Crushed Stone Driveways
By Phil's Excavating Bellingham MA
Crushed stone driveways, sometimes referred to as gravel driveways, are a beautiful and low cost driveway that adds a folksy, comfortable look to your house. It offers excellent drainage putting water into the ground and the water table, not the street. Unlike a concrete or asphalt driveway, frost heaves are no problem for crushed stone, just rake the stones back into place.
However, many people use the wrong type of stone causing themselves unnecessary problems. Crushed stones are usually pieces of granite or limestone that were broken up by a crusher. This is important because the crusher puts angles and points on the stones so that they fit together in a driveway when compressed and will not be washed away by rain or from car tires.
Driveways are usually made from 3/4" crushed stone
3/4" stones are large enough to stay in place and not be disturbed by car tires and rain, but not so large that they damage tires. Some driveways are made from 1/2" crushed stone which is better suited to a walkway. Even on a walkway, the walk should not be on much of a slope because a heavy rain will wash 1/2" stones away.
Pea stones, a rounded 1/2" stone are even worse for a driveway. The round sides allow them to be spread all around by tires or people walking. They are best suited to garden paths where people rarely walk but an attractive stone is desired.
Crusher run is a mixture of stone dust and various sizes of crushed stone. As the name implies, it's the runoff from the crusher. For a simple driveway, it can be used in place of stones and is usually cheaper, but not as good looking. Crusher run can also be used as a base for the driveway instead of gravel.
Types of crushed stone
Granite is an excellent crushed stone to use for driveways. Crushed limestone is frequently used but Mexican tan and Bahama white limestone have a tendency to give off a dust that gets tracked into the house and car especially when wet from rain. Some people use crushed cement, but it often has pieces of junk in it such as nails and rebar. Cement is also porous and slowly breaks down in the rain, leaving a dusty or muddy mess.
Installing a crushed stone driveway
When putting in a crushed stone driveway, dig out the existing soil until you reach sand or some other substance that won't turn to mud in the rain. Then, put in at least 6" of gravel for a base. More gravel may be needed if you had to dig deep to get rid of muddy soil. Gravel is a natural mixture of sand and stone that adds drainage and will compact down). (Some people use 1 1/2" stone for the base instead of gravel.) Then add at least 5" or 6" of 3/4" crushed stone. This will give you a long lasting surface. It's best to use a compactor to force the stones evenly in place but driving over uncompacted stones will eventually pack them down.
The driveways can be edged with landscaping ties to help keep the stones from spreading out.
How much stone will you need?
To determine how much stone your driveway will need, find the square footage of the driveway (length times width), multiply that figure by the depth of the stone in feet ( a 6" depth will therefore be 1/2 foot). Divide the total by 27 to give you the number of cubic yards needed. Crushed stone is often sold by the cubic yard. For example a drive way 12 feet wide and 2o' long with 6 inches of stone will be calculated as follows: 12 X 20 X 1/2 = 120. 120 divided by 27 gives about 4 1/2 cubic yards of stone.
Sometimes stone is sold by weight. While weight can vary according to the size and type of stone, crushed stone is around 2700 pounds per cubic yard. Therefore the 4 1/2 yards of stone in the example above will need a little more than 12,000 pounds of stone or 6 tons.
Currently in Massachusetts 3/4" crushed stone costs about $38.00 per cubic yard, excluding delivery costs.
Caring for a crushed stone driveway
Weeds often grow in the crushed stone driveway but can be contained by occasionally spraying Roundup on the weeds. White vinegar also kills weeds and is better for the environment.
Snow removal can be a bit of a problem. If the snow is light it can be blown off with a leaf blower. Heavier snow requires raising a plow, snow