One of the great construction debates is to sealcoat or not to sealcoat asphalt pavement. Let’s review the primary purpose of sealcoating and then the common complaint. Sealcoating asphalt (usually driveways or streets) provides a thin layer of fine aggregate, oil and minerals to help protect and “seal” the aggregate asphalt materials that make up the pavement. It protects it from environmental factors that breakdown asphalt such as water/moisture, UV rays, and temperature change. Sealcoating is similar to painting. It protects the surface, while at the same time giving it an aesthetically pleasing and uniform appearance.
Which brings us to the primary criticism of sealcoating. Everybody loves a freshly sealcoated driveway. It looks all shiny and new! But after one plow season, you’re left with blade marks and tire tread patterns. After a year or so, light spots start appearing from areas that hold water or are exposed to heavy traffic. What a waste of money that sealcoating was! After a couple of years the asphalt blends back to that uniform gray look. Did it really matter or make a difference spending the money to sealcoat?
Yes, it did! Unprotected asphalt will undoubtedly break down sooner than asphalt that has been sealed. This is a similar process to what happens with exterior wood surface. If left unprotected by paint or stain, fibers will break down and rot away. The secret to sealcoating is having realistic expectations on how long that shiny new looking driveway will last.