by Julie Christensen
There are four materials commonly used for driveway surfaces – 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 a good choice for 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 base layer of gravel should consist stones the size of baseballs, which are often called #3 stones. This bottom layer of rock forms 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 creating a stable surface. 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.
The best type of gravel for the top layer of a gravel driveway includes crushed shale, limestone, granite and concrete. There are different types of gravel in various colors to have an aesthetic appeal.
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. For best results 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 for proper drainage.
Once you start laying the gravel, you must compact each layer with a rolling machine before applying the next layer to provide a solid foundation. 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 and can involve heavy machinery. A professional with the right equipment can complete the job in a few days.
Common Questions and Answers About Gravel Driveways
Can you add cement to a gravel driveway?
You can lay cement over a gravel driveway, even though it’s not normally recommended, as long as the gravel in the driveway is small enough. As long as most of the rocks in your gravel driveway are smaller than half an inch, they will work as an underlay for the cement. Refer to the American Standards for Testing and Materials specification ASTM C-94 to determine which types of cement will work best for you.
Can you paint a gravel driveway?
Yes, you can paint a gravel driveway. Either acrylic or oil-based paints are appropriate for painting a gravel driveway.
Can you walk on pea gravel?
You can walk on pea gravel, making it a suitable gravel type for driveways and walkways. You can even walk barefoot on pea gravel without it being too painful.
Do I need gravel under pavers?
It’s not required to have gravel underneath pavers, as pavers can also be laid over dirt or mortar. However, using gravel underneath pavers is recommended because gravel will prevent the stones from sinking and allow moisture to escape. Gravel is also flexible enough to prevent frost heaves.
Do you need a permit for a gravel driveway?
Depending on where you live and the circumstances of your particular driveway, you may need to apply for a permit before you begin working on adding your gravel driveway. Contact your city or its roads department for more information.
Does salt kill weeds in a driveway?
Spreading salt in your gravel driveway will kill any weeds that grow there, but it is a long-term treatment that will sterilize the ground for years. Rainfall can also spread the salt through the soil into areas where other plants are growing, killing them too. For this reason, salt treatments should be used as sparingly as possible.
How do I get rid of weeds and grass in my gravel driveway?
There are a few ways to remove weeds and grass from your gravel driveway that don’t involve pulling weeds by hand or using potentially harsh chemical treatments. As long as it’s not a drought and the weather isn’t especially hot and dry, you can use a propane torch to burn off grass and weeds in your gravel driveway. Or apply a treatment made of a spray bottle filled with white vinegar and a few drops of dish soap, spraying onto unwanted weeds or grass in your gravel driveway. If your driveway is near the kitchen in your house, it’s practical to pour boiling hot water over your driveway to kill any weeds, though this solution takes more time and energy the larger your driveway is.
How do I keep my gravel driveway from sinking?
The best option is to occasionally maintain your driveway by raking the surface and adding some new rock to keep things level. This will prevent it from sinking in the first place. Once sinking has occurred, you can also take steps to correct it. When your gravel driveway has sunk four or five inches, it’s time to fix it before water soaking into the soil at the lowest points ruins the driveway, causing larger holes and ruts.
Driveways require a few structural elements to prevent sinking and the formation of low spots. First, it needs enough of a base of gravel for there to be plenty to keep the driveway filled. A driveway also needs a proper crown and high shoulders to keep sinking to a minimum and keep it from losing stones due to water erosion. Ditches alongside the driveway on both sides help keep water erosion at bay, too, and must be kept empty and clean to do their job properly.
How do you keep a gravel driveway in the winter?
To get your gravel driveway ready for winter, first repair any potholes by filling them with fresh gravel. Then grade the surface using a tractor’s grader blade attachment to create a crown in the center of the driveway. The crown should measure one inch per three or four feet of driveway width. Use the blade of the tractor to pull gravel from the sides back to the center, adding fresh material if needed. You’ll probably need to add new gravel every two to four years. Then prepare for the snowy season by making sure you have snow removal tools, such as a snowblower or snow shovel, at the ready.
How do you keep grass from growing in gravel?
Spreading salt in your gravel driveway will kill weeds and keep the driveway free of them for years. However, it’s a long-term solution, and the salt can also spread to nearby plants as water moves through the soil, killing those plants as well as weeds in your gravel driveway. For these reasons, use salt treatments sparingly. A spray bottle full of vinegar mixed with a few drops of dish soap will also kill weeds where it’s applied. If your driveway isn’t too big and is near your kitchen, you can splash boiling water on the gravel to kill any plants growing there.
