One of the benefits of asphalt paving is that it can easily be repaired if it develops a pothole or a large crack — this isn't always possible with concrete. Yet, not all patches are created equal, so it's important to understand the process.
Challenges In Asphalt Patching
The main challenge when it comes to patching asphalt successfully is to get to the crack or hole before it becomes overly large. For this reason, it is best to patch as soon as the damage is noticed. Damage ignored can widen and deepen to the point that it reaches the base below the paving. Once this occurs, moisture can leak into the base and cause it to shift, thus compromising the integrity of the paved area.
Another challenge is properly preparing the damaged area to take the patch. Any debris left in the crack or hole can prevent the patch from melding with the paving. This means gravel, sand, and any plant material that has taken root must be thoroughly removed before patching.
Cold Patch Limitations
Do-it-yourself repair kits are available, but not recommended. Most of these kits consist of some sort of cold patch material. This could be an asphalt blend, or it may be asphalt mixed with some sort of resin or epoxy that is meant to harden up once it cures.
The problem with cold patch kits is that, at most, they only provide a temporary repair. Since the patching material is spread into the crack or hole cold, it doesn't meld with the existing asphalt. As it cures, it pulls away from the surrounding pavement, allowing water incursion. Eventually, the patch will crumble apart.
Preferred Patching Method
Hot patching is the professional method of repairing concrete. An asphalt paving professional will first clean the damaged area. They will then place a foam filler into the crack if it is very large — this filler allows for temperature expansion so the crack doesn't re-form in the future.
Next, the asphalt surrounding the damage is heated up until it softens. Then, a hot asphalt mix is poured into the crack or hole and compacted into place. The hot patch bonds permanently with the heated asphalt, creating a strong patch that won't break apart over time. Although the patched area is darker than the surrounding pavement, you can be assured it is strong and long-lasting.
An asphalt paving company can be a great resource if you need to patch your pavement.