When it comes to any type of residential home improvement or maintenance project, it’s critical that you equip yourself with as much knowledge as you can so that you can make as educated of a decision as possible in terms of how to proceed.
Let’s take a closer look at the key terms you’ll need to familiarize yourself with before moving forward with your driveway paving project (in alphabetical order below):
- Asphalt: A mixture of aggregates, binder and filler that is used for constructing and maintaining driving surfaces. Asphalt, or bitumen, is a sticky, black, highly viscous liquid or semi-solid form of petroleum that is typically mixed with sand or gravel to surface driveways and roadways.
- Base layer: Typically made of quality crushed gravel, this rock is generally 1-2 inches in diameter and performs double duty by establishing a solid, reliable foundation while providing adequate drainage; both critical factors in driveway construction.
- Binder asphalt: A coarser grade of blacktop (than asphalt) that contains a higher percentage of larger stones, which, when added to the asphalt mix, increases stability. The binder asphalt functions to increase the load factor for which the driveway can endure before breaking or cracking. This is usually 40mm-50mm thick.
- Blacktop: This is almost always an asphaltic concrete made from liquid asphalt cement, sand and gravel. The difference between blacktop and asphalt is that blacktop is heated to approximately 150 degrees celsius, whereas asphalt is only heated to 120 degrees celsius. Asphalt has a higher bitumen content, which means that it’s less porous and more resilient to wear and tear from high traffic. (This makes it a more optimal solution for major highways.)
- Subbase: The bottom layer of crushed stone that will sit on top of the subgrade and provide structural strength and integrity to your driveway.
Subgrade: The native material underneath your driveway, or the layer of soil that provides support to the subbase.
- Wearing course (asphalt): The wearing course is the surface layer of a pavement that takes the wear of traffic. Asphalt wearing course is a gap graded, ultra thin hot-mix asphalt (HMA) mixture applied over a thick polymer modified asphalt emulsion membrane. The high binder content seals the underlying surface, which protects it from water infiltration and slows down the aging process.
Here is what you need to know before hiring a New York or New Jersey paving company to tackle the project of paving your driveway:
It’s all about that “base”…
In order to have the best asphalt driveway, you need to have a solid base. Using quality crushed gravel as a base to your blacktop is an ideal solution for high quality and long-lasting durability; this layer is typically, at minimum, 2 inches thick. “Conbit” is another option and refers to recycled concrete and asphalt that is crushed and reused. These crushed coarse materials have jagged surfaces that will compact and lock together in a tough, settle-resistant matrix. Additionally, a binder like cement dust may be added to hold it all together. Residential driveways typically require 6 to 8 inches of granular base aggregate underneath the asphalt. So, before you can lay your base, you first need to prep your subgrade and subbase layers.
…And subbase, too
The subbase is the bottom layer of crushed stone that will sit on top of the subgrade. This layer is made up of large crushed stone aggregate that will provide structural strength and integrity to your driveway. The best subbase for a driveway is typically a compacted layer of aggregate, such as crushed rock, gravel, or limestone. This layer should be at least 4” thick, and should be laid on top of an undisturbed subgrade. The subgrade refers to the native material underneath your driveway. In other words, it is the layer of soil that provides support to the subbase, which is the concrete layer on top of it.
How do all of the layers connect in a driveway paving project?
Now that you’re informed about industry-specific terms and more about the driveway paving process itself, this is the best way to sum it up: the wearing course is typically placed on the binder course which is then laid on the base course. This is typically placed on the subbase, which rests on the subgrade.
Driveway Maintenance Tips
Once your new driveway has been installed, here are some maintenance to keep in mind to ensure durability and reliability:
- Do not drive or park in your driveway for at least three days after installation (time frame might be even longer if the temperature is very hot). Your driveway will harden and soften depending on the weather.
- Avoid using power steering on your driveway as it will tear up your driveway and may leave tire marks.
- Do not use any sharp objects on your driveway during the curing process as this can take up to two years. This means items like: lawn furniture, car jacks, gas grills and even kickstands on bicycles, as these objects have the potential to scar or leave marks in the driveway.
- Consider putting top soil around the edges of your driveway to build them up, and avoid driving off the edge of your driveway since that can cause it to crack.
- Approximately one year after installation, contact a professional paving service like Pavemaks to apply a seal coat to your driveway, and then reapply every two years going forward.
Have questions about a driveway project you’re planning? Reach out to us for a free estimate or to speak to someone directly about our specific process.