Asphalt Seal Coating
At Pro-Coat, we will treat your asphalt like it’s our own. Not all companies are the same when it comes to seal coating. To the untrained eye, asphalt seal coating jobs done by different companies may look the same upon completion, but the question is: will they stand the test of time?
Why seal asphalt?
Asphalt has many drawbacks that relate to its chemical makeup. Asphalt is a very complex mixture of thousands of chemicals which are predominantly open chain in structure with a considerable degree of un-saturation within their molecular structure. This open chain provides easy access to weather, salt and various chemicals to attach and disintegrate the asphalt molecules. As these asphaltic molecules disintegrate, the asphalt in the pavement loses much of its original properties, such as binding and waterproofing. The first sign of breakdown is the asphalts color changing from brown to gray. The asphalt turns gray after it starts to release the asphalt binder that binds it together. As the asphalt starts to dry up, it will form to its base. If time is not taken creating the base underneath the asphalt, these problems will find their way to the surface usually within a year resulting in cracking.
After the binding oils are released, minor cracks will start to develop which will widen and deepen over time. If the cracks are not repaired at this stage, water seems into the base courses and damages the pavement’s load bearing capacity. This will be evident by rutting, shifting, and “alligatoring”. At overlaid or completely removed and reinstalled with a protective coating that resists attack by the elements that destroy asphalt in the first place.
At this point, the asphalt usually needs to be overlaid or completely removed and reinstalled with a protective coating that resists attack by the elements that destroy asphalt in the first place.
What are the different types of sealer?
There are two primary types of seal coating materials used on the market today: those made from refined coal tar and those made from asphalt. Refined coal tar is a byproduct in the coking process in the steel industry. Coal tar sealers were introduced in the 1950’s and have been used primarily to protect off-street pavement surfaces.
Asphalt base sealers have become very popular in recent years due to coal tar shortages, but asphalt emulsions resistance to petrochemicals and solvents has yet to be overcome. Asphalt emulsions are more user friendly, practically odorless and do not irritate or burn the skin, but just do not hold up as well over time. In many applications asphalt base sealers have problems bonding to the polished stone in asphalt after the first winter. In late season applications with asphalt base sealer, it often looks like the asphalt was not even sealed.