Why Paving Concrete Over Asphalt is Only a Temporary SolutionPosted on August 06, 2021 by Rafael Cantillo
If you have a parking lot with gaping holes and rough surfaces, you're probably considering parking lot maintenance. To save money, you'll probably consider paving concrete over asphalt instead of repaving the entire driveway or parking lot. Unfortunately, taking shortcuts in parking lot maintenance costs you more in the long run. Let's discuss.
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What Happens When You Pour Concrete Over Asphalt?
To save money, municipalities, commercial building owners, and homeowners often pave concrete over asphalt. This parking lot maintenance technique is called white topping.
Paving concrete over asphalt may work in the short term, but it's not a good technique. In white topping, asphalt works as the parking lot base for the concrete. The base should be approximately 2 to 3 inches.
Before pouring the concrete over the asphalt base, you have to inspect the asphalt for cracks and holes. If there are gaps of more than 2 inches, you have to fill them to ensure the concrete application goes on smoothly.
Next, you need to pressure wash the surface to remove the debris and create a good bonding surface between the asphalt and the concrete. You can also scrape the top surface of the asphalt away to retain the height of the driveway and parking lot after pouring the concrete.
The thickness of the concrete layer depends on your needs. For example, for residential parking spaces for your properties, 2 to 4 inches of concrete is adequate. However, for commercial parking lots, 4 to 8 inches is sufficient.
What are the Disadvantages of Paving Concrete Over Asphalt?
Asphalt has a different composition from concrete. Usually, a concrete subbase is a layer of gravel that holds the concrete mud. On the other hand, asphalt has a greasy tar that doesn't provide a suitable base for concrete adherence.
A proper subbase is essential to prevent the concrete from sinking or cracking. If the asphalt has cracks and gaps that aren't correctly filled or cracks develop over time, the concrete on top may also crack.
Costly in the Long Run
Paving concrete over asphalt is a technique usually done to save cash in the short term. However, the concrete cracks or scrapes away in the long run because of poor adherence to the base. It costs more to pave concrete over asphalt in the long run instead of repairing the parking lots and driving ways with new layers.
Are There Situations Where Asphalt is Installed Below Concrete?
There are situations where contractors pour concrete over asphalt. Once the base layer is in place, the contractor adds 3 inches of porous asphalt to allow good drainage. The asphalt provides a leveling layer course and prevents compaction from heavy vehicles. However, this process is unsuitable for old, deteriorating asphalt.
Small holes and gaps in asphalt affect parking lot usage. It's uncomfortable to drive on uneven asphalt. Usually, an asphalt parking lot can last for approximately ten years, depending on the traffic, quality of installation, and weather elements.
Over time, common problems such as potholes, depressions, and cracks appear on the parking lot. If the deterioration is severe, asphalt replacement may be a better option. However, if the asphalt is still in great condition, you can contact Empire Parking Lot Services for asphalt repair. There are several options to consider for asphalt repair instead of using a concrete layer.
This technique is used when the asphalt layer has deteriorated in one specific area. In such instances, potholes develop, hence the need for quick and inexpensive patching. To ensure longevity, Empire Parking Lot Services may remove and replace the entire depth of the asphalt. Therefore, it's crucial to fix potholes as soon as they appear to avoid damage to vehicles.
This is a repair technique that preserves the subbase below the asphalt. Sealing cracks prevents water from penetrating the aggregate base layer. Cracks develop due to sudden temperature changes and heavy traffic loads over years of asphalt parking lot use. To fix the cracks, we use a rubberized crack sealer to prevent water penetration. We also cut the edges to ensure adhesion. Usually, sealing is essential every 2-3 years.
Sealing your asphalt parking lot extends its life and use. It also reduces maintenance costs and prevents water penetration into aggregate layers. We reapply a seal coat on the asphalt every 3-7 years to improve the longevity of the asphalt after repair.
Overlaying is a maintenance technique where a new layer of asphalt is spread over the existing asphalt parking lot. The new layer is approximately 2 inches thick. Overlaying improves the strength of the asphalt and seals cracks and holes. It also provides a smooth parking surface while lowering maintenance costs.
Concrete Repair and Installation Services
If you want to replace your asphalt parking lot instead of adding an overlay and sealant coat, consider installing a concrete parking lot. Installation means stripping the asphalt to create a proper base for the parking lot.
Asphalt has tar, which is greasy, especially in hot weather, and forms a poor base for the concrete. Stripping the asphalt is, therefore, the best way to install a new commercial parking lot. Concrete parking lots perform best with a compacted subbase and subgrade. Sufficient reinforcement is also crucial to strengthen the parking lot for commercial use.
Just as asphalt, concrete parking lots also develop cracks and potholes over time. These problems require commercial concrete parking lot repair to prevent minor issues from building up into costly problems.
Parking Lot Maintenance in Southern California
When you hire Empire Parking Lot Services for asphalt and concrete parking lot repair, we conduct an assessment to recommend the best solutions. Although paving concrete over asphalt is a quick fix to repair uneven, cracked, and deteriorating asphalt parking lots, it doesn't last long.
We recommend asphalt overlays and sealing for asphalt parking lots that are still in shape. However, if the asphalt parking lot has severe damage, we recommend installing a new asphalt or concrete parking lot.
Empire Parking Lot Services is ready to repair and install asphalt and concrete parking lots that will serve you for a long time. Contact us at 714-633-0300 to have our experienced team assist you with your next parking lot maintenance project.