Cracks in asphalt pavement develop for several reasons.  Pavement brittleness, weakened subgrade, and poor construction of the pavement in the first place are some of the causes.  Cracks let water penetrate through the pavement and into the subgrade.  This can soften and even erode the subgrade that supports the pavement.  This results in more cracking and potholes.

Crackfilling and cracksealing is one of the most important steps you can take to prevent this water intrusion and eventual deterioration of your pavement.

Cracksealing refers to the process of placing specialized materials (crack sealants) into working cracks.  Working are cracks have vertical or horizontal movement greater than a tenth of an inch.  Therefore, the material used to seal these cracks needs to adhere to the walls of the crack and be flexible enough to move with the crack without cracking or being pulled away from the crack wall. Cracksealing is the predominant service performed by pavement maintenance contractors.

Crackfilling refers to filling non-working cracks, or cracks with vertical or horizontal movement less than a tenth of an inch.  Since the cracks move little, the materials used to fill them are more rigid and offer more physical support to the adjacent pavements.

Cracksealing Materials:  The two basic types of crack sealants are cold applied and hot applied.  Cold applied materials come in many varieties and are easily purchased at hardware stores and pavement supply stores.  We use cold pour material only when the cracksealing job is very limited such as a small residential driveway, or a small parking lot that has very few or minor cracks.  The other type of material is hot applied.  It is much more durable, has better adhesion, and greater flexibility than cold applied materials.  It is more expensive than cold applied and unlike cold applied material, hot applied material requires specialized equipment and handling. 

The Cracksealing Process: The first step is crack preparation.  For any quality cracksealing project (hot or cold applied) the crack must be thoroughly cleaned.  The sealant material will not bond to the walls of the crack if it is not properly prepared.  We accomplish this preparation by using a combination of mechanical wire wheel machines, routers, forced air blowing, or pressure washing. Once the crack is clean and completely dry the sealant can be applied.  We slightly overfill the crack and use a V-squeegee to create a uniform banded appearance.   In circumstances where traffic needs immediate access, we apply a light coat of black sand to the still hot band of sealant to prevent tire tracking.