Concrete Sealing Explained: Why, When and How Often
Concrete is naturally porous, which means it absorbs water, oil, and stains unless it’s protected. Sealing is the single most cost-effective thing you can do to extend the life and appearance of a driveway, path or decorative slab.
Why Concrete Needs Sealing
Unsealed concrete is porous — it absorbs water, oil, tyre marks and general staining, and repeated moisture penetration contributes to surface deterioration, efflorescence and, over time in the wrong conditions, freeze-thaw-style cracking (relevant even in Melbourne’s milder climate through repeated wet-dry cycles). A sealer forms a protective barrier that keeps moisture, oil and staining agents from soaking into the surface, and for decorative finishes like exposed aggregate or coloured concrete, it also enhances and protects the colour.
Types of Concrete Sealer
Penetrating sealers soak into the concrete itself and protect from within without significantly changing the surface appearance — a good choice where you want protection without a glossy look. Topical (film-forming) sealers sit on top of the surface, offering a wet-look sheen that enhances colour and texture, popular on decorative and exposed aggregate finishes, but they wear from foot and vehicle traffic and need more frequent reapplication. The right choice depends on the look you want and how much traffic the surface handles.
When to Seal New and Existing Concrete
New concrete needs to cure fully before sealing — sealing too early can trap moisture in the slab and cause problems rather than prevent them. As a general guide, new concrete is typically ready for sealing after around 28 days of curing, though this varies with mix design, weather and finish. Existing concrete can be sealed at any time as part of routine maintenance, ideally before visible wear, staining or surface deterioration sets in.
How Often Resealing Is Needed
Resealing frequency depends on the sealer type, traffic levels and exposure to sun and weather. As a rough guide, driveways and high-traffic areas may need resealing every 2-3 years, while less exposed decorative areas can go longer between applications. UV exposure, vehicle traffic and harsh cleaning products all accelerate sealer breakdown, so a driveway in full sun will typically need attention sooner than a shaded path.
Signs Your Concrete Needs Resealing
Watch for water no longer beading on the surface (soaking in instead), a dull or faded appearance where the surface used to have sheen, visible staining that wasn’t wiping away easily, and any powdery or chalky surface texture. These are all signs the existing sealer has broken down and the concrete is exposed again — the earlier you catch this, the less cumulative damage the surface takes before it’s resealed.
What Sealing Won’t Fix
It’s worth being clear about what sealing can’t do: it won’t fix existing structural cracking, won’t correct drainage or base problems, and won’t disguise significant surface damage that’s already occurred. Sealing is protective maintenance, not a repair — significant existing damage needs proper concrete repair or resurfacing work first, not just a fresh coat of sealer.
Recently Completed Projects
We complete residential and commercial concrete, excavation and foundation projects across Melbourne every week. Explore our project gallery to see the range of work we deliver.
Frequently Asked Questions
How soon after pouring can new concrete be sealed?
Typically around 28 days, once the concrete has cured sufficiently — sealing too early can trap moisture in the slab and cause problems.
Does sealing change the colour of concrete?
Penetrating sealers generally don’t change the look much, while topical sealers often add a wet-look sheen that enhances and deepens existing colour, particularly on decorative and exposed aggregate finishes.
How often should a driveway be resealed?
As a general guide, every 2-3 years for high-traffic, sun-exposed driveways, though this varies with the sealer used and local conditions.
Can sealing fix cracked concrete?
No — sealing is protective maintenance for sound concrete, not a repair for existing cracks or structural damage.
Is sealing worth it for a plain concrete driveway?
Yes — sealing protects any concrete surface from staining, moisture damage and surface wear, extending its practical lifespan regardless of the finish.
Related Guides, Calculators & Services
Ready To Get Started?
Request a free, no-obligation quote and our team will assess your site and provide an accurate, fixed price.