How do you keep gravel in driveway?
Once or twice a year, you should use a tractor with a grading blade to move gravel from the sides of the driveway toward the center to re-establish the crown. There should be one inch of crown per three or four feet of your driveway’s width. You can also add borders, such as brick pavers, railroad ties, bricks or stones, or wood pieces.
How do you maintain a gravel driveway?
You’ll need to add more gravel to the driveway every two or three years. Once or twice a year, use a tractor with a grading blade to renew the crown by pulling gravel from the sides back to the center of the driveway. You need about one inch of crown per three or four feet of your driveway’s width. Rake the driveway on a consistent basis to remove sticks, leaves, and other materials. If low patches appear and begin to collect water when it rains, fill them in with more gravel, along with any potholes that develop.
How do you plow a gravel driveway?
Set the snowplow up with shoes set about half an inch above the ground. First plow the middle of the driveway, then work up and down alongside your initial line, rolling snow off to the side. Avoid creating large banks on the sides of the driveway, which can become harder to move with each snowfall. Leave about an inch of snow on the driveway; it will provide a good driving surface and prevent the plow from disturbing the gravel. Your tires will still get plenty of traction from the gravel with an inch of snow on top.
How long does a gravel driveway last?
The question of driveway durability comes down to how well that driveway is maintained. When properly cared for, a gravel driveway can last decades. Make sure to add new gravel as needed every two to four years. Once or twice a year, you should use a tractor with a grading blade to move gravel from the sides up to the center of the driveway to create a crown. The crown should be one inch for every three or four feet of driveway width.
How many inches deep should a gravel driveway be?
Use two or three layers of gravel to create a gravel layer that’s four to six inches thick when building a gravel driveway.
How many inches of gravel will you need for a concrete slab?
Your total amount of gravel underneath a concrete slab should be eight inches. Four inches of gravel will act as the base, and four inches will be used in the concrete slab.
How many square feet does a ton of gravel cover?
How far your gravel will go depends on how deep you are planning to pour it. A one-inch layer of gravel covers 240 square feet, while a ton spread at a depth of three inches covers eighty feet. Plan to use about a ton for every 70 square feet.
How often should you re gravel a driveway?
You’ll probably need to add new gravel every two to four years or so when maintaining your gravel driveway. You should also re-grade the driveway with a tractor and a grading blade once or twice a year to reset the crown by moving gravel from the sides to the center. Expect about one inch of crown per three or four feet of your driveway’s width.
How thick should my gravel driveway be?
Gravel driveways look best and last longest when they’re at least four to six inches deep.
Is asphalt cheaper than gravel?
Asphalt is cheaper than concrete, but gravel is the cheapest driveway option.
Is gravel cheaper than concrete?
Gravel driveways are generally cheaper than concrete driveways.
Is pea gravel good for driveways?
Pea gravel is relatively inexpensive and easy to work with, and it’s commonly used to create gravel driveways. Pea gravel is also a durable, low-maintenance driveway material.
Should you salt a gravel driveway?
Salting a gravel driveway will kill grass and weeds growing there and keep the driveway clear of plants for several years. However, the salts can also spread through the soil due to rainfall and damage other plants growing nearby. For these reasons, salt should be used carefully and sparingly on gravel driveways.
What can I put on my driveway to keep dust down?
Moistening the top of your gravel driveway with plain water will help keep dust to a minimum. Apply some water with your garden hose or sprinkler system every couple of days.Using salt or binding materials is more effective and permanent, but they can also spread through the soil as rain falls to poison nearby plant life. Salt and binder treatments should be used carefully and sparingly for these reasons.
What causes potholes in gravel driveways?
Potholes develop in low spots because of water trapped under the surface of your gravel driveway. Maintaining a “crown” in your driveway of an inch of height in the center per three or four feet of your driveway’s width can help with drainage, as can trenches or ditches installed alongside the driveway. To fill a pothole, first check the hole for any large stones or other debris and remove it from the driveway. You may need to use a spade or other tool to make the sides of the hole even. Then fill it with gravel, compacting it and adding in layers until the hole is full.
What is self-binding gravel?
Self-binding gravel settles to create a compact surface for walking and driving without the need for binding materials.
What is the cheapest driveway surface?
Asphalt is cheaper than concrete when it comes to building a driveway, but gravel is the cheapest option of all.
What kind of gravel do you put under concrete?
Use a layer of pea gravel under concrete that’s eight to 12 inches thick.
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.