Sydney Concrete Questions, Answered Plainly

Before the job

How thick should a concrete driveway be?

Residential driveways for cars are commonly poured thicker than paths and with reinforcement, and driveways carrying heavier vehicles need more. The right figure depends on the vehicles, the ground and any engineering requirements, so it should be written on your quote rather than assumed. Commercial driveways are designed from the loads. See commercial concrete driveways.

What strength of concrete should be used?

Concrete in Australia is ordered by strength, measured in megapascals (MPa) at 28 days. Residential driveways, slabs and paths use standard strengths, and structural or commercial work follows the engineer's specification. The quote should name the strength.

Do I need council approval?

It depends on the job:

• Driveway crossings over the footpath and kerb are on council land, and most Sydney councils require an application first.
• Retaining walls above certain heights, near boundaries or supporting structures usually need approval and engineering.
• Slabs for garages, carports and larger sheds often form part of a development approval or complying development certificate.
• Minor paving and paths can sometimes be exempt development under the NSW planning rules if they meet set conditions.

Check with your council or a certifier before work starts. Information on this site is general, not approval advice.

What about pipes and cables underground?

Request plans through Before You Dig Australia before excavation, and point out your own private pipes, drainage and cables to the concreter. If you plan to build near a Sydney Water sewer main, Sydney Water's requirements for building over or near its pipes may apply.

During the job

How long does a concrete job take?

A simple path or slab might be prepared and poured in a couple of days. A full driveway replacement, including demolition, base, formwork, steel and pour, often takes several days, plus curing time before cars use it. Larger and staged jobs take longer.

Why is my driveway being cut so soon after the pour?

Control joints are cut once the concrete is hard enough not to ravel but before it cracks on its own. That can be within hours on a hot day. See concrete saw cutting.

Should I water the new concrete?

Your concreter will tell you how they want it cured. Keeping new concrete moist, or covered, helps it gain strength and reduces surface cracking, especially in hot or windy weather.

Can concrete be poured in winter?

Yes. Sydney winters are mild enough for concreting year round. Cooler weather slows setting and curing, so finishing takes longer and joints may be cut later in the day. Frost is rarely a problem in most of Sydney, but cold mornings in the outer west can slow things down. Wet weather is the bigger cause of delays.

After the job

When can I walk and drive on it?

Usually walking within a day or two and cars after about a week, but this depends on the mix, the weather and the job. Heavy vehicles wait longer. Your quote should give the dates.

Is cracking normal?

Some fine cracking is normal, because concrete shrinks as it dries. Joints are there so most of it happens neatly along the cuts. Wide cracks, cracks with one side higher, or cracks that keep growing suggest movement underneath and are worth having looked at.

Should concrete be sealed?

Decorative finishes such as exposed aggregate, coloured and honed concrete are often sealed to resist staining and make cleaning easier. Plain broom-finished driveways often are not. Sealers wear and need reapplying.

How do I clean oil stains?

Fresh oil is easier to lift than old stains. Absorbent material and a suitable concrete cleaner usually help. Sealed surfaces resist stains better. Test any product on a small area first.

About this service

Are you a concrete company?

We are a referral service for concrete work in Sydney. When you call or send the form, your enquiry goes to an independent local concreter who quotes and does the job. The arrangement is set out on our disclaimer page.

What does it cost to use this service?

Nothing extra. Quotes are free, and you deal with the concreter for the job.

For prices, see the Sydney concrete price guide. For finishes, see our driveway finish comparison.