Guides / Driving on New Concrete
As a general rule, you can walk on a new concrete slab after about 24 hours and drive a car on it after about 7 days, and you should wait longer in a cold Bendigo winter. Those are safe rules of thumb, but the real number depends on the mix, the thickness and the weather on the day, so always go by the time your concreter gives you.
The temptation to get the car back on a new driveway is strong, especially when it looks hard within a day. It is not as hard as it looks. Here is what is actually happening in the slab, and why Bendigo's climate pushes the timing at both ends of the year.
Concrete does not dry, it cures. It gains strength through a chemical reaction between the cement and water that keeps going for weeks, fastest in the first few days and then tapering off. A slab reaches roughly 70 percent of its strength in the first week and keeps climbing toward full strength over about a month.
That gives the standard timeline. Foot traffic is fine after about 24 hours, once the surface is hard enough not to mark. A car or light vehicle is safe after about 7 days, once the slab has enough strength to take the load without cracking or leaving tyre indentations. Heavy vehicles, a loaded trailer, a caravan or a concrete truck should wait longer again, ideally the full 28 days or on your concreter's advice. Those are the numbers on a normal week. Bendigo's weather regularly gives you anything but a normal week.
Bendigo swings hard between hot dry summers and cold frosty winters, and both ends affect a fresh slab.
Winter frost slows it right down. The curing reaction slows as the temperature drops, and Bendigo winters bring overnight frosts and sub-zero nights from around May to August. A slab poured in the cold gains strength more slowly, so the seven-day rule stretches out and you keep vehicles off for longer. Fresh concrete also must not be allowed to freeze, because ice forming in the slab damages it permanently, so a concreter will not pour into a frost and will protect a new pour from freezing overnight. A winter driveway simply needs more patience.
Summer heat speeds the set, but that is a risk not a shortcut. On a 40°C-plus Bendigo day the set speeds up, but the heat also pulls moisture out of the slab fast, which can cause plastic shrinkage cracking and a weaker surface. That is why summer pours are started early in the morning to beat the heat and then actively cured to hold the moisture in. The slab may feel hard quickly, but you should still follow your concreter's timing rather than reading the surface and rushing the car on. Getting the pour and cure right in the heat is covered in the best time to pour guide.
Most of the work is your concreter's, but a few things help. Keep vehicles and heavy loads off until you are told it is safe. Keep sharp turns off a new driveway for the first few weeks, because a car wheel turned on the spot scuffs and stresses a young surface. If your concreter has covered the slab or asked you to keep it damp in hot weather, leave it be, that is the curing being managed. And do not park a trailer or skip on the edge of a new slab early, because edges are the last part to gain strength.
All of this assumes the slab was built properly in the first place. Correct thickness, steel on chairs and control joints are what let a driveway take a load on schedule, and they are set long before the pour. See concrete driveways in Bendigo for how that is done, and if you are having an old slab overlaid, resurfacing has its own curing time before you drive on it too.
Planning a new driveway and want to know how the timing will fall around your plans? Tell us your suburb and roughly what you need and we will get a local concreter out to quote it and talk you through the curing time for the season. It is free and there is no obligation. Call 0482 392 415 or use the contact page.
As a general rule, you can walk on a new slab after about 24 hours and drive a car on it after about 7 days. In cold Bendigo winters strength gain slows, so keep vehicles off longer, and your concreter will give you a firm number based on the mix, the thickness and the weather.
Concrete gains strength through a chemical reaction that slows right down as the temperature drops. Bendigo winters bring overnight frosts and sub-zero nights, so a fresh slab hardens more slowly and needs longer before it takes a load. Fresh concrete must also not be allowed to freeze, so a concreter will not pour into a frost and will protect a new slab from freezing.
Concrete does set faster in the heat, but a 40 degree Bendigo day is a risk, not a shortcut. Heat pulls moisture out of the slab too fast, which can cause plastic shrinkage cracking and weaken the surface. That is why summer slabs are poured early in the morning and actively cured, and you should still follow your concreter's timing rather than rushing on.
You can crack it, leave tyre indentations or break the edges, and that damage is permanent. Driving on a slab before it has gained enough strength is one of the few ways a homeowner can genuinely ruin an otherwise good driveway. When in doubt, wait the extra day or two, especially after a cold pour.
Get a free, no-obligation quote from a concreter who works your part of Bendigo.