Can you put asphalt over dirt?
Quick answer: Not directly. Asphalt laid straight onto bare dirt cracks and sinks, because soil shifts when it gets wet or freezes. The dirt has to be graded and compacted, then covered with a compacted stone base, and the asphalt goes on that.
If you already have a gravel driveway in good shape, the news is better: that gravel can serve as the base, and yes, you can blacktop over gravel.
If anything, Over 90 percent of the roads in the US are surfaced with blacktop (preferably known as asphalt). This is because not only does it give the road an enticing appearance, but it also entails several other benefits.
Converting your Gravel Driveway into Asphalt
Adding a layer of asphalt over your gravel driveway is one of the most inexpensive options that you can use to pave it. However, if the project is not done accordingly, it can result in the blacktop becoming brittle and dry, leading to a small crack on the surface.
The good news is, contacting a professional contractor will assist you with any obstacle that you may encounter when paving your driveway. They’ll also answer any question that you may have regarding the project, not to mention, they will use the appropriate steps.
One major issue contributing to the asphalt breaking down prematurely is water; therefore, the contractors will check the grade and conduct a runoff evaluation. This step is essential to prevent water from later pooling over the surface.
A panel will be laid underneath it to create a sub-base that is stable enough to hold the asphalt. Afterward, the contractors will add the last layer to make the gravel driveway solid.
Once that is done, it is essential to conduct regular maintenance, such as:
This will prevent it from breaking or cracking, significantly expanding its lifespan.
Different Alternatives that you can use
In comparison to blacktop, chip and tar is a cheaper method to pave a gravel driveway. However, the texture may tend to be rougher due to the combination of stones and asphalt.
Once the blacktop is already in place, this process is then more straightforward since all you have to do to finish off the surface is add stones over it. It is double the price of gravel, but it makes your driveway appealing without having to spend a fortune.
The Do It Yourself Option
Paving your gravel driveway can cost an arm and a leg; fortunately, there is a more straightforward tactic that you can use with just a few materials. The first step is to evaluate the quantity of loose dirt and gravel you have.
Then, head over to your local supply store and purchase the materials you may require to pave your driveway. If you aren’t familiar with what you may need, consult the merchant since they may assist you.
Once you have attained your materials, mix the dirt with the gravel. It is advisable to do this after a rain when everything is wet. Afterward, give your driveway a scrape then let it dry. This will provide your driveway with a smooth texture and a good look.
Take note of the Environment before Paving your Driveway
Now that you have familiarized yourself with whether you can add asphalt over dirt, certain factors should remain etched in your mind before diving into this idea, such as checking the local building codes.
This is because certain building jurisdictions will require you to get a permit before paving a gravel driveway.
Frequently Asked Questions
Can you put asphalt directly on dirt?
No. Asphalt laid straight onto bare dirt cracks and sinks, because soil shifts when it gets wet or freezes. The ground has to be graded, compacted and covered with a compacted stone base first.
What goes under an asphalt driveway?
A graded and compacted subgrade, then a base of crushed stone placed in layers and compacted. The asphalt is paved on top of that base.
Can you pave over an existing gravel driveway?
Yes, if the gravel is firm, compacted and drains well. It is regraded, topped up with stone where it is thin, compacted again and then paved.
What happens if asphalt is laid without a base?
It fails early. Without a stone base to spread the load and drain water, the surface ruts under the wheels, cracks and sinks within a few seasons.
Does the dirt need to be compacted before paving?
Yes. The soil is shaped for drainage and compacted, and any soft or wet spots are dug out and filled with stone before the base goes down.
About the author
William Stanley owns Willie’s Paving, which has paved driveways, parking lots and roads across Central Pennsylvania since 2000. He has over 30 years of hands-on experience in asphalt paving, sealcoating and repair, and the advice on this page comes from that work.
Pennsylvania Home Improvement Contractor PA003370. Questions about your own driveway or lot? Call (717) 932-8920 or ask for a free estimate.
