In many cases, you can install new asphalt over old asphalt, provided the existing pavement is structurally sound. If the base underneath has failed, an overlay may only hide the problem temporarily, and deterioration can return quickly.
If your parking lot is in need of repair, continued parking lot maintenance is key to a business's reputation and a property's value. Facility managers must constantly be on the lookout for ways to keep up their lot's pristine appearance while minimizing costs and staying within budget.
If your asphalt parking lot needs some TLC, is putting new asphalt over the old a viable option? Or do you have to start thinking about removal and replacement?
(Baywood Business Center, Orange)
What Exactly Is an Asphalt Overlay?
An asphalt overlay isn't the same as just paving a new layer of asphalt over the old material and calling it a day. Instead, an asphalt overlay helps repair the top layer of asphalt, making it like new.
If a paving surface has deteriorated but still retains structural integrity (e.g., it doesn't have a sinkhole or other major structural issues), it can be overlaid with new asphalt.
In the overlay process, the very top layer of asphalt is removed, allowing the new asphalt to blend with the existing material. Uneven or damaged sections of the lot are repaired and/or leveled out before the contractor continues with the rest of the process. The worn-out asphalt surface is paved over with a new layer of hot mix asphalt (HMA), and the new HMA is then applied to the specified areas by an asphalt paving machine. In addition, a glue-like bonding solution (known as "tack") is applied between the old and new surfaces, fusing the two layers together.
As a result of this process, you're actually putting the old asphalt to good use!
Read More: What is an Asphalt Overlay?
Where Does Asphalt Grinding Fit Into the Picture?
Asphalt grinding (also known as "milling") is a simple way to remove the topmost layer of existing asphalt so the overlay can create a smooth, flawless appearance and extend the life of your parking lot. Once the existing asphalt has been milled away, a new layer of tack coat is applied to the surface, creating a strong bond with the new overlay.
Asphalt grinding projects can be big or small. If only a small area of your lot needs to be milled, then your contractor may use a simple walk-behind grinder. For "medium-sized" jobs, many companies use a skid steer grinder with a hydraulic system that can grind through asphalt quickly and accurately. And for large-scale projects, asphalt pulverization equipment is called for. At Empire Parking Lot Services, we provide each of these services depending on the size and scope of the repair job.
When Does a Parking Lot Need to Be Fully Removed and Replaced?
A parking lot needs full removal and replacement when the base or subgrade beneath the asphalt has failed. At that point, no surface treatment will hold.
The process involves excavating the existing asphalt down to the aggregate base. Any areas with compromised subgrade are undercut, regraded, and recompacted before new material goes down. A new asphalt section is then placed and compacted to the specified thickness.
Three conditions point to removal and replacement over overlay:
- The subgrade has failed across large areas of the lot
- Drainage problems cannot be corrected at the surface level
- Elevation constraints prevent adding new asphalt thickness
The evaluation section below covers how Empire Parking Lot Services determines which scope your lot actually needs.
Is an Asphalt Overlay the Way to Go?
In many cases, yes. An asphalt overlay can restore the appearance and performance of a parking lot without the disruption of full reconstruction.
Instead of removing the entire pavement structure, contractors install a new layer of hot-mix asphalt over the existing surface after completing repairs and preparation. Most commercial overlay projects use roughly 1.5 to 2.5 inches of new asphalt, depending on traffic demands and pavement condition.
Compared to full removal and replacement, overlays are generally faster and require less downtime. The key question is whether the existing pavement structure is still stable enough to support resurfacing. That evaluation determines whether an overlay will extend the life of the lot or only temporarily cover underlying failure.
How Empire PLS Evaluates Your Existing Pavement
Before our asphalt paving team recommends an overlay, our foremen walk the property and determine whether the existing pavement can support a new asphalt lift. An overlay only works if the base underneath is still doing its job. Our team walks the property with you before any work is scoped, and end-of-project photos and video documentation are provided upon request.
What Our Team of Asphalt Paving Experts Look For
These are the indicators that tell us whether your lot is a candidate for overlay or whether the base has already failed:
- Surface cracking pattern. Linear cracks and isolated alligator cracking are usually fine for overlay. Alligator cracking covering more than 25 to 30 percent of the lot means the base has lost its load-bearing capacity.
- Pothole frequency and recurrence. A handful of patchable potholes is workable. Recurring potholes that return in the same spots after patching point to subgrade movement, water retention, or lost compaction that an overlay cannot fix.
- Drainage performance. Standing water 24 hours after rain tells us water is sitting on or in the base. Drainage failure must be corrected before any overlay goes down; otherwise, the new surface traps the problem and accelerates the next failure.
- Edge condition. Crumbling, raveling edges along curbs and gate areas tell us the asphalt has lost binder and may not bond well with new material.
- Soft spots or pumping. Another clear indicator is when the existing surface flexes under truck traffic or shows pumping (water and fines coming up through cracks). No surface treatment will correct this.
- Existing pavement thickness. Pavement that's already below structural specification leaves no room to mill and overlay without compromising depth.
- Elevation and grade. Curbs, doorways, and drainage inlets need adequate vertical clearance to accommodate an additional 1.5" to 2.5" of asphalt without creating ADA violations, tripping hazards, or trapping water at building entries.
When Overlaying a Parking Lot Is a Waste of Money
When should you NOT overlay a parking lot? An overlay placed over a failed base is one of the most common mistakes we see on commercial properties. The new asphalt looks great for a few months, then the same cracks and potholes telegraph back through the new surface. The money spent on the overlay is gone, and you're back to square one, with a remove-and-replace still ahead of you.
When two or more of the indicators above show up across your lot, an overlay isn't the right call. In those situations, a remove-and-replace project addresses the actual problem. It costs more upfront, but it lasts. An overlay placed on a compromised base typically fails within two to three years, which means you've paid twice and waited longer for a permanent fix.
Common Questions About Asphalt Overlay
How long will an asphalt overlay last?
A properly installed overlay on a sound base typically lasts 8 to 15 years in Southern California, depending on traffic volume, climate exposure, and maintenance practices. Lots with heavy truck traffic or delivery routes fall on the shorter end of the spectrum. Lots used primarily for passenger vehicle parking, paired with routine asphalt sealcoating every 3 to 5 years and prompt crack sealing, reach the upper end of that range. The single biggest factor in overlay lifespan is the condition of the base beneath the overlay at installation.
Is an overlay as good as new asphalt?
For surface appearance and short-term performance, yes. A finished overlay looks identical to a brand-new lot and rides the same way. For long-term structural performance, no, and that's the honest answer. A full remove and replace gives you a fresh base, fresh sub-base correction where needed, and a full-depth asphalt section. An overlay gives you a new wearing surface bonded to the existing pavement. When the existing pavement is structurally sound, the overlay performs nearly as well at a smaller investment.
Call The Asphalt Overlay Experts Today
What's the simple answer to the question: "Is it okay to put new asphalt over old asphalt?" Yes, if it's done properly as part of an overlay. To sum up:
- An asphalt overlay allows you to use your existing asphalt as a base for new asphalt.
- An overlay can be as simple as grinding down a portion of your existing asphalt, applying emulsion to bind the old and new asphalt layers together, and then compacting the new asphalt to its desired thickness and slope.
- A remove-and-replace project is the way to go when your lot has structural integrity issues or other major problems.
Partner with Empire Parking Lot Services for asphalt repair work that holds up. Contact us at 714-633-0300 today to have our experienced team assist you with your next asphalt repair project.
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