Atlantic hurricane season runs June 1 through November 30, and in this part of Louisiana the significant rainfall events are not limited to named storms. Concrete does not care what the weather system was called — it cares how much water it absorbs and how long it stays saturated. The five signs below are the ones worth walking outside and checking, because each of them tells you the slab has stopped shedding water.
The five signs, and what each one actually means
| Sign | What is happening | What it means for the work |
|---|---|---|
| 1. Water darkens the slab instead of beading on it | An intact sealer keeps water sitting on the surface as droplets. When water soaks in within a few seconds and leaves a dark patch, the pore structure is open and the slab is absorbing everything that lands on it. | The most reliable single indicator. If a splash of water disappears into the concrete, whatever sealer was there has worn off. |
| 2. The surface dusts or feels sandy underfoot | The cement paste at the wearing surface has eroded, exposing fine aggregate. Rain, foot traffic, and pressure washing all accelerate it once it starts. | Dusting concrete needs cleaning and often a densifier or resurfacing before a sealer, because a sealer bonded to a weak surface fails with that surface. |
| 3. Hairline cracks have widened, or map cracking has appeared | Water entering a crack keeps working. Each wet-dry cycle carries fines out and each cold snap can freeze water inside the crack, and freezing water expands by roughly nine percent. | Cracks get routed, cleaned, and filled before sealing. Sealing over an open crack traps water in the worst possible place. |
| 4. White efflorescence bloom keeps coming back | Water moving through the slab dissolves mineral salts and deposits them at the surface as it evaporates. The bloom is a symptom of moisture transport, not a stain. | Identify the water source first. A breathable penetrating sealer tolerates some vapor movement; a film-forming sealer over an actively wet slab will blush or peel. |
| 5. Mildew, black streaking, or leaf tannin returns within days of cleaning | Organics feed on moisture held in open pores. If the slab stays damp below the surface, biological staining reestablishes almost immediately after a wash. | Reducing absorption is what breaks the cycle. Cleaning alone treats the symptom for a week. |
The thirty-second test that settles it
Take a cup of water to a clean, dry section of the driveway or patio and pour it out. Sound sealer holds the water on the surface as beads or a shallow puddle, and the concrete under it stays the same color. A slab that needs sealing pulls the water straight in and turns visibly dark within a few seconds.
Do it in at least three places — a tire path, an area under an overhang, and a spot near the edge. Sealer wears fastest where traffic and sun are heaviest, so a driveway can be fully absorbing in the wheel tracks while the protected edges still bead. Uneven results are normal and they tell you where the wear is.
Which sealer does which job
Sealer is not one product. The choice comes down to whether you need the concrete to stop absorbing, to stop staining, or to look different — and to whether the slab is passing vapor from below:
| Type | How it works | What it protects against | Installed price |
|---|---|---|---|
| Silane / siloxane penetrating sealer | Reacts inside the pore structure to line the capillaries with a hydrophobic layer. It changes how the concrete absorbs water without forming a film on top. | Water absorption, freeze-thaw damage, salt and de-icer ingress, efflorescence severity. Leaves the appearance essentially unchanged. | $2–$4 / sq ft |
| Film-forming acrylic sealer | Cures as a thin film on the surface. Wet-look and satin finishes come from this category, and it darkens and enriches the concrete. | Surface staining, dusting, UV fading of decorative concrete. Wears at traffic paths and needs the most frequent renewal. | $3–$6 / sq ft |
| Urethane or epoxy sealer | A tougher, chemically cured film. Usually specified for covered or interior surfaces rather than open exterior slabs. | Abrasion, chemicals, and hot-tire contact. Less breathable, so slab moisture has to be understood first. | $3–$6 / sq ft |
| Resurfacing (when sealing is not enough) | A cementitious overlay rebuilds the wearing surface rather than protecting the existing one. Used where the top layer has already eroded or spalled. | Restores a sound, uniform surface that a sealer can then be applied to. Also corrects minor surface irregularity. | $4–$9 / sq ft |
Sealing is the lowest-cost way to protect concrete you are otherwise happy with. Resurfacing costs more because it rebuilds the wearing surface rather than just protecting it. Crack and spall repair is quoted after assessment. Full detail on scope is on our concrete sealing and resurfacing page.
One technical point is worth understanding before you choose. A penetrating sealer leaves the concrete breathable, so vapor moving up through a slab can still escape. A film-forming sealer does not, which is why an actively wet slab can push a film loose or leave it looking cloudy. On slab-on-grade concrete in this climate that distinction matters — it is the same vapor-drive mechanism explained in how Louisiana humidity affects concrete floors.
Why storm season is the deadline in South Louisiana
Rainfall totals here are high enough that exterior concrete spends a meaningful part of the year wet, and hurricane season concentrates the worst of it. What a storm does to an unsealed slab is a sequence: the concrete saturates, runoff carries leaf tannin and soil iron and oil into open pores, debris scours the softened surface, and the slab then stays damp long enough for mildew and streaking to establish. Repeated across several seasons, that is the difference between concrete that looks fifteen years old and concrete that looks thirty.
