ASPHALT DRIVEWAY PREPARATION – IT’S ALL ABOUT THE BASE

Anything built from the ground up needs to have a solid foundation. That includes a new asphalt driveway. Making sure you have the proper base is a key factor in asphalt driveway preparation. The quality of the base will impact the quality of the finished product and its longevity. Although you won’t be installing your driveway, you should have a general understanding of the process. It will help you ask the right questions and hire an asphalt contractor who will complete the project properly. 

Old Driveway Removal

If you are replacing an existing driveway, all the old pavement will first be removed. Heavy equipment such as bobcats, front-end loaders, and dump trucks are used to do this. The old asphalt is hauled away to be recycled and used again.

Grading and Slope

The ground where the new driveway will be installed must be graded to provide a level surface. At this point in the process, the slope of the driveway is also established. The slope allows water runoff and drainage to keep water from pooling on the driveway. This is an important part of asphalt driveway preparation as water is one of the primary causes of asphalt damage.

If your new driveway has an incline, that will allow water to run down and away from the driveway. However, if your driveway is completely level, the ground will be built up slightly to allow water to run off the side of the driveway and drain.

The Sub-Base

Once the slope is established, you have the sub-base or sub-grade. The sub-base is then compacted. Rollers and vibrator plate compactors are used to complete this step in asphalt driveway preparation. If done incorrectly, the sub-base will settle and create voids beneath the asphalt. The weight of vehicles on the driveway will cause the asphalt above the voids to crack and cave in, thus creating potholes.

The Base

With some driveways, a properly graded, sloped, and compacted sub-base is a sufficient foundation. Others will need an additional layer added during asphalt driveway preparation. This layer is known as the base. Whether or not the base layer is needed depends on the type of soil the sub-base is. If it is still soft after compacting, it may be necessary to add a base layer on top of the sub-base. This will provide strong and stable support for the asphalt. 

An experienced asphalt contractor can often tell if a base is necessary before the asphalt driveway preparation begins based on the soil common in your area. However, to be certain, contractors often do what is known as a “proof roll”. A dump truck is driven over every area of the sub-base. If the subgrade flexes more than an inch, those areas must be repaired. The soft soil is removed and replaced with a strong aggregate material. This repair process is known as undercutting.

Once the repairs are made, a base layer of crushed gravel, limestone, or Con-bit (a mixture of crushed concrete and asphalt) is put down. The type of base material used will again be determined by your contractor based on your region. Before the asphalt is installed, a binder layer of large aggregate and oil is put down to strengthen and support the asphalt.

Installing the Asphalt

Now that the asphalt driveway preparation is complete, it’s time to install your driveway. A top layer of fresh asphalt made up of small aggregate, sand, and oil is put down over the base. The asphalt is smoothed and compacted using a roller truck. The result is a new driveway that is both durable and attractive. 

Are you considering a new asphalt driveway in Ocean County, Monmouth County, or the surrounding areas? Give Certified Asphalt a call. We offer complete asphalt installation and maintenance services. We will be happy to come out and assess your situation and provide you with an accurate estimate. Contact us today!