Kool deck resurfacing in South Florida
A chalking Kool deck cannot be patched. It gets ground back to sound concrete and resurfaced from 8 dollars per sq ft installed, in 1 to 3 days on a typical deck, with no demolition and no dumpster.
A chalking Kool deck cannot be repaired in place. The acrylic and cement topping has lost its bond to the slab, so anything coated over it fails with it. It can be resurfaced. The failed topping is ground back to sound concrete, cracks are treated, the slab is primed, and a new seamless layer is poured on top. In South Florida that starts at 8 dollars per sq ft installed, takes 1 to 3 days on a typical deck, and needs no demolition and no dumpster.
We pour over your existing deck.Nothing is dug up and your sprinkler lines stay where they are.
Kool deck is a registered product of Mortex, and for fifty years it was the default pool deck finish in Florida. It is also the surface most often failing right now, because the ones poured in the eighties and nineties have reached the end of their life at the same time.
Tell chalking from delamination in 2 minutes
These are different failures with different answers, and you can diagnose both yourself before anyone quotes you.
Chalking. Drag a thumb across the dry surface. If it comes away with fine pale dust, the binder in the topping has broken down under UV. The texture is washing off a little more with every rain. The slab underneath is usually still fine.
Delamination. Tap across the deck with a coin or a screwdriver handle. Sound concrete rings solid. A hollow, drummy note means the topping has released from the slab and is sitting on air. Press hard on a hollow area and you may feel it flex.
The tape test. Press a strip of packing tape firmly onto a clean dry patch and rip it off. If it lifts a layer of the topping, the bond is gone.
Chalking on a sound slab is the easy case. Widespread delamination means more grinding, and a slab that has settled differentially or is contaminated with oil or an old sealer may not be worth resurfacing at all. We say so at the estimate rather than after.
Why painting over it fails
The instinct is to buy a bucket of deck coating and roll it on. It fails for a simple reason. A coating is only as good as what it is stuck to. If the Kool deck under it is chalking, the new coating bonds to loose dust, and the whole thing lifts in sheets within a season or two.
The same applies to a second layer of Kool deck over the first. The product was designed to go onto fresh concrete, not onto a failed topping.
What resurfacing actually involves
Grind the failed topping back until the surface rings solid everywhere. Cut out and rebuild any crumbling edges at the coping and the expansion joints. Treat and bridge cracks so they do not telegraph through. Prime the slab, and check it for trapped moisture first, because South Florida slabs sit on a high water table and a slab giving off vapour will push a coating off.
Then pour the new surface. Poured rubber goes down at 0.4 to 0.75 inch and is soft, permeable and cooler underfoot. Stone carpet goes down at 0.3 to 0.6 inch and looks like natural pebble. Both are seamless, both drain through, both go over the slab you already have.
What it costs and how long it takes
From 8 dollars per sq ft installed, with the number depending on how much grinding the old topping needs and how many colors you pick. A typical deck is 1 to 3 days, walkable in 24 to 48 hours and at full strength on day 7.
Compare that with the alternative most people are quoted. Tear out the deck and lay pavers, at 25 to 40 dollars per sq ft, 2 to 4 weeks, a dumpster in the driveway and a permit in most Broward cities.
The part nobody mentions
Kool deck was sold on staying cooler than plain concrete, and it does. But by the time it is chalking it has lost the texture that did the work. On a 91 degree afternoon a bare concrete deck hands your foot about 155 degrees. A light sand poured rubber deck hands it about 99. The full table with the arithmetic is here.
Questions we get
Can you resurface over Kool deck without removing it?
Only where it is still sound and bonded. Anywhere it is chalking or drummy it comes off first, otherwise the new surface inherits the failure.
Do I need a permit?
In most Broward and Miami‑Dade cities a like for like resurfacing does not trigger one. We check your municipality before the work and say so in writing.
Will it crack again?
Cracks come from the slab, not the surface. A poured elastic layer bridges hairline movement instead of telegraphing it, which is why the same crack that returns through paint every year stops showing.
Is Kool deck still made?
Yes, by Mortex. We are not affiliated with them and we do not install it. We name it here because it is what most South Florida decks are surfaced with, and it is the thing people are trying to fix.
Does Kool deck peel?
Yes, and it fails in 2 different ways. Chalking is the surface powdering off, so your hand comes away white and the color goes flat. Delamination is the topping letting go of the slab underneath, and it sounds hollow when you tap it with a knuckle or a broom handle. Sun, chlorine splash and daily heat cycling drive both. Chalking can be lived with for a season. A drummy Kool deck cannot be patched or painted, because anything laid over it fails with it, so it gets ground back to sound concrete and resurfaced from 8 dollars per sq ft installed.
How long does Kool deck last?
Kool deck was the default Florida pool deck finish for fifty years, and how long a given deck holds depends on the slab it sits on rather than on the brand. It is a thin acrylic and cement topping troweled over concrete, so it lives and dies by its bond. Sun, chlorine splash and daily heat cycling work it loose at the edges and around the coping first. Once it chalks under your hand or sounds hollow when tapped, it is finished as a surface. B-Cool grinds it back to sound concrete and resurfaces from 8 dollars per sq ft installed in 1 to 3 days.
How much does Kool deck cost?
On a deck you already own, the number that matters is not new Kool deck, it is what the failure costs to fix, and that starts at 8 dollars per sq ft installed. Kool deck is a Mortex product troweled onto fresh concrete, so it is normally quoted as part of a new pour rather than as a standalone job on an existing slab. A chalking or drummy Kool deck cannot be patched or painted. It gets ground back to sound concrete and resurfaced in 1 to 3 days, with no demolition and no dumpster, under a 2 year workmanship warranty.
Is Kool deck worth it?
Kool deck earned its place over fifty years as the default Florida pool deck finish, and on a first pour it still gives texture and a lighter color than bare concrete. What it cannot do is stay bonded forever. The second time it chalks or goes drummy you are paying to grind the same slab twice. Our field readings put poured rubber surfacing at 99 F on an afternoon when bare concrete read 155 F, and poured rubber bonds straight over the existing slab from 8 dollars per sq ft installed, in 1 to 3 days, with a 2 year workmanship warranty.