Over the years, our 45-foot-long driveway has acquired its share of cracks. They have always been attended to one way or another, so the driveway is still flat and very usable. The problem is that the cracks have widened to the point where some now are approximately 1/8- to 1-inch wide. We have tried various patching compounds which have worked with varying degrees of success, some lasting for a few years, while others lasting only weeks!

We absolutely cannot afford to replace this driveway, and I can be pretty handy around the house, but I'm just not sure which product would give the longest life. (I'm aware that nothing will last permanently.) I have seen driveways that look like they have been filled with a sticky looking black substance, but am unable to find out what that product could be. Please help! I know from driving around town that many people would love the best solution possible without taking out a loan to buy a new driveway! Thank you for your consideration.

One thing you didn't mention in your letter is whether or not your driveway has any expansion (or control) joints. Expansion joints, which should be placed every 10 to 15 feet, allow concrete to expand or contract with temperature changes—repeated expansion and contraction often result in cracks. Generally, if a crack hits an expansion joint, it will not continue into the section of concrete on the other side of the joint. However, I should point out that driveways often crack even with properly placed expansion joints. Because of nature and variables in concrete materials, many concrete contractors will not warrant their driveways against aesthetic cracking.

In your case, when you described the driveway as "flat and very usable," I assumed that no settling has occurred and the grade is virtually flat. If so, then expansion joints can still be cut in with a concrete saw using a diamond blade, existing cracks can be repaired, and a thin topcoat of polymer modified cementitious coating can be applied to make the driveway look new again.

A mechanical fix can be made at the cracks by undercutting the crack with a cold chisel and hammer to provide holding power to the new patch. Safety goggles will be required for this approach. Deep and wide cracks could be lined with a combination of epoxy and woven fiber and then filled with an acrylic modified grout. Smaller cracks could be packed with a soft or closed cell backer-rod followed by a gray- or limestone-colored elastomeric self-leveling polyurethane sealant such as SL 1 by Sonneborn. This product may be available in your area or you may need to conduct an Internet search to find it.

If it were my driveway, I would have a professional cut in the expansion joints and fix the cracks. Look for a professional who has experience in making concrete look new without replacing it. This can be accomplished by doing some prep work: acid washing followed by power washing and finally predamping the surface to accept a polymer modified cementitious surface coating by Tamms (www.tamms.com). An experienced professional should handle this type of project.

The driveways you describe that look like they have been filled with a sticky-looking black substance most likely were patched with a hot-poured or cold-applied asphalt filler/sealer. It could also be a product called Pli-Stix rope (www.daltonenterprises.com/pr-plistix.html) by Dalton Enterprises. This unique hot rubberized crack and joint sealant is designed for use by homeowners to fill cracks in asphalt (not concrete) driveways or to fill a joint between the asphalt driveway and concrete garage floor.

The rope-like joint sealant is fitted into the crack and heated with a torch to melt. For contractors who need a larger pack size, they offer Crack Stixs (www.daltonenterprises.com/pr-crkstix.html).

For those who have cracked driveways, I encourage you to take time to assess the situation and not to get impatient to correct the problem. You could only make it worse. I personally would rather live with open cracks in concrete than to put black asphalt filler into them. Hopefully the suggestions here will provide you with some ideas to research.

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C.R.S., Inc. · Spokane, Washington · USA