Seal an asphalt driveway once every two to three years; sealing the driveway more often may lead to hairline cracks and peeling. When sealed properly, an asphalt driveway has a fresh, black finish and is better protected from oil damage and cracks.
Asphalt sealer is available in 5-gallon drums that range in price from $8 to $20 as of 2015. One drum typically covers approximately 100 square feet. Manufacturers suggest using two thin layers instead of one thick coat of sealant.
Always wear gloves, eye protection and a breathing mask while sealing a driveway. Sealing asphalt driveways can be a messy job, so wear clothes appropriate to the task.