Why Crack Seal?
Crack sealing is the single most cost effective pavement maintenance process you can perform, especially if your budget is tight. Crack sealing will prevent water from infiltrating down to the sub-base and creating pot holes and alligator cracks, along with preventing the cracks from spreading further. In some instances, crack sealing can delay an overlay and help extend the life of your parking lot by up to 7 years.

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Types Of Cracks:
There are several types of cracks that you may find present in your asphalt parking lot. Below is a description of them and the suggested corrective maintenance method.

Alligator Cracking:


Alligator cracking is caused by inadequate base or poor pavement thickness. Alligator crack usually start off as a crack in the pavement. If the cracks aren�t sealed prior to Winter, water will infiltrate into the sub base and allow water to remain under the pavement. When the temperatures fall below freezing, the pavement will even heave at times. When the freeze thaw cycle is over in the spring, a void will remain under the cracked surface. Continued vehicle or heavy truck traffic will depress the alligator cracked area and a pot hole will begin to form and will lead to total surface failure in a relatively short period of time depending on traffic density. If the alligator cracks were caused by inadequate sub base, depending on the severity of the area and if the area of compromise under the pavement is localized, the cracks may continue to sprawl or may stay localized.

Recommended Repair:
Saw Cut & Removal of the failed asphalt (See: ASPHALT REPAIR)

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Random Cracks / Linear Cracks:


Surface cracking is the most common defect found in pavements. Cracks can run perpendicular (transverse), parallel (longitudinal) to the direction of traffic or in a meandering random pattern across the surface. Transverse, thermal cracks caused by cold temperature contraction of the surface layer will occur to some degree in all asphalt pavements. Longitudinal cracks can be caused by opening of paving lane joints or by repeated over-stressing of the wheelpath area by heavy aircraft traffic. Secondary cracking may eventually develop which may start to transform in Alligator Cracks. Environmental factors also play a large role in the structural breakdown of pavement cracks. Water can enter the crack, washing out fines from underneath and eroding support for the pavement. Just because a pavement is cracked does not mean that it has failed. A pavement is only considered to have failed when the cracking has become so severe that the structural integrity of the surface becomes a liability.

Recommended Repair:
Hot Rubberized Crack Sealing (See: CRACK SEALING)

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Block Cracking


Block cracking is identified by intersecting transverse and longitudinal cracks forming rectangular blocks. These crack vary in size. Block cracking may appear to be similar to alligator cracking but it is not limited to wheelpath locations (i.e. block cracking is not load-related) and will frequently occur throughout the entire pavement surface. Block cracking is normally found in older asphalt surfaces. The cause of block cracking usually is a �surface deficiency� and not a sub base problem. It is not uncommon to excavate a surface course of asphalt and find no cracks that were reflecting up from the binder course of asphalt. Block cracking is usually attributed to not having enough traffic on an older parking lot that has become oxidized, improper asphalt installation and can even be caused by a deficient asphalt mix.

Recommended Repair:
Asphalt Resufacing With A Geotextile Crack Retardant Fabric (See: Asphalt Resurfacing)

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Reflective Cracks



How Reflective Cracks Develop:

When cracks are preexisting in an asphalt parking lot and the parking lot is resurfaced with out either sealing the cracks or installing a Geotextile Paving Fabric prior to resurfacing the parking lot, the existing cracks will reflect back up into the new overlay and resemble the exact pattern that was present before the parking lot was resurfaced. Depending on climatic conditions, typically cracks will reflect back into an overlay at a rate of about 1� per year. For example: if you install a 2 �� overlay that is compacted to a 2� average surface, on /about the second year the cracks will resurface.

Recommended Repair:
Asphalt Resufacing With A Geotextile Crack Retardant Fabric (See: Asphalt Resurfacing) Crack Sealing (See: Crack Sealing)

In the above diagram, a geotextile paving fabric was installed prior to resurfacing. This fabric in conjunction with crack sealing will help absorb the stress from below the overlay and will prevent the cracks from reflecting back into the surface.

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Crack Sealing Process:
The cracks are first cleaned with a heat lance. The heat lance mixes compressed air with propane to create a �flameless� stream of air which heats and dries out the crack along with removing any vegetation and debris. The heat lance also helps draw out the asphaltic oils in the pavement to help create a thermodynamic bond with the new crack sealer. We can also route the cracks to create a reservoir for the new sealant to bond to.. This process is recognized by the Federal Highway Administration (FHA) as the most effective method for crack sealing to insure longevity. When option is elected by our customers, the crack sealing comes with a 2 year warranty against failure. In the event the cracks re-open during this time period, we will return to reseal them at no charge.
Upon proper preparation, heat lancing or routing, we will then apply a hot poured rubberized crack sealer that will expand and contract with the pavement. We apply 4 different brands of Crafco hot rubberized crack sealants. Sealants are chosen for each job type to find the best selant for your application.
(Crack sealer being injected with a wand / disc applicator in a 3� over band followed by an application of black beauty slag to allow traffic onto the surface immediately and to help the crack sealer bond with the pavement sealer)

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Joint Sealing Process:
We can apply a specialized joint sealer to seal any asphalt / concrete or concrete/ concrete joints to prevent water infiltration to the sub-base.
(Joint sealer being applied to an asphalt / concrete joint at a self storage facility to prevent water from infiltrating the sub-base at the inverted drainage swale in the center of the drive isle)