Dear James: I was told not to reseal our new asphalt driveway for several years. After three years now, it looks a bit worn. Is it time to seal it, and what is the best sealer and method to apply to it? -- Juan T.
Dear Juan: You are probably about 2 1/2 years late for the first sealing of your driveway. Although it will probably be fine, you really should have sealed it within the first six months for the longest life and best long-term appearance.
It normally takes about three to six months for light oils and other volatile chemicals to evaporate from a new asphalt driveway. It should not be sealed during this time so as to allow these chemicals to escape from the surface as it solidifies.
After this initial period, the surface should be sealed to protect it from such things as gasoline, engine oil, dirt and the sun. When it gets hot in the sun, these things can cause the surface to begin to oxidize and rob it of its natural oils. This, along with the sun's damaging ultraviolet rays, make the asphalt become brittle and discolored.
An asphalt driveway is a mixture of sand, gravel and asphalt material. The gravel and sand provide the strength for the driveway to support the weight of cars. The asphalt itself is just the glue that holds the sand and gravel together. It is a similar concept to concrete, which uses cement to hold sand and gravel together for strength.
There are several types of sealers available, and their quality and prices vary. You can probably buy some inexpensive sealer on sale at most hardware and home center stores. It is basically just liquid asphalt, which you spread over the driveway. It typically has a life of about two to three years.
The next step up in quality is the same basic type of sealer with additional additives that are more resistant to petroleum chemicals and the sun. Coal tars, sand and clay are common additives. If your driveway is hilly, the sand and clay will improve the traction in rainy weather.
Acrylic-based sealer is probably the best product to use. It can cost as much as double the price of basic sealer, but overall, it is less expensive because it can last up to eight years. It looks good when applied and maintains its good appearance. It is often used on tennis courts.
It is not difficult to apply sealer, but it is messy. Wear old sneakers and plan on discarding them when you are done. The key to an effective job, as with painting, is cleaning the surface thoroughly. Sweep away the large debris, and then spray it off with a hose. If you have a pressure washer, using it will deep clean the driveway. Use a special driveway cleaner on any spots of oil that still appear shiny.
Use an asphalt patching compound in any indentations where you see standing water. Compress it as much as possible. Tamping it with a four-by-four wood post works well. Fill any wide cracks with several coats of asphalt crack sealer. It comes in a large jug with an application tip. When the surface is ready, wet it slightly and spread the sealer over the driveway with a stiff broom or sealer squeegee.
James Dulley's weekly column, "Here's How," can be found at creators.com.