Repairing a driveway is a matter of time and good technique
By Tim Carter,
My asphalt/blacktop driveway is starting to crack in several places. It looks like holes and entire sections of the blacktop will fail. I can’t afford to have a professional come in to repair the drive. I’ve installed patches in the past, but they all failed and popped out. Is there a way to patch my driveway and have the repairs last for many years? What did I do wrong?
— Amy S., Goochland, Va.
It’s possible to repair your driveway yourself, but it may take some extra effort on your part to get long-lasting results. The job will go a lot quicker if you have access to a power demolition hammer from a tool rental center.
Potholes in driveways and roadways appear like mushrooms after a spring rain, often with little warning. Unfortunately, even after they are fixed, many potholes reappear again because the repair was done poorly or because one or two very important steps were skipped.
Most blacktop or asphalt hole repairs fail for one of two reasons: The shape of the hole is wrong, or the base material under the blacktop is either fouled or not compacted. If you want to patch the hole in your driveway only one time, you have to do several things correctly.
It sounds as if you’ll have to remove some of the cracked blacktop to make the repair. It’s possible that past repairs failed because you tried to add patching compound on a shallow depression. That method will never work if you’re using the ready-mixed asphalt repair products that come in a bag.
Think about how fillings in teeth work. Your dentist drills into your tooth and creates a hole where the bottom of the hole is slightly larger than the top. He adds a filling compound that gets hard quite quickly. Because of the shape of the hole, the filling is locked in place. You need to do the same thing with your pothole.
I’d use a power demolition hammer with a 1.5-inch-wide flat chisel at the end to excavate the failing blacktop in the center of the cracked area. When you’re at the edges of the cracked area, be sure you lean the top of the power hammer in toward the center of the hole. This will create an angled face on the edges of the blacktop. Remove all loose pieces of blacktop from the hole so the gravel base is exposed.
Make sure the crushed gravel under the blacktop is free of any mud or soil. If there is mud in it, removed the fouled gravel and replace it with crushed gravel that matches what was originally under the blacktop. Compact it well with a tamping tool or a flat piece of wood you hit with a hammer. You can add a small amount of water to the gravel to help compact it.
Read the instructions on the bag of blacktop repair material. They will tell you the minimum and maximum thickness of the repair patch. Usually you can safely add three inches of patch material, but you must do it in several stages. You add one inch of material to the hole and then compact it.
Your final layer of patching material needs to be slightly less than one-half inch above the surrounding blacktop. Using a heavy metal tamper, you want to pound the repair material so it’s flush with the surrounding blacktop. Be sure not to leave a shallow depression that will cause a puddle to form after a rain.
Tim Carter is a columnist for Tribune Media Services. He can be contacted through his Web site at www.askthebuilder.com.