Flooding is the extreme version, and this area has a reference point. The August 2016 flood put standing water across Livingston Parish, Denham Springs, and Central, and slabs that sit under water take on moisture that does not leave on a homeowner's schedule. Sealing does not prevent that, and no one should claim it does. What sealing changes is the ordinary case: routine heavy rain, standing water at a low spot, runoff sheeting across a driveway in July.
Winter matters too, in a way people underestimate this far south. A hard freeze after a wet stretch puts water inside the pore structure of a saturated slab, and water expands as it freezes. Concrete that was absorbing all autumn has water in it when the cold front arrives, and surface popouts and spalling are the result — damage most homeowners notice in spring and blame on the summer sun.
The same logic applies at the garage entry, where exterior concrete meets an interior slab and water gets tracked or driven inside. A sealed apron and a coated garage floor are two halves of the same job, which is why homeowners often pair sealing with garage floor coatings.
What sealing does and does not buy you
Saturated concrete is weaker concrete
A slab absorbed to capacity has less resistance to freeze-thaw damage, surface spalling, and the abrasion of debris dragged across it. Reducing absorption is the cheapest structural favor you can do a driveway.
Storm water carries staining agents
Runoff arrives loaded with leaf and pine-straw tannin, iron from soil and metal, and oil lifted off pavement. On unsealed concrete those soak in on contact; on sealed concrete most stays available to be rinsed off.
Cleanup is faster on a sealed slab
The difference between a driveway you pressure wash once and one that keeps a shadow of every stain is largely whether it was absorbing at the time.
Sealing is not waterproofing
A sealer reduces absorption and staining. It does not stop flooding, redirect runoff, correct grade, or repair structural cracking. Anyone claiming otherwise is overselling the product.
Getting the timing right
Sealer needs conditions, not just a free Saturday. The slab has to be dry through its surface pores rather than merely dry to the touch, which after a soaking rain means waiting more than a day. Surface temperature has to sit inside the product range, and there has to be a rain-free window long enough for penetration or cure. New concrete needs to reach a minimum cure age before it takes a sealer at all.
Practically, spring is the sensible time to do this work here: the slab has dried out from winter, dew points have not peaked, and you are ahead of the June 1 start of hurricane season. Fall is the second-best window. Squeezing it in during a humid August stretch, or in the days before a forecast, is how a sealer ends up blotchy.
Repair work goes first. Cracks get routed and filled, spalls get patched, and stains get cleaned before a drop of sealer goes down — sealing over a stain locks it in permanently. If the surface is too far gone for that sequence, resurfacing is the honest recommendation instead.
Frequently asked questions
How do I know if my concrete still has sealer on it?
Pour a cup of water on a clean, dry section and watch it for thirty seconds. If it beads up or sits as a puddle, a sealer is still working. If it soaks in and leaves a dark patch within a few seconds, the slab is absorbing and it is time to reseal. Check two or three spots, including a traffic path and a protected edge, because sealer wears unevenly.
How often does concrete need to be resealed in Louisiana?
Penetrating sealers on exterior concrete generally hold up for a few years before absorption returns, and film-forming sealers need renewal sooner because UV and traffic wear the film. Gulf South heat, UV load, and rainfall put local concrete at the shorter end of published intervals, so the water test matters more than the calendar. Covered surfaces last considerably longer than an open driveway.
Can concrete be sealed right before a storm?
No, and trying is a waste of material. Sealers need a dry slab, a surface temperature inside the product range, and a rain-free window while the product penetrates or cures. Applying to damp concrete or getting rained on during cure produces blushing, poor penetration, or a sealer that never bonds. Plan sealing for a settled dry stretch, not the two days before a forecast.
Should I seal or resurface?
Seal if the surface is sound and you are protecting it. Resurface if the wearing surface is already gone — heavy dusting, exposed aggregate across broad areas, spalling, or popouts. A sealer applied over a failing surface fails with it. Resurfacing costs more because it rebuilds the surface rather than protecting what is there.
More answers on prep, sealing, and coatings are on our concrete coatings FAQ. If you are also weighing an interior coating, compare systems in epoxy vs. polyaspartic or price it out in the Baton Rouge cost guide.
Get your concrete looked at before the season
If the water test came back wrong, or you are looking at cracks and staining you would rather not watch get worse, that is a short conversation. Tell us the square footage, what the surface is doing, and whether anything has ever been applied to it, and we will tell you whether it needs sealing, repair, or resurfacing — and what each one costs.
Serving Baton Rouge and the surrounding metro, including Prairieville, Gonzales, Denham Springs, Zachary, Central, Baker, Walker, Port Allen, Addis & Brusly, and St. Gabriel.