Gravel driveways are very popular in some areas, and very hard to find in others. In many rural areas, gravel is the material of choice for both driveways and roadways. For homes, it is not uncommon to have gravel driveways leading to concrete garage floors. Gravel is much less expensive for long driveways than most other driveway materials, and it can last for generations with regular maintenance.
Gravel for Driveways
The term gravel can refer to any loose rock or stone that is larger than sand but smaller than cobble, which means it can range from about 1/10 inch to 2.5 inches in diameter. The gravel used for driveways, however, is typically a processed product, consisting of rocks, sand, and clay. This mixture has a major advantage over plain rocks in that it compacts much better to create a stable surface. Also, while coarse gravel or stone paving is designed to let water flow through it, most gravel driveways are designed to shed water, much like solid paving materials.
Maintaining a Gravel Driveway
Gravel driveways require regular maintenance, much more than concrete or asphalt driveways. Regular maintenance helps ensure optimal performance of a gravel driveway and helps prevent costly replacement. Depending on the local climate and how much traffic the driveway receives, gravel surfaces must be regraded once a year or more.
In the meantime, potholes and dips should be filled in to prevent them from getting larger and deeper. Potholes can be repaired with hand tools, but regrading requires heavy equipment, such as a tractor with a bucket and grader, to grade the surface and spread and compact fresh gravel.
One of the biggest drawbacks of a gravel driveway is that they are more difficult to plow or clear with a snowblower. You can't scrape the surface of gravel clean, lke you can with solid materials, without displacing the gravel. Even if you're careful, gravel becomes displaced over the course of a winter and must be replaced or moved back onto the driveway.
How Long Will a Gravel Driveway Last?
With proper care and maintenance, a gravel driveway can last up to 100 years. The beauty of gravel is that is can be repaired and replenished on an ongoing basis. By contrast, wear and damage to asphalt and concrete driveways is difficult to remedy, and replacement is often more cost-effective than extensive repairs. Gravel is also less vulnerable to damage from seasonal freeze-thaw cycles, or frost heave, which can cause significant cracking and settling in solid driveway materials.
How Much Does a Gravel Driveway Cost?
The cost of a gravel driveway can vary, from under $1 per square foot to over $3 per square foot. Even at the high end, however, it's still about the least expensive driveway you can build. One big factor in the discrepancy is how far the gravel has to be trucked. Another is the thickness of the driveway.
How Is a Gravel Driveway Built?
It is possible to create a rudimentary gravel driveway simply by having a dump truck unload some crushed rock where you want it. But the added cost of building a proper gravel driveway usually pays for itself many times over in the lifespan of the driveway.
The first step in building a gravel driveway is removing the topsoil and compacting the soil below. Then, an optional geotextile fabric is laid down, followed by a 4-inch layer of fist-sized rocks. On top of that goes a 4-inch layer of gravel roughly the size of golf balls, followed by a third layer of marble-sized gravel. Each layer is compacted thoroughly before the next layer is added. The driveway also is shaped with a crown at the center so that water flows off to either side.