Preparing Your Driveway for Seal Coating

If you have a seal coating planned for your driveway, then the professionals you hired will be able to properly place the sealer across the asphalt. However, if you do not prepare your driveway first, then the material may not last nearly as long as it should. Asphalt sealers can last anywhere from 3 years to 10 years. To make sure the sealer lasts close to 5 or 10 years, consider the preparation tips in this article.

Remove Oil and Gas Stains

Using Cleaners

If you have accidentally spilled gas or motor oil on the surface of your asphalt driveway, then it is likely that these materials have caused stains to appear. Unfortunately, this oil or gas will penetrate the surface of the seal coat when it is applied. Also, the materials will make it difficult for the sealer to stick properly, and this can leave parts of the asphalt surface unprotected. If the oil or gas stain is relatively new, then a cleaning compound may be able to remove it.

Purchase some trisodium phosphate powder from your local home store. Mix two tablespoons of the powder with about one cup of water. Add enough baby powder or talc powder to the mixture to create a paste. Spread the paste on the gas and oil stains. Allow the mixture to sit so it can pull up the stains from the asphalt. As you wait, sweep the rest of the driveway and add three squirts of dish soap to a large bucket of water. Use the soapy mixture and a scrub brush to clean the asphalt.

Once your TSP solution has been allowed to sit for 15 minutes, use a pressure washer to rinse the entire driveway. You should set your pressure washer within the midrange of 2000 to 3000 PSI. A wide-angled, 45-degree tip will work best, too. Place the end of the sprayer about two feet away from the asphalt surface and use sweeping motions to rinse it clean.

Using a Torch

Afterward, inspect the driveway to see if stains are gone. If they are not, then purchase a small butane or propane torch from your local home store. Light the torch and adjust the flame until it is mostly blue in color so it is as hot as possible. Place the flame against each oil or gas stain with the very tip of the flame's cone touching the asphalt. Allow the asphalt to heat up for about 5 minutes. This heating process will help to burn the stains away. Continue heating each stain in 5 minute sessions until the stain disappears or lightens significantly. 

Allow the asphalt to cool and then purchase an oil spot primer. This material is a latex emulsion that creates a barrier over any remaining oil or gas so the asphalt sealer material will stick properly. Use a small roller to place the primer over all areas that have been cleaned and treated with the torch. 

Clear Away Grass

Another thing that you should do before your driveway is sealed it to prepare the edges of the asphalt. Sealers are placed on the asphalt with the assistance of large squeegee-type tools. The tools are not meant for precision, and they can force grass to stick to the edges of your driveway if greenery overhangs over the edges of the asphalt. To prevent this problem, rent and use a lawn edger tool to trim the grass across the edges. Make sure to set the device to a shallow setting so the grass is trimmed but not removed completely. Also, the wheel of the device should be placed directly on the edge of the asphalt. Turn on the edger and move down the right and left side of the driveway to clear the grass away.

Once the grass is trimmed, add a barrier on each edge of the driveway to make sure that sealer does not end up on the grass. Plastic sheeting will work well for this, and you can use small metal stakes every one or two feet along the edge to keep the sheeting in place. Be sure to sweep up the grass clippings from the asphalt.