By Julie Christensen
There are four materials commonly used for driveways – gravel, asphalt, concrete and pavers. Which one you choose will be based on your budget, your climate and conditions and the length of your driveway.
Gravel driveways are hands-down the most affordable option upfront. Asphalt driveways place second in cost, followed by cement and pavers. Although gravel driveways are the least expensive initially, they require the most maintenance long-term. Annual maintenance includes herbicide application and raking. You’ll need to add more gravel every two to four years, especially if you live in a snowy area or have a sloped driveway. The act of snow removal scrapes up a lot of gravel and deposits it on the sides of the road. You must rake the gravel annually to push it back in place.
If you’re willing to keep up with the maintenance, though, gravel is an affordable, durable material and makes an attractive driveway. Below, you’ll find everything you need to know about buying and installing gravel.
Which Gravel to Use?
When installing a gravel driveway, you’ll actually use three sizes of gravel. The first layer of gravel should consist of baseball size rocks, which are often called #3 stones. These rocks form a strong foundation for your driveway and ensure good drainage. This foundation layer also keeps the smaller rock from disappearing into the soil. You’ll install approximately a 4 inch layer of this rock.
On top of the base, you’ll install another 3 to 4 inches of golf ball-size rocks, often identified as #57 rocks. These smaller rocks form a similar function and help make the transition to the top layer.
The top layer of gravel consists of 4 inches of marble-size rocks. These rocks can vary in color from black to gray to rust, depending on the type of stone.
For each layer of gravel, you’ll want machine crushed stone, rather than round rock. These rocks have an angular, triangle shape and will lock together on the driveway. Round rock slips, creating an unstable surface. River rock, for example, is not appropriate for a driveway.
When choosing rock for the top layer, choose “traffic bound” or “dense-grade” gravel. This rock has rock dust and smaller pieces of rock added to the mixture. This dust forms a cement-like bond when compacted.
Top layer choices for gravel driveways might include crushed shale, limestone, granite and concrete, along with other types of gravel in various colors to meet your aesthetic needs.
Additional Tips for Gravel Driveways
Choosing the right gravel is important, but proper site preparation is even more vital. Before you lay any gravel, you must remove the top soil and use it somewhere else on your property. The topsoil contains lots of organic matter, which is great for growing plants, but creates a spongy, unstable subsurface for a driveway. Hardpan, the layer beneath topsoil, is, as the name implies, dense and hard. It creates a much better foundation for your driveway.
Some people apply an herbicide at this point, while others install landscaping fabric. Think about how you want to address weed control.
Proper grading is also critical to the success of your driveway. Gravel driveways need a crown so water drains quickly. A crown simply means that the middle of the driveway is slightly higher than the sides. If you live in an area that gets a lot of rain or snow, you should install ditches on either side of the driveway to carry water away.
Once you start laying the gravel, you must compact each layer with a rolling machine before applying the next layer. If all this seems like a lot of work, consider hiring a professional. Installing a gravel driveway is a big task for the average homeowner, but a professional with the right equipment can complete the job in a few days.
For more information on designing your gravel driveway, visit the following links:
Building an Enduring Driveway from This Old House
10 Popular Driveway Options to Welcome You Home by Bob Villa
What’s your favorite type of surface material for a gravel driveway? Leave a comment!
Julie Christensen learned about gardening on her grandfather’s farm and mother’s vegetable garden in southern Idaho. Today, she lives and gardens on the high plains of Colorado. When she’s not digging in the dirt, Julie writes about food, education, parenting and gardening.