How Thick Should Your Asphalt Be?
The thickness and structure of an asphalt paving project ultimately depends on the anticipated use of the pavement once it is finished. But there’s more involved, as asphalt pavement involves an entire structure and few critical decision making points involving subgrade materials and drainage.
Here’s what we mean, and keep in mind these numbers are, of course, very generalized.
- Residential driveways typically use 2 to 3 inches of asphalt with 3 being suitable for occasional large trucks or heavy equipment.
- Underneath the asphalt you should have 6 to 8 inches of granular base aggregate.
- Underneath this you have soil. If your local soil is gravelly, rocky, or sandy it will provide good drainage and can stay, bit if your soil is loamy or clay it may need to be excavated and replaced to a certain depth, before it causes serious problems later.
Commercial Driveways and Parking Lots
- Commercial driveways and lots should use 3 inches of asphalt.
- Commercial driveways should also use 8 inches of granular base aggregate, while lots should use 6 inches of granular base aggregate.
- Good drainage soil positioned underneath.
Heavy Duty Commercial Driveways and lots
- Driveways near loading docks, or which will be handling large trucks on a frequent basis, should have a stronger structure, with distinct finish and binder layers leading to asphalt thicknesses of 4 to 7 inches total.
- Heavy duty commercial lots should use 6 inches of asphalt over at least a three inch aggregate base layer.
What happens if your asphalt is too thin?
When asphalt is installed properly the thickness of the material and its natural flexibility spreads out the weight of the load, which is ultimately supported by the base layer underneath. But if the asphalt is too thin the weight isn’t distributed and compresses the material right underneath the tire, causing it to pull away from the surrounding pavement and develop fatigue cracks. Eventually these tiny cracks will spread upwards and outwards, growing quickly larger and causing the surface to deteriorate well before its lifecycle is over.
Stripe A Lot offers high-quality asphalt and paving services for our friends and neighbors in communities all across West Michigan. As our area’s leading asphalt company, we pride ourselves on delivering excellent work at a reasonable price, backed up by outstanding customer service. For commercial and residential paving and asphalt, parking lot maintenance, lot repair, commercial and residential driveways, and more please contact us today at 616-772-2559!