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How Thick Should an Asphalt Driveway be Paved

Asphalt thickness is key when you’re installing a residential driveway. Many homeowners choose asphalt driveways because they are both durable and low-maintenance. So, how thick should the asphalt driveway be?

The thickness of your asphalt driveway is crucial to consider during asphalt construction. The proper thickness of the asphalt will affect the driveway’s durability and how long it will last. Your needs and budget should determine your asphalt driveway thickness.

A thick layer is mostly needed for business buildings or driveways that experience a lot of wear and tear.

Residential Paving

The average residential driveway is between 2 and 3 inches of asphalt deep, with the recommended depth being 3 inches to avoid complications from large vehicles or heavy equipment.

Having 6 to 8 inches of granular base aggregate is crucial for preserving your asphalt. If the soil in your area is gravelly, rocky, or sandy, it will drain well, and you won’t have to do anything to it. Soil loamy or clayey in texture may need to be excavated before construction to avoid future problems.

Commercial Parking Lots

All commercial parking lots have a recommended thickness of 3 inches of asphalt. Commercial driveways should use 8 inches of granular foundation aggregate, while lots should only use 6. The soil under the driveway should also have good drainage to ensure long-lasting results.

Heavy Duty Commercial Driveways and Lots

Driveways adjacent to loading docks or those which will receive repeated heavy truck traffic should have stronger construction, different finish, and binder layers for an asphalt thickness of 4 to 7 inches. A six-inches of asphalt layer should sit atop a three-inch aggregate base for commercial lots that will experience high traffic.

Asphalt Paving Mixture

Asphalt components are made up of two main ingredients: aggregate and asphalt binder. The asphalt binder and aggregate are mixed in a hot mix plant and placed on the roadway. The pavement is then compacted to create a strong and smooth surface.

Aggregate

The rock, stone, or crushed limestones are mixed with the asphalt binder. 

The aggregate affects the strength and flexibility of the finished product. Coarser aggregates produce a stronger but less flexible pavement, while finer aggregates produce a weaker but more flexible pavement. 

The size of the aggregate used also affects drainage. Larger aggregates allow water to drain more easily, while smaller aggregates tend to trap moisture.

Asphalt Binder

It is a sticky, black, viscous liquid or semi-solid that acts as a binding agent. It is made up of bitumen, a by-product of the petroleum refining process.

The ratio of asphalt binder to aggregate is important because it determines the strength and flexibility of the finished product. A higher asphalt binder to aggregate ratio means a stronger and more flexible pavement.

A lower asphalt binder to aggregate ratio means a less flexible but more durable pavement. The asphalt binder is also what makes the pavement sticky and black.

The amount of asphalt binder can be adjusted to meet different needs.

The Consequences of an Asphalt Driveway That is Too Thin

Asphalt is designed to distribute a load’s weight across its surface evenly. The material is pliable and will eventually be upheld by the bottom layer beneath it.

If the asphalt layer is too thin, the car’s weight isn’t evenly distributed. Without that even distribution, the pressure from compression causes material beneath the tire to pull away from adjacent pavement and creates fatigue cracks.

These flaws will eventually become larger and spread out, growing quickly and causing the surface to deteriorate long before the product’s lifecycle is complete.

Advantages of Choosing a Thicker Asphalt Driveway

If you frequently experience extreme weather conditions where you live, opt for a thicker driveway. Asphalt regularly sealcoated will better withstand weather elements such as temperature extremes and heavy rainfalls. The asphalt can expand or contract in extreme heat or cold, which then causes cracking.

Generally, a driveway constructed properly with thicker asphalt will be of higher quality and last longer.

The installation cost is the only thing thicker asphalt driveways have going against them. However, the extra money you spend on a thick asphalt driveway is worth it in the long run.

Professional Asphalt Contractors

With over three decades in paving industry practice, our team at Boswell’s Paving is dedicated to giving you the best possible asphalt paving. We know how important it is to have reliable and high-quality pavement, which is why we only use the best materials and expert contractors.

Keep the thickness of your asphalt in mind if you are paving a new driveway. Although a thicker driveway paving will cost more upfront, it will last longer and be more durable in the long run. If you’re unsure which paving thickness is right for your needs, reach out to Boswell’s Paving- we’d be happy to help you make a decision.