What Should Be The Thickness Of Asphalt Driveway
One of the most common questions that we are asked is when it comes to paving a driveway is how thick the asphalt should be? It is an important question and there is not one quick and easy answer but instead, it depends on what surface is already in place. By focusing on the thickness of the asphalt driveway it can help provide longevity. This will ultimately raise the property value of a home.
Resurfaced Pavement
Let’s briefly speak on asphalt resurfacing methods. When resurfacing existing pavement the asphalt covering should be 2 inches thick. This also requires the pavement to be in good shape, relatively level and without any subsurface impediments like tree roots and this may not be able to be determined until the top layers are removed though there are usually signs that can be seen on the surface.
Stone Surface With A Good Base
A stone surface with a good base requires 3 inches of asphalt. This allows the asphalt to settle around the stone providing strength. If the subgrade is not stabilized properly it can lead to many serious issues and the stone sinks into the subgrade providing strength and stability but the amount of asphalt must cover these rocks up.
New Construction
Use this section as an asphalt thickness calculator. A newly constructed surface is done in two layers, a 2.5-inch thick binder with a 1.5-inch thick top layer. The binder provides strength, coats loose material and plugs voids. It provides a strong enough surface for heavy equipment to work on to apply the top layer. That layer is bound to the lower layer and is able to move with it making it more durable. New construction typically lasts the longest. Anything smaller than these measurements is typically considered a bad asphalt driveway.
It should also be noted that thicker asphalt layers will be necessary for driveways that are used by heavier vehicles like commercial trucks, garbage trucks or heavier personal vehicles. These vehicles will cause damage to an asphalt driveway meaning it will need to be thicker to make it stronger. The thickness can be determined by the subgrade underneath and this may not always be practical. It is important to let us know beforehand so we can engineer your driveway so it will be able to stand up to this kind of traffic.
With all this information you are able to judge your asphalt paving thickness.
If you don’t know how to lay asphalt yourself than allow us to help. We take pride in our work, let us prove it.
Get one of our professionals to pay you a visit today!
Call: 717-932-8920
Asphalt Driveway Thickness Chart
How thick an asphalt driveway should be depends on what is underneath it.
These are the thicknesses we build to:
| Situation | Asphalt thickness | Why |
|---|---|---|
| Resurfacing over sound existing pavement | 2 inches | The old surface carries the load, so a 2 inch overlay is enough when it is level and sound |
| Over a compacted stone base | 3 inches | The asphalt has to settle around and fully cover the stone to gain its strength |
| New construction (two layers) | 4 inches total 2.5 inch binder + 1.5 inch top |
The binder plugs voids and carries equipment; the top layer bonds to it and moves with it |
| Heavy vehicles, trucks, commercial traffic | More than 4 inches | Engineered to the subgrade. Tell us about heavy traffic before we build |
Anything thinner than the figures above is generally too thin to last.
Key Takeaways
- 2 inches when resurfacing over sound pavement.
- 3 inches over a properly compacted stone base.
- 4 inches total for new construction, built in two layers.
- More than 4 inches where trucks or commercial vehicles will drive.
- The base matters as much as the asphalt. Thickness cannot fix a bad subgrade.
Frequently Asked Questions
How thick should an asphalt driveway be?
Two inches when resurfacing over sound existing pavement, three inches over a compacted stone
base, and four inches total for new construction, laid as a 2.5 inch binder course with a 1.5 inch
top course. Heavier vehicles need more.
Is 2 inches of asphalt enough for a driveway?
Two inches is enough only as an overlay on pavement that is still level and structurally sound.
On a stone base or new construction, two inches is too thin and will fail early.
Why is asphalt laid in two layers?
The binder course is a coarser mix that provides strength, plugs voids and is strong enough for
equipment to work on. The top course bonds to it and flexes with it, which makes the finished
driveway more durable than a single thick layer.
Does a thicker driveway last longer?
Up to a point. Thickness matters, but a properly prepared and compacted base matters just as
much. Thick asphalt over a poor subgrade will still crack and settle.
How thick should a driveway be for heavy trucks?
More than the standard four inches, with the exact figure engineered to the subgrade. If garbage
trucks, delivery trucks or heavy equipment will use the driveway, tell us before we build so we can
design for it.
