Q: Should I seal my asphalt driveway?
Two different paving contractors told me that it's wrong to apply sealer to my asphalt driveway because the asphalt wouldn't be able to breathe and would break up more quickly than if there were no sealer on it. I've been sealing my drive every few years. What should I do now?
—Roger Peterson, Glastonbury, Conn.
Kevin O'Connor replies: Probably just what you've been doing. "Nobody has done long-term studies of sealer effectiveness," says Kent Hansen, director of engineering at the National Asphalt Pavement Association, "but we believe it prevents driveway surfaces from oxidizing and becoming brittle. It also makes pavement look better." Sealing every year is overkill, he says, but once every three years or so should be adequate.
Sealers are meant for pavement that's in good condition. Before sealing, fill cracks wider than ¼ inch with a "cold-pour" sealant and patch "alligatored" areas covered with many fine cracks with an asphalt mastic, like Gator-Aid. If you don't, Hansen says, "water will get through the pavement and allow it to flex." He adds that some freshly applied asphalt mixes do need to breathe for about two or three months to cure properly. After that, it can be sealed at any time.