Extend Life of Blacktop Driveway

Your blacktop or asphalt driveway will last for years if you maintain it regularly.

Asphalt commonly used to pave driveways is the same as that used for roads and walks. It’s a type of concrete in which graded aggregate, such as small stones or gravel, is held together by an extract of crude petroleum rather than cement.

Asphalt is more flexible than concrete made with cement, but it’s more vulnerable to the effects of water seepage and frost and needs periodic maintenance and repair.

Protect your blacktop driveway from cracks and stains by sealing it. Use an emulsified asphalt or coal-tar sealer available at hardware, home or building supply stores. Sealing should be done every two or three years--or annually, if the driveway gets a lot of wear. Sealing will also restore the appearance of the drive after repair work.

Check the weather forecast beforehand. There should be at least two days of dry, warm weather following the completion of the sealing. A sudden rain may wash the wet sealer away.

Blacktop maintenance and repair is best done in warm weather (over 60 degrees Fahrenheit) when asphalt materials are more malleable and when the materials set more rapidly.

Ready-to-pour sealers come in 5-gallon pails, usually enough to coat 300- to 400-square-feet of driveway. Some manufacturers recommend applying a second coat of sealer in 24 hours. But check the package directions first; applying too much sealer can cause the driveway to become overly slick.

Sealing a blacktop driveway takes care of hairline cracks. Repair wider cracks and depressions before applying sealer. If possible, fix defects as soon as they appear. Otherwise, water collects, and they widen and enlarge.

To repair cracks up to one-half-inch wide, first clean out loose debris with a wire brush. If the crack is more than one-quarter-inch deep, partially fill it with sand. Apply crack filler, which is sold in cartridges to fit in a caulking gun. Don’t fill the crack to overflowing. Use a trowel or putty knife to smooth and level the patch.

To fill wider cracks, first clean them out. In an aluminum pie-pan, mix sand and blacktop sealer to a puttylike 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 to level the patch.

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Larger holes call for cold-mix asphalt patching compound. It’s a good idea to buy a bit more than you think you’ll need. The material should be loose in the bag. If it’s lumpy, store it in a warm place for several hours or overnight.

To fill a large hole, clean out the debris and fill any larger void in the subsurface with crushed stone, tamping down the stone with a sledgehammer or a length of 4-by-4. Ladle the patching mixture into the hole in 1-inch layers. Use a 4-by-4 to tamp down one layer before adding the next. Overfill the hole. Then sprinkle sand on the patch and slowly drive your car over the patch until it’s level with the driveway.

If the damage is extensive, have a professional repair it.

To seal your driveway, sweep away debris. Pour sealer to coat 4 square feet. Spread it with a long-handle broom squeegee. Repeat until the entire driveway is sealed; stay off it for 24 hours.

For cleanup, many sealers are water-washable before the sealer dries. Others require mineral spirits.