Tim Carter, a nationally syndicated columnist who writes about home improvement, contends that sealing a concrete driveway extends its life by protecting it from the elements. If you've installed a decorative concrete driveway---one made from dyed or stamped concrete---applying a sealant will also enhance the driveway's appearance.
How often you need to seal your concrete driveway depends on the quality of the sealer you use. "Depending on the type of sealer used and exposure conditions, a sealer may last anywhere from 1 to 3 years," according to the Concrete Network.
Know Your Acrylics
Acrylic-resin based sealers are the most commonly sold, but the best acrylic is virgin or pure acrylic resin, which lasts longer and won't yellow, according to the Concrete Network. Carter, on the other hand, recommends silane-siloxane sealers.
Neither virgin nor pure acrylic resin sealers or those based on silane-siloxane will turn yellow over time, but equally important, they breathe, permitting moisture and air to escape from the concrete. This action prevents fogging or hazing between the concrete driveway and the sealer. Carter strongly suggests that you buy a sealer clearly marked "breathable" on the label.
Furthermore, you should not seal a driveway, or any exterior concrete surface, with a sealer containing epoxies and polyurethanes. Besides causing fogging, these additives make the sealed surface slicker, which could be dangerous.
Generally speaking, you get what you pay for in a sealer. "Lower-cost sealers bought at your local hardware store usually can't match the quality and performance of commercial professional-grade sealers bought at a concrete materials supply house," according to the Concrete Network.
Shopping for Sealer
Read the label on the sealer can and ask to see the technical data sheet. Look for a product that breathes, does not yellow, is water- and dust-proof and resists acids, oil and grease. Make sure the instructions for applying the sealer are detailed and clear.
Talk to the salespeople about which sealers sell the best and which get good reviews from customers. The time you invest in research can make the difference between sealing your driveway every year or sealing it once every three years or so.