How to Seal & Maintain a Concrete Driveway (2026)

Australia's climate is hard on concrete. In Queensland and the Northern Territory, intense UV and tropical downpours accelerate surface degradation. In Melbourne and Hobart, freeze-thaw cycles during winter can open hairline cracks. Even in Perth's dry summers, prolonged UV exposure chalks and fades an unsealed decorative slab quickly.

Sealing is not just cosmetic. It reduces carbonation of the concrete, which protects any steel reinforcement underneath from corrosion. For coloured, stencilled or exposed aggregate finishes, it also preserves the look you paid for. A plain broom-finished slab benefits just as much structurally, even if the visual difference is less dramatic.

The other half of the equation is routine maintenance. Sealing every three to five years and cleaning the surface annually is far cheaper than grinding out and replacing a badly degraded slab.

Not all sealers suit all situations. The two broad categories you will encounter at trade suppliers and hardware stores are penetrating sealers and film-forming sealers. Each has a clear role.

Penetrating Sealers (Silane/Siloxane)

These soak into the concrete matrix and repel water and salts without changing the surface appearance. They are the best choice for plain or broom-finished driveways where you want invisible protection. They last five to ten years in most Australian conditions and do not peel or require stripping before recoating.

Acrylic Film-Forming Sealers

Water-based or solvent-based acrylics sit on top of the surface and add a gloss or satin sheen. They are commonly used on exposed aggregate and coloured concrete to enhance the finish. Solvent-based acrylics are more durable but produce strong fumes during application and dry time. Water-based versions are easier to use for a DIYer. Expect to recoat every two to three years in high-UV states like Queensland and Western Australia.

Polyurethane and Epoxy Sealers

These are heavy-duty film formers more common indoors or in commercial settings. On an outdoor driveway they can become slippery when wet, which is a safety hazard. Avoid them for external use unless they carry a slip-resistant additive and you have checked with the manufacturer.

Good preparation is where most DIY sealing jobs succeed or fail. Rushing this stage is the single biggest mistake people make.

Step 1. Clear and Clean the Driveway

Move vehicles, pots and anything else off the slab. Sweep away all loose debris. Use a stiff broom or a leaf blower to get into the textured surface of a broom finish.

Step 2. Degrease Oil Stains

Oil and grease prevent sealers from bonding. Apply a concrete degreaser or a strong alkaline cleaner to any stained areas and scrub with a stiff brush. Leave it to dwell for ten to fifteen minutes, then rinse thoroughly. Stubborn stains may need a second pass. Cat litter or sawdust left overnight to absorb fresh oil before cleaning also helps.

Step 3. Pressure Wash the Entire Slab

Use a pressure washer at around 1,500 to 2,000 psi with a fan tip. Work in consistent passes so you do not miss sections. Keep the nozzle moving to avoid etching a single spot. Remove all algae, moss and dirt completely. On an older slab in shaded areas, you may need a diluted bleach solution to kill biological growth before pressure washing.

Step 4. Repair Cracks and Spalls

Fill hairline cracks with a flexible polyurethane caulk or a concrete crack filler. For spalled (flaking) areas, use a polymer-modified repair mortar. Leave repairs to cure fully before sealing. Skipping this step lets water pool in the crack under the sealer film and worsens the damage over time.

Step 5. Allow the Slab to Dry Completely

This is critical. Most sealers, especially solvents, will blush, peel or turn white if applied to a damp slab. Allow at least 24 to 48 hours of dry weather after washing. In Sydney and Melbourne during autumn, this can mean planning around the forecast carefully. Use a moisture meter if you have access to one. The concrete should read below 5% moisture content.

Step 6. Check the Weather Forecast

Do not apply sealer if rain is expected within 24 hours. Avoid applying in direct sun on a hot day, as the sealer can skin over before it penetrates or levels properly. Early morning on a clear, mild day is ideal. Most sealer manufacturers specify an application temperature range of around 10 to 35 degrees Celsius.

Step 7. Gather Your Equipment

For a standard driveway you will need a long-handled roller with a 10 to 12 mm nap for film-forming sealers, or a pump-up garden sprayer for penetrating sealers. Have a brush handy for edges and around expansion joints. Wear solvent-resistant gloves and eye protection. If using a solvent-based product, wear a respirator rated for organic vapours.

Step 8. Apply the First Coat

Start at the far end and work back toward the street so you do not trap yourself. Apply the sealer evenly in thin coats. Thick application is the most common mistake. It causes solvent entrapment, bubbling and an uneven finish. Two thin coats always outperform one heavy coat.

Step 9. Allow to Cure and Apply the Second Coat

Follow the manufacturer's recoat window, which is typically one to four hours for acrylics. Apply the second coat in the opposite direction to the first. This cross-hatching technique reduces roller marks and gives more even coverage.

Step 10. Keep Traffic Off Until Fully Cured

Foot traffic is usually safe after four to eight hours. Keep vehicles off for at least 24 hours, and ideally 48 to 72 hours for full cure. Parking too early leaves tyre marks in the sealer film that cannot be removed without stripping the whole coat.

Sealing once and forgetting it is not a maintenance plan. The table below gives a practical annual schedule for most Australian driveways.

For decorative finishes such as exposed aggregate or stencilled concrete, the recoat interval is shorter because the UV load on the sealer film is higher and any colour fade is more noticeable. Budget for this in your ongoing home maintenance planning.

Sealing a flat, accessible driveway in good condition is within reach for most capable DIYers. Some situations, though, are better handled by a concreter or professional applicator.

• Large surface area or multiple coats: Getting even coverage on a long double driveway by yourself is physically demanding. Lap marks and missed sections are common on larger slabs without commercial equipment.
• Stripping old sealer: If the existing sealer is peeling, bubbling or has been incorrectly applied, chemical stripping is required before resealing. This involves strong solvents and mechanical grinding in some cases. It is not a beginner job.
• Structural cracks: Cracks wider than about 3 mm, cracks that have moved up or down at the joint (indicating subsidence), or cracks spreading across the slab in a pattern may signal a deeper problem. Fill and seal is not the right fix here. Get a concreter to assess whether subgrade issues or inadequate reinforcement are the cause.
• Polished concrete: Re-polishing and resealing a polished floor requires diamond grinding equipment and specific densifier products. This is always a job for a professional with the right machines.

If you do bring in a professional for sealing work, general market rates for labour and materials vary considerably based on driveway size, surface condition and sealer type. Always get at least two written quotes and ask the contractor to specify which product they are using and how many coats are included. Prices vary significantly by state and access conditions, so a written quote for your specific job is the only reliable figure.