Asphalt is also called blacktop. Another term, tarmac, is often used interchangeably, but to be precise, its not the same composition.
Blacktop driveways are not concrete driveways. The same is true of sidewalks and parking lots. Because this is so, they react to the elements in different ways. Eventually it becomes necessary for a asphalt repair job.
The Nature of Blacktop Surfaces
This is basically a petroleum product. More precisely, its a combination of small rock chips, sand, and a kind of asphalt cement. It responds to changes in temperature. It becomes softer in warm weather and becomes harder as the weather cools.
In lockstep with typical physical materials, it will expand and contract with temperature variations.
Most repairs can be carried out by the homeowner. But for anyone that doesnt want to perform the actual labor, I highly recommend Angies List or a similar service. This makes much more sense than going to the yellow pages, closing your eyes, and pointing.
Types of Blacktop Damage
Asphalt is very sensitive to salt damage (just like concrete that is less than about two years old). Because of this fact, its a better move to toss out sand or another non-chemical product for traction safety when ice is on the surface.
Most frequently, there are 2 types of blacktop damage that may occur. First, and and most likely, is surface cracking. This is a normal aspect of the product and theres really nothing on the market that Ive seen that is reliable at preventing it. That said, a sealer applied before trouble develops, will help.
Beware of Expansion and Contraction
Expansion and contraction is usually the culprit, and if its allowed to go unchecked, itll only get worse. Damage in the form of water that fills the crack and ices up in the winter really compounds this problem.
The second type of damage is sunken spots and holes. What will cause this? Usually, its when the builder did a poor job laying the base (foundation) before putting in the parking lot or driveway.
This can cause the support to be sub-standard. When the base is laid properly, it will be 8 to 10 of crushed, well-compacted gravel installed over compacted soil. As always, an ounce of prevention is worth a pound of cure.
How to Repair Asphalt Cracks
Almost everybody has seen municipal road crews fulfilling the new mayors campaign promise (isn't that always their campaign talking point) by patching cracks in asphalt roads. They walk along ladling out heated black goo. Theres an even easier cold patch method for the homeowner. One of the most available products is Quikretes Blacktop Repair (see the photo at the top of this article).
There are other high-quality elastomeric asphalt crack fillers out there. Check the manufacturers recommendations. Some will allow adding sand to very deep cracks.
How to Repair Blacktop Holes
Repairing blacktop surface holes is a bit more difficult than simple cracks. As the first step, all the sunken, broken-up asphalt needs to be excavated. The perimeter edges of the excavation need to be vertical rather than slanted. The edge surfaces function as a retaining wall for the new fill.
How deep does the hole go? If its deeper than 2, finely break up the excavated asphalt material to bring it up to 1.5 to 2 in depth. Then use it as a filler. Conversely, you can use small gravel to raise the depth up to a 1.5 to 2 in depth. Note though, only use sharp edged gravel, never rounded pea gravel.
Finish the Job
Next, tamp down the base solidly. Any instrument that is blunt and wide may be used for this part of the job, even a wooden 4 X 4. Now, fill the hole with the blacktop patching material. Build it up in a convex formation.
It should be about a 1/4 higher than the plane of the driveway surface surrounding it. It's going to settle over time. Finally, butch up and use a steel tamp and a small sledge hammer to compact the patch material, forcing it into the base.
Using a Driveway Sealer
Theres no doubt about it, an asphalt driveway needs be sealed for protection. But dont jump the gun. Do not apply a sealer to a new surface or a patch for a minimum of 30 days. The material needs open-air curing as the hydrocarbons evaporate.
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About the Author:
Kelly R. Smith was a commercial carpenter for 20 years before returning to night school at the University of Houston where he earned a Bachelors Degree in Computer Science. After working at NASA for a few years, he went on to develop software for the transportation and financial and energy trading industries. He has been writing, in one capacity or another, since he could hold a pencil. As a freelance writer now, he specializes in producing articles and blog content for a variety of clients. His personal blog is at I Can Fix Up My Home Blog where he muses on many different topics.