MAINTENANCE : Sealing, Patching Can Extend the Life of Asphalt Driveways

Regular maintenance can greatly extend the life of your asphalt driveway.

The asphalt commonly used to pave blacktop driveways is more flexible than concrete, but it is vulnerable to the effects of water seepage and temperature change and needs periodic maintenance, repair and sealing.

Blacktop maintenance and repair jobs are best done in warm or, better still, hot weather. Heat makes asphalt more malleable, and helps it to set rapidly and form a better bond.

Always check the manufacturer’s directions before using patching materials and sealers. For cleanup, many sealers are water-washable. Others require mineral spirits. Before each job, be sure to sweep the surface clean of dirt and debris.

Seal Surface Every Few Years

To protect a blacktop driveway, repair hairline cracks or restore its appearance after repair work, treat it with petroleum-based asphalt or coal-tar sealer available at hardware, home or building supply centers. Sealing should be done every two or three years.

Ready-to-pour sealers are sold in five-gallon pails, enough to cover up to 400 square feet of driveway. Pour enough sealer to coat about four square feet. Spread it with a long-handled broom-squeegee, which is available where sealer is sold. Repeat until the entire driveway is sealed. It’s important to stay off the sealed driveway for at least 24 hours.

Some manufacturers recommend applying a second coat of sealer within 48 hours. But check the label directions first, because applying too much sealer can cause the driveway to become overly slick. Some sealers contain sand to provide more traction.

Sealing Cracks

Repair wider cracks, small holes and depressions as soon as they appear; otherwise, water can collect in them and freeze, further damaging your drive.

Seal cracks up to 1/2-inch wide with driveway crack filler sold in caulking-gun cartridges. First, clean out loose debris with a wire brush. If the crack is deeper than 1/4-inch, partially fill it with sand and then apply crack filler from a caulking gun. Use a trowel or putty knife to smooth and level the patch. Don’t overfill the crack.

Repair wider cracks with a sand and sealer mix. In an aluminum pie pan, mix sand and blacktop sealer to a putty-like consistency. Use a trowel to pack the paste into the crack and smooth it flush with the driveway surface. If the paste settles, add more as needed to level the patch.

Repairing More Extensive Damage

Patch small holes, potholes and very wide cracks with cold-mix asphalt patching material.

If the damage is extensive, have a professional repair it with a hot-mix asphalt patch, which must be heated and applied in molten form. Otherwise, use a cold-mix asphalt patching material, which is sold in ready-to-use 60-pound bags at home centers and lumberyards.

* Dig out loose paving to a depth of six inches and remove the debris. Fill the opening with crushed rock and tamp it down with a sledgehammer, 4 by 4 or a rented square-head tamper. Leave enough space for the patching material. Lightly coat the repair area with asphalt sealer.

* Ladle the patching mix into the opening in one-inch layers with a trowel. Tamp each layer down as you did the crushed rock. Prod with the trowel tip to remove any air bubbles. If the patching compacts below the surface, add more and tamp again.

* Sprinkle sand on the patch. Then slowly drive a car back and forth over the patch until it is level with the driveway surface.

* To protect the patch from water damage, coat it with blacktop sealer or seal the entire driveway to avoid a patchwork appearance.