A lanai is the room a Florida house is actually lived in, and it is the one surface that has to work as a floor and as an outdoor deck at the same time — barefoot from the pool on one side, dining chairs and a dog on the other, and the interior floor visible through the sliders the whole way.
Under a roof the sun is not the problem it is on a pool deck. Shade is. A covered floor stays damp longer after rain and after the pressure-washer, and a continuous sealed surface gives algae far less to hold onto than grout lines or paver joints do. It is also where the polished finish earns its place: a lanai floor takes the same polish an interior slab does, and the large panels read as one surface from the kitchen to the screen.
A balcony is the same material with a different question underneath it. The slab is structural, the falls have to carry water to a drain rather than over the edge, and whatever is keeping the room below dry is decided before any topping goes down. Those are not surfacing questions and we do not treat them as ones — they are the conversation that happens on site, first.
One of ours in full: a polished balcony and lanai. The finish most lanais take is polished; where the lanai opens onto the water, the pool deck page carries on from here.
Lanais & Balconies we have poured
- Reads as one floor from the sliders to the screen
- A sealed surface where shade keeps everything damp
- Polished, honed or exposed — the same pour, finished for the room
Code & climate notes
Shade, drainage and what is underneath
The part of a lanai nearest the house sees almost no sun and dries last; the part at the screen sees the weather. One pour can carry two finishes for that reason — a polish where feet and furniture live, more texture toward the pool edge — and the transition is placed where the roof line is, not where it is convenient.
A balcony floor is decided by the slab it sits on. Falls to the drain, the flashing at the door threshold and the waterproofing under the topping are all questions for the structure, and they are answered by looking at it. We will say when a balcony wants a membrane system rather than a topping; SRQ Modern is a Duradek applicator for exactly that case.
Finishes that suit this
Shellcrete lanais & balconies we have poured
Polished Shellcrete balcony and lanai
Sarasota
A polished Shellcrete balcony running to a black cable railing, and a pale lanai floor at the sliding doors of a white clapboard house, both finished flat enough to read as a single plane.
Polished Shellcrete lanai and pool deck
Sarasota
A covered lanai floor polished to a high gloss and laid in large panels that pick up the reflection of the sliding doors, running out to a screened pool deck with a raised ledge carrying a linear fire feature.
Common questions
Can a lanai floor be polished like an interior floor?
Yes — under a roof, it is the finish that earns its place. A lanai floor takes the same mechanical polish an interior slab does, ground through progressively finer grits until it picks up reflections, and the large panels read as one surface from the kitchen to the screen. That gloss is polish, not a coating, so it does not peel.
It belongs under cover for the same reason it belongs indoors: a polished surface is the least textured of the three, and nobody should be stepping onto it wet out of a pool. Where the lanai opens onto the water, the finish changes at the roof line, and the pool deck page carries on from there.
What happens to the existing lanai floor — tile or pavers?
They come up. A topping bonds to concrete, not to a glazed tile face or to units on sand, so tile is removed back to the slab and pavers are lifted off it. Over a sound existing slab — which most lanais have under whatever is on top — the pour goes straight down; where there is no slab, one is poured first.
What that buys you is the thing tile and pavers cannot give a covered floor: a continuous sealed surface with no grout lines or joints for algae to hold onto in a room that stays damp after every rain and every pressure-wash.
Why do you ask about waterproofing before quoting a balcony?
Because a balcony is a structural slab with a room underneath it, and a topping is the last thing that goes on, not the first. The falls have to carry water to a drain rather than over the edge, and whatever is keeping the room below dry — the membrane, the flashing, the drain itself — is decided and sound before any surface is poured over it.
Those are not surfacing questions, and we do not treat them as ones. A topping over a failed membrane hides the problem and makes the repair bigger; it is the conversation that happens on site, first, and sometimes the answer is that somebody else goes before we do.
Will algae come back on a covered floor?
Far less, and more slowly, because there is far less for it to hold onto. Under a roof, shade rather than sun is the problem: a covered floor stays damp longer after rain, and grout lines and paver joints are where algae takes hold first. One continuous surface, sealed with a penetrating sealer, gives it almost nothing.
What keeps it that way is mostly a hose. Rinse the floor, get to leaves and organic stains early, and do not use acid — muriatic acid etches the shell faster than the matrix around it and changes the texture for good. Sealing a shell deck has the rest of the care list.
On film
A balcony, just finished
0:27A Shellcrete balcony on Anna Maria Island
A new build on Anna Maria: the house from the street, the covered balcony with its Shellcrete floor just finished, the framing details and the neighbourhood from the upper deck.
