There are two reasons to plan a DIY recoating of your concrete driveway: you need to recoat your concrete sealer, or you need to repair a damaged driveway. Heavy rains during set-up and freezing temperatures may crack your driveway so badly that recoating is the only choice. The more common need to recoat is much more favourable. Concrete sealers last three to five years; your driveway needs periodic recoating to keep from cracking due to weather, use or stress.
Recoat or Repair
When making improvements to your concrete driveway, you want to save time and money. The best way to minimise labour efforts is to make sure you're only recoating your driveway when you really need to. If your concrete driveway is cracked, you can repair the cracks without recoating the driveway. Ace Hardware suggests repairing cracked concrete with a mixture of sand, Portland cement and gravel. Mix one part cement, two parts sand and three parts gravel with enough water to moisten the mixture, then fill cracks with this paste. Cover the patched area with cling film and moisten with a hose once a day for five days.
If you just laid a concrete driveway and your driveway got rained on as it was setting, it will be cosmetically and structurally damaged. In this case, the American Concrete Pavement Association recommends sanding away the damaged layers with a diamond grinder. Once you've removed the damaged parts, you can recoat the driveway with a fast-drying concrete.
Old concrete driveways may need to be recoated with sealant every three to five years. This is the most common type of recoating you will need to do with your concrete driveway.
Before gathering supplies for your recoating job, choose a sealer. Sealers are available in an array of styles, allowing you to personalise your driveway with a splash of colour. Colour isn't the only choice you'll need to make. Concrete sealer can be applied via spray gun, paint roller, mop or metal straight edge. Spraying and rolling are the two most common methods. If using these, you will need either a spray gun or a paint roller and tray.
Before you recoat your driveway's sealer, clean the surface by sweeping it with a long-handled broom. Wash down your driveway with a power washer or soap and water to remove any dirt or grime. You don't want to seal the dirt into the concrete. Apply the sealer and wait for it to dry before using the driveway. Sealers protect your concrete driveway from oil or gas stains, weather-related cracking and UV rays.
Recoating with Concrete
If you need to recoat your driveway with concrete, self-levelling concrete is easy to apply and takes less time to dry and cure than standard concrete. Self-levelling concrete corrects localised problems in your concrete driveway and can be used to top rained-on concrete, frozen concrete or uneven concrete. To recoat with self-levelling concrete, mix the concete following the manufacturer's instructions. Pour the concrete over your driveway and, working quickly, spread it with a shovel, broom or screed. Once the area is covered, level the concrete by dragging a wooden plank over the surface; then brush it with a long-handled broom to create traction marks. Unless you are working on a very windy or dry day, the self-levelling concrete should be left alone to cure. Spray down the self-levelling concrete periodically with water in high wind or dry conditions for one to three hours, then allow it to dry naturally.