Designed for cars and medium-weight trucks, asphalt drive installation materials are similar to that used on roads, only in a thinner, less expensive mix of rock and petroleum products. An asphalt drive gives property a finished look.
There are two types of asphalt for drives. One drive installation comes from a hot mixture of aggregate rocks of different sizes held together with a petroleum-based binder. Special machines compact the hot mix asphalt (HMA) to the proper density and thickness for a driveway installation. The other type of asphalt mix uses a cold mixture of aggregate and binder. Unfortunately, this type doesn’t hold up well in warm climates. As the temperatures warm, the binder softens around the aggregate and the surface develops soft spots.
No matter what type of asphalt you choose, or how thick you put it on the drive, there must be a solid base under the drive for it to last. Many builders recommend a compacted base of rock with a depth no less than 20 cm (8 inches). Compacting the asphalt during installation is important as well, or the surface may give way during hot weather. The ground surrounding the drive should drain well. The drive should have a slope of at least 6 mm (1/4 inch) per 30 cm (1 foot).
The amount of crushed rock base can affect the depth of asphalt required, with thicker bases requiring less asphalt. Consider the size and kind of expansion joints necessary between the public pavement and the private asphalt drive.
While it’s possible to put a sealer on an asphalt drive, installers typically recommend waiting at least one year before doing so. Unless the asphalt is showing signs of separating or cracking, sealing may not be necessary at all.
Itinerant driveway construction crews may pass through your neighbourhood wanting to put in a new asphalt driveway, or seal and repair the existing driveway. They often do substandard work and use below-grade asphalt materials. If the driveway needs repairs, hire a reputable local contractor to do the job.