Sealing a new-build driveway on the Central Coast.

No, your builder did not seal it.

This is the single biggest misunderstanding we deal with in the new estates at Warnervale, Wadalba, Hamlyn Terrace and Woongarrah. What most new-build driveways get is a curing compound, sprayed on the day of the pour to hold moisture in while the concrete hydrates. It is not a sealer. It is temporary, it is designed to break down, and it is gone within months. Owners see the sheen at handover, assume they are protected, and then wonder why the driveway is staining a year later.

Test it yourself: tip a cup of water on it. If it beads, something is working. If it soaks in and leaves a dark patch, you were never sealed. On the new-build driveways we test, it soaks in almost every time.

The 28-day rule.

Wait a minimum of 28 days from the pour, and we prefer longer for exposed aggregate and decorative finishes. Concrete needs that time to hydrate and to let its own moisture out. Seal it early and you trap that moisture under the coat, which turns a topical sealer cloudy and can stop a penetrating sealer soaking in properly. Twenty-eight days is the number your slab needs, not a number we invented to slow you down.

So there is a window, and it is the whole point of this page. Too early and the coat fails. Too late and the slab has already drunk its first year of oil drips, brickie’s mortar wash, paint splashes and leaf tannin. The sweet spot on a Central Coast new build is roughly one to three months after the pour, weather allowing, which our seasonal guide will help you place.

The white bloom is not salt.

New slabs very often come up with white patches in the first few months and people panic, because they have heard about salt damage on this coast. It is almost always efflorescence, which is a completely different thing. Free lime inside the fresh concrete migrates to the surface with moisture and leaves a white powdery bloom. It is normal on new slabs, it is cosmetic, and it usually stops on its own.

The mistake is sealing over it. We wash it off with an efflorescence remover, let the slab dry properly and then seal, otherwise it gets locked under the coat where nobody can reach it and you look at it for five years. Genuine chloride scaling looks and behaves differently and takes years to develop, which is covered on our salt scaling repair page.

New aggregate is thirstier than you think.

Exposed aggregate is what most new Central Coast homes get, and it is the most vulnerable surface on the block. It is deliberately porous, the cement matrix between the stones is exposed by design, and it will absorb a stain in hours. The first year of a new house is also the worst year for spills: trade utes dripping oil, mortar wash off the brickwork, paint from the fit-out, render splatter, and the landscaper’s soil bags leaching straight into the stones. We have sealed a lot of two-year-old aggregate driveways where the permanent marks all date from the six weeks before handover.

Sealed early, aggregate looks the way it did in the display home for years. Left bare, it goes pale and dusty and starts dropping stones by year five. The detail is on our exposed aggregate sealing page.

New estates have no shade, and that matters.

A new estate is a treeless estate. Full unbroken UV all day is hard on a topical sealer, so on the newer northern estates around Wyong we push people toward UV-stable products and penetrating chemistry rather than the cheap solvent acrylics. The flip side is that new estates have almost no tannin problem for the first decade, so if you are inland and out of the salt, your driveway is genuinely in the easiest position on the Coast. Down near the water at Terrigal or Avoca, salt is on the slab from week one regardless of how new the house is.

Prep is a first-year problem.

Before we seal a new slab we look for the things the trades left: mortar and render splashes, paint drips, the concrete pump washout patch, and the tyre marks from a truck that turned on green concrete. Those come off far more easily at three months than at three years. There is one more thing worth knowing: many new slabs carry laitance, a thin weak film of fines on the surface. It needs to come off or a sealer bonds to something that is not really concrete. That is part of a proper prep, and it is one more reason the cheap quote is cheap.

Warranty: sealing does not affect it.

Sealing is normal owner maintenance, not an alteration. Under the NSW Home Building Act 1989 your statutory warranties run for six years on major defects and two years on other defects from completion, and applying a sealer does not affect them. If the slab itself is defective, cracked, unevenly finished or badly discoloured, that is a warranty conversation with your builder, not something a sealer should be used to hide. We will tell you if we think that is what we are looking at, and we would rather you got it fixed properly by the people who owe it to you than pay us to gloss over it. We are not building consultants and we will not write you a defects report, but we know a bad finish when we walk on one.

What it costs.

A new slab is the cheapest driveway we will ever seal, because there is no oil, no moss and no twenty years of staining to prepare, so the prep component is minimal. Exposed aggregate is $14 to $26 per square metre, plain concrete is $6 to $11, and pressure clean and degrease at $3 to $7 is included in the quote rather than added later.

Worked example. A new home at Hamlyn Terrace, 45m² of exposed aggregate, poured ten weeks ago, efflorescence across the top third and two small oil drips from the fit-out trades. The job is an efflorescence wash, spot degreasing, full dry-out and two coats of a UV-stable wet-look sealer: roughly $650 to $1,150, one day on site plus cure. The same driveway sealed for the first time at year six, once it is pale, dusty and dropping stones, needs stone re-fixing and heavier prep first and lands closer to $1,200 to $1,800, assuming it has not gone far enough to need resurfacing. Full rates are on the pricing page and every surface is broken down on our cost guide.

The honest advice.

If you have just moved into a new build on the Coast, put a reminder in your phone for four weeks after the pour date and get it looked at then. It is the cheapest, easiest driveway job that exists, and it is the one time you are protecting a perfect surface instead of trying to rescue a compromised one. If your slab is only two weeks old, we will tell you to wait, and we will not take the booking.

New-build questions.

How long should I wait before sealing a new concrete driveway?

A minimum of 28 days from the pour, and we prefer longer for exposed aggregate and decorative finishes. Concrete needs that time to hydrate and to let its own moisture out. Seal it early and you trap that moisture under the coat, which turns a topical sealer cloudy and can stop a penetrating sealer soaking in properly. Twenty-eight days is the number your slab needs, not a number we invented to slow you down.

Did my builder already seal the driveway?

Almost certainly not. What most new-build driveways get is a curing compound, which is sprayed on the day of the pour to hold moisture in while the concrete hydrates. It is not a sealer, it is temporary and it is designed to break down. Owners see the sheen at handover and assume they are protected, then wonder why the driveway is staining a year later. Tip a cup of water on it: if it soaks in, you were never sealed.

Why does my new exposed aggregate driveway have white patches?

That is efflorescence, not salt damage. Free lime inside the fresh concrete migrates to the surface with moisture and leaves a white powdery bloom over the first few months. It is normal on new slabs, it is cosmetic, and it usually stops on its own. The mistake is sealing over it. We wash it off with an efflorescence remover, let the slab dry properly and then seal, otherwise it gets locked under the coat where nobody can reach it.

Does sealing a new driveway affect my builder’s warranty?

No. Sealing is normal owner maintenance, not an alteration. Under the NSW Home Building Act 1989 your statutory warranties run for six years on major defects and two years on other defects from completion, and applying a sealer does not affect them. If the slab itself is defective, cracked, unevenly finished or badly discoloured, that is a warranty conversation with your builder, not something a sealer should be used to hide. We will tell you if we think that is what we are looking at.

What does it cost to seal a new-build driveway on the Central Coast?

Exposed aggregate, which is what most new Central Coast homes get, is $14 to $26 per square metre, so a typical 45 square metre new-estate driveway is roughly $630 to $1,170. Plain concrete is $6 to $11 per square metre. A new slab is the cheapest driveway we will ever seal, because there is no oil, no moss and no twenty years of staining to prepare, so the prep component is minimal.