the state code-resource entry point, but the applicable determination depends on the property and proposed work.[6] Do not assume every cosmetic change needs a permit, or that a slab cut and drain relocation are exempt. Condo association approval, if applicable, is a separate process.
What to ask at an on-site assessment
- What is known—and still unknown—about the slab, any reinforcement or post-tensioning, and the permissible depth of alteration?
- Where are the drain, trap, waste route, and usable connection point? What investigation is needed before committing to a drain type?
- Can the team draw a floor section showing the shower's slope and assembly thickness, bathroom finish elevation, doorway and adjacent-room transition?
- Which complete waterproofing method and drain connection will be installed, and how far beyond the shower entry will protection extend?
- How will spray be contained, and which test, inspection and jurisdiction/association approvals apply to this scope?
Bring photos and approximate room measurements, but expect the final answer to depend on field verification. If an assessment shows that a true flush transition is impractical without an unacceptable slab modification or a new floor-height problem, ask for a revised layout or a clearly described low-threshold alternative rather than an unqualified “curbless” promise.
Plan the remodel with RestoFlo. Call (754) 289-4815 or request a free assessment to discuss a South Florida bathroom-remodeling scope. An assessment is a starting point; feasibility, design, approvals and installed performance depend on the property's actual conditions and the selected system.
Frequently asked questions
Can a curbless shower be built on an existing concrete slab?
Possibly. The team must resolve a sloped shower floor, drain/waste connection, waterproofing, and the finished-floor transition. Depending on the verified slab and room, options may include an approved recess, a designed ramp, or raising the surrounding floor. A site-specific assessment—not the slab label alone—determines feasibility.[1][2]
Does a concrete slab have to be cut for a curbless shower?
No. Some designs raise the bathroom floor or use a designed transition instead. If cutting is proposed, the slab's construction and structural constraints must first be assessed; post-tension concrete is one reason not to assume recessing is appropriate.[2]
Is a linear drain required for a curbless shower?
No. Compatible point and linear drains are both used in curbless systems. Drain selection must suit the planned slope, plumbing route, finished elevation and membrane connection; a linear grate by itself does not guarantee water containment.[1][2]
How far should waterproofing extend outside a curbless shower?
Cover all areas expected to be exposed to water under the selected system, including the entry and adjacent floor where splash may reach. The exact boundary depends on spray, enclosure, layout, product instructions and project requirements; do not stop the membrane at an arbitrary tile line.[1]
Should a curbless shower be water-tested before tile?
Ask for the test and inspection method appropriate to the selected system and local requirements. Schluter describes a pre-tile water test for its system and notes that a barrier-free entrance needs a temporary dam; its cure and testing details should not be imposed on unrelated products.[4]
Sources
[1] https://www.schluter.com/schluter-us/en_US/curbless-shower-systems-and-solutions [2] https://www.schluter.com/schluter-us/en_US/blog-the-benefits-of-a-curbless-shower [3] https://www.laticrete.com/blog/2024/december/how-to-install-a-shower-drain-in-concrete [4] https://www.schluter.com/schluter-us/en_US/faq/shower-system-water-test-how-to [5] https://www.epa.gov/indoor-air-quality-iaq/remodeling-your-home-and-indoor-air-quality [6] https://www.floridabuilding.org/bc/bc_default.aspx
