Quick answer
How often should concrete be sealed?
Exterior concrete should be sealed every two to three years, with decorative and high-traffic surfaces at the shorter end of that range. Interior floors need resealing every eight to ten years because there's no UV or weather exposure. New concrete should not be sealed until it has cured for at least 28 days. The reliable test is water: if it beads, the sealer is working; if it soaks in, it's time.
- Exterior flatwork
- Every 2–3 years
- Decorative exterior
- Every 2 years
- Interior floors
- Every 8–10 years
- First seal on new work
- 28 days minimum
Sealing is the highest-value maintenance you can do to concrete, and it's also the one most likely to be done badly. Roughly half the sealing problems we're called to look at are the result of someone sealing enthusiastically rather than not sealing at all — too much product, applied to damp concrete, or over an incompatible existing coat.
It's worth understanding what a sealer actually does. Concrete is porous: water, oil, salts, and dirt all migrate into the surface. A sealer either blocks the pores or lines them, reducing that absorption. That reduces staining, slows surface wear, limits the movement of moisture through the slab, and — on decorative work — keeps colour looking the way it did on day one.
Sealing intervals by surface
How often, by surface
| Surface | Interval | Notes |
|---|---|---|
| Broom-finished driveway | 2–3 years | The parking strip will wear first. Reseal the whole slab rather than spot-treating. |
| Broom-finished patio or walkway | 3 years | Lower traffic than a driveway. Shaded areas can stretch further. |
| Stamped or coloured exterior | 2 years | The sealer carries the appearance, not just protection. Don't stretch this one. |
| Exposed aggregate | 2–3 years | Sealing wets the stone and brings out colour. Unsealed looks noticeably duller. |
| Pool deck | 2 years | Constant wetting plus pool chemistry. Always with a grit additive. |
| Garage floor | 3–5 years | Protected from UV but exposed to hot tyres and chemicals. Use a hot-tyre-rated product. |
| Interior stained or polished floor | 8–10 years | No UV, no weather. Often needs only periodic re-polishing or a maintenance coat. |
| Commercial flatwork | 1–3 years | Driven by traffic volume rather than time. Usually part of a scheduled maintenance plan. |
Sealer types, and which to use
Sealers fall into two broad families, and the distinction matters because they behave completely differently.
Penetrating sealers — silanes, siloxanes, and silicates — soak into the concrete and react within the pores. They leave no film and don't change the appearance or the traction of the surface at all. They're the right choice on plain concrete where you want protection without a look, and they're effectively invisible. They also can't peel, because there's nothing on the surface to peel.
Film-forming sealers — acrylics, epoxies, and urethanes — leave a coating on the surface. They enhance colour, add sheen, and give better stain resistance, which is why all decorative work uses them. They're also what can go cloudy, blister, or peel if applied badly, and they need renewing more often because the film wears.
For most homeowners: penetrating on plain grey exterior concrete, acrylic on anything decorative outdoors, and epoxy or urethane on garage and interior floors where chemical resistance matters.
Sealer types compared
| Type | Look | Lifespan | Best for |
|---|---|---|---|
| Penetrating (silane / siloxane) | No change — invisible | 5–10 years | Plain exterior concrete where you want protection without changing appearance or traction. |
| Acrylic (water-based) | Light sheen, mild colour enhancement | 1–3 years | Decorative exterior work. Easy to apply and recoat, low odour. |
| Acrylic (solvent-based) | Stronger colour enhancement and sheen | 1–3 years | Stamped and coloured exterior concrete where colour depth matters most. |
| Polyurethane | Gloss or matte, hard-wearing | 5–10 years | Interior floors and garages. Excellent abrasion and chemical resistance. |
| Epoxy | High gloss, thick film | 5–10 years | Garage and industrial floors. Not UV-stable — indoor use only. |
Applying sealer properly
A reasonable DIY job. Almost all failures come from preparation or from applying too much.
Pick the weather
Dry, 50–90°F, no rain forecast for 24 hours, and ideally out of direct midday sun. A hot slab flashes off solvent before the sealer can penetrate.
Clean thoroughly
Concrete cleaner and a stiff brush, or a pressure washer with a 25–40 degree fan tip kept moving and a foot back. Remove all grease, organic growth, and loose material.
Let it dry completely
24 hours minimum, longer after wet weather. Concrete holds moisture far longer than the surface suggests. This is the step most often rushed and the cause of most cloudy finishes.
Repair first
Fill cracks and re-caulk joints before sealing. Sealing over an open crack traps water in it.
Test compatibility
If you don't know what sealer is already on there, test a hidden patch and wait a full day. Solvent-based over water-based frequently lifts the existing coat.
Two thin coats
Roller or pump sprayer, working in one direction, at the coverage rate on the tin. Second coat perpendicular to the first once touch-dry. Two thin coats always beat one heavy one.
Add grit where needed
A fine polymer grit additive in the final coat on slopes, steps, and anything near water. Invisible underfoot, and it transforms wet traction.
Stay off it
Foot traffic at 24 hours, furniture at 48, vehicles at 72.
Is sealing worth it in California?
It's a fair question, because the strongest argument for sealing elsewhere — freeze-thaw protection — barely applies here. Water in the pores of unsealed concrete freezing and expanding is what destroys surfaces across most of the country, and we get almost none of it.
The local case is different but still real. Sun exposure fades decorative colour, and sealer is the primary defence. Oil and fuel penetrate unsealed concrete within hours and become permanent. Our long dry summers mean dust and grit sit on surfaces and grind into them under traffic. And efflorescence — the white mineral bloom from moisture moving through a slab — is much more manageable on a sealed surface.
So: for plain grey concrete, sealing is genuinely optional and mostly about staining and appearance. For anything decorative, it's not optional at all, because the appearance you paid for depends on it.
Sealing questions
Related reading
Key takeaways
- Exterior concrete every 2–3 years; decorative at the short end; interior floors every 8–10.
- Never seal new concrete before 28 days.
- Use the water test rather than the calendar — different areas wear at different rates.
- Penetrating sealers for plain concrete, film-forming for decorative, epoxy or urethane indoors.
- Two thin coats, applied to fully dry concrete, at the stated coverage rate.
- Add a grit additive to the final coat on slopes, steps, and anything near water.
Still deciding?
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