Repairing and Resealing Your Asphalt Driveway
Many of us don't even think about it, but driveways, just like everything else around the house, do need to be maintained. In the U.S., asphalt is far and away the most common material for driveways, and if you spend any time driving on a highway, you'll quickly see asphalt needs maintenance - and so does your driveway.
An unmaintained driveway will develop cracks, allowing water to get in under the asphalt. If you live in a cold climate where water will freeze in the winter, the expansion and contraction will cause heaves in the surface, make bigger cracks and eventually destroy the driveway. Even if you live in a warmer climate where the water won't freeze, if it gets under the drive, the ground will expand and contract with the changes in water content, causing cracks.
So if you are starting to see some small cracks in your asphalt driveway, or it's starting to look a little gray (rather than that nice shiny black color), you need to do some driveway maintenance.
Resealing Your Driveway
Resealing your driveway isn't a difficult job, and everything you need to do the job is readily available at local home stores. However, it's a messy job, and needs to be done over a couple of days when there is no rain in the forecast.
Your first step is to clean your driveway. Sweep or power wash any grit off the surface, and then wash it with a product like TSP (Tri Sodium Phosphate) or specialized asphalt cleaner. These will remove any oil spills or stains on the driveway. Since asphalt is a petroleum-based product, the oil spills will break down the driveway surface, create soft spots and allow water to seep through.
Fill any surface cracks with filler. Driveway crack filler is available in a couple of textures: a pourable liquid with a consistency similar to ketchup, or a much more solid product that comes in a tube and is applied with a caulking gun. Before using the crack filler, try to widen out the base of any cracks (undercut them), so the crack is wider on the bottom than at the surface. This will help to keep the filler anchored. Overfill the crack and then smooth the surface with a trowel or even a piece of wood. If you have deep cracks, fill them to about 1/2" of the surface with sand or "backer rod" (a crack filler that resists moisture), then apply your crack filler.
Any dips or holes in your driveway can be smoothed out or filled in with cold patch (asphalt pre mixed with small aggregate). Scoop the patching compound into the depression, pack it tightly with the end of a 2x4 or a 4x4 and let it set up overnight.
The final step is actually sealing the surface. You'll need to do this on a day with no rain in the forecast so the sealer can dry thoroughly. Apply the sealer with a combination brush/squeegee, or a long handled paint roller and a long nap roller sleeve. Sealing the driveway is essentially the same as painting it, but since different types of sealers are available, be sure to read and follow the manufacturer's directions on the product.
Once the sealer has dried, your driveway will once again have its shiny black appearance, but even more important, it will be protected from any little oil spills and there will be no cracks to let water get under the drive.
A word of caution: Products used for driveway repair are very messy to work with. Any spills or splashes can usually be removed with a Varsol like product if you clean them before they dry thoroughly. Even more important, be sure you don't track any into the house on your clothes or shoes.