Overlaying is the process of putting a new layer of asphalt over existing asphalt. While it can often be a more cost-effective solution than asphalt replacement, it isn’t always the best solution. There are important factors other than cost you need to consider. Understanding these factors will help determine whether or not an asphalt overlay is the best solution.
Extent of Existing Damage
The current condition of your parking lot is the first thing an asphalt professional will evaluate. Extensive structural damage such as large potholes, root damage, or ruts in the surface will require asphalt replacement, not an asphalt overlay. Minor surface cracks or shallow tire rutting can be eliminated by milling the existing asphalt surface. This will allow the overlay to adhere to the existing surface and cure properly. With full depth cracks, deep tire ruts or underlying base problems such as moisture or deformation, milling wouldn’t be sufficient to effectively prepare the surface for an asphalt overlay. Under these circumstances, it would be necessary to do partial asphalt replacement before putting down an overlay or skip the overlay and completely replace the existing asphalt.
Parking Lot Size
An overlay can be installed over any size asphalt parking lot. However, the size of the parking lot can significantly impact your decision when choosing between an overlay and replacement. There is more prep work than you may think to be done before installing an asphalt overlay. On a larger parking lot requiring extensive preparation, an overlay may not be the most cost-effective option. However, with a small parking lot, it could be the ideal solution.
Elevation and Pitch
When considering an asphalt overlay, the elevation of the parking lot is another factor that comes into play. There needs to be enough room to install the overlay without interfering with drainage. To install an overlay, there needs to be a 1 ½” minimum of asphalt thickness when complete. This means the existing asphalt will need to have settled far enough or be milled down to allow for the proper thickness. If the asphalt hasn’t settled enough where it meets the building and there is no apron against the building, there will not be enough room for the necessary milling. A section of the pavement will need to be sawcut and removed. It can then be repaved at a lower height, allowing the overlay to be flush with the building.
With a flatter parking lot, the amount of milling necessary to properly prepare for an asphalt overlay may increase. If the amount of milling needed is extensive, it may be more cost effective to replace the asphalt.
While an asphalt overlay can be installed over a parking lot with minor surface cracking, those cracks will eventually reappear in the overlay. How long before this happens depends on the surrounding soils conditions. If the soil is sandy, it may take longer for cracks to appear as this type of soil drains better than clay soil types.
Expectations – Asphalt Overlay or Replacement
If the asphalt has oxidation with only minor surface cracks, reduced skid resistance, shallow tire ruts or
minor water intrusion, an asphalt overlay can be a good solution. The life expectancy of an overlay averages 10-15 years under ideal conditions. The life expectancy of asphalt replacement averages between 15-20 years. To determine which is the best solution, the existing parking lot needs to be thoroughly evaluated and all of these factors taken into consideration.
Consult with the Professionals
Certified Asphalt can evaluate your parking lot and determine the best solution. We provide full-service commercial and residential asphalt paving services to Ocean County, Monmouth County, and surrounding areas in New Jersey. We specialize in asphalt paving, milling, asphalt repair, seal coating, and pavement maintenance. Family owned and operated for three generations, we have the skills and experience to deliver quality services at affordable rates. Fully licensed and insured, we guarantee your complete satisfaction! Contact us today for a free estimate!