Asphalt cracks can lead to more extensive damage in a parking lot over time, as they will continue to widen and worsen if they aren't properly repaired. Fortunately, most cracks can be fixed without the need for a full parking lot replacement.
No repair can begin unless the cracks are cleaned out. A paving service will use one or more methods to complete this. For a very narrow crack, it may only be necessary to brush the area hard with a stiff brush so any debris is dislodged. Larger cracks may require weed removal or pressure washing to get all of the debris out of the crack.
2. Expansion Fills
Large cracks often develop in areas where stress causes pavement to spread apart, either from traffic driving over the area or due to thermal expansion and ground shift. The repair crew will put foam or rubber rods into the crack, tamping them down and into place. These rods provide some elasticity once the crack is filled, which will help prevent a new crack from forming as a result of expansion at the site.
The next step is to fill the crack with a patch material. Most asphalt crack patching compounds are a combination of asphalt mixed with a flexible polymer. The patch material is forced into the crack, no matter how small the crack may be. If an expansion fill was used, it will be completely covered by the patching compound. Cracks are overfilled, and then the excess is scraped away and leveled so that the parking lot surface remains smooth.
4. Sealant Application
After the patching compound cures a sealant is applied over the top. The purpose of the sealant is twofold: it prevents the patch compound from peeling up and degrading, and it also slows weathering damage from UV light and moisture exposure. This extends the useful life of the patch so that the patch doesn't fail and the crack doesn't reopen.
Sealcoating is not always completed after patching a crack, but it is recommended if there were several patches put in or if it has been more than a couple of years since your parking lot was last sealcoated. A sealcoat consists of a mix of asphalt and sealants. It's painted over the lot paving to create a water- and weather-resistant surface. An additional benefit is that the sealcoat mix also covers minor color variations, so the crack patches won't be as obvious once the sealcoating cures.
Contact a commercial paving service if you need your parking lot asphalt to be repaired.