There are many benefits to seal coating an asphalt driveway or parking lot. Along with the obvious improvement in appearance that a new, clean surface provides, it protects the asphalt from deterioration.
One of the benefits provided by a new layer of coating is ease of maintenance. Most grime will wash away when it rains. This keeps your driveway looking clean even if you don't go out and scrub it down. During dry spells, just hit it with a hose for the same cleaning effect.
Sealcoating also hides patches, rough areas, small cracks and stains in the underlying asphalt. This makes the driveway or parking lot look much better than it otherwise would. Parking lines and other traffic paint will also stand out more. This is a great benefit for parking lots and commercial driveways.
Coating asphalt protects it from UV rays. The sun's rays normally will increase asphalt's porosity and make it more susceptible to staining and other damage from things like oil and gas spills. By coating it, you help it resist this damage and extend its life.
Finally, coated asphalt is much more water resistant than it otherwise would be. This is very important in climates with a cold winter. Uncoated asphalt can absorb water, which will then freeze and cause cracks when winter comes.
Repairing asphalt can be very expensive. The high price comes from the combination of labor and the cost of the material itself. Asphalt prices change with the cost of oil, so the cost of repairs rise in tandem with oil's march to ever-higher price levels. It is much cheaper to coat a driveway and prevent damage from ever occurring than it is to ignore your driveway and have to fix it later.
Once you've decided to sealcoat your driveway or parking lot, you will need to determine whether you want to do the job yourself or hire a service. Doing the job yourself is cheaper but requires some work. Here is a quick overview of what it takes to do it yourself.
First, the pavement will need to be cleaned. This begins with simple sweeping. You will also need to dig any loose asphalt, gravel or other debris out of the surface. Power washing is likely the easiest way to dislodge the particles. You will also need to cut down any weeds that are growing over or through the surface.
If you used a cleaning method other than power washing, you will now need to scrub the surface with a driveway cleaning solution. This will allow the coating to adhere to the asphalt.
If there are any cracks or potholes, you need to fix them before coating the driveway. Narrow cracks can be filled with semi-liquid filler, while larger ones will need asphalt cold patch. Cold patch is a grainy substance sold in cans or bags.
Potholes will need to be prepared before repair. This generally involves smoothing them out and undercutting the edges to provide a good anchor point for the filler material. Filler can be hot or cold. Most hardware-store fillers will work fine for the light load of a residential driveway.
Actually sealing the asphalt is next. Mix the coating according to the instructions on the package. Then apply it with a rented sprayer or use a pole-mounted trowel to spread it evenly over the surface. Make sure you choose a dry day with no rain predicted so that the coating will have a chance to properly cure.
Of course, there is a much easier way to get seal coating onto your driveway or parking lot: contact a qualified service and watch them do all of this work for you. When they're done, write the check and enjoy looking at the perfect results.