Through years of research, I have concluded that the majority of sealcoating failures (e.g. premature wear, flaking, and peeling) happen due to bonding problems between the sealcoating and pavement surface. While sealcoating manufacturers are meticulous in detailing the aspects of material and surface preparation prior to sealcoating and urge the applicators to comply, it’s still not always possible to cover everything considering the myriad of pavement types, ages and conditions. In this article we will review the causative factors and remedies that are practiced as good sealcoating practices.
The #1 rule in most sealcoating rulebooks is that the pavement should be clean – free of dirt and debris, free of surface defects, and suitable for sealcoating.
For the proper bonding of the sealcoating, it is essential that the surface be cleaned as thoroughly as possible. The adage that “a coating is as good as the surface that it is applied on” holds true for all coatings. If the surface is not clean, the coating will not bond and with time and usage it will flake or peel off. The extent of cleaning will depend upon its condition; it may require simple air blowing or more involved scraping, wire brushing, blowing or pressure washing.
Beyond being free of debris, the pavement should be free of surface defects too, which means the applicator needs to repair cracks, surface alligatoring, patching and oils spots. Sealcoatings are not repair products; they are coatings to protect and preserve the surface. Non-working cracks should be filled and working cracks sealed. Similarly, alligatored surfaces need to be thoroughly examined for any signs of the base failure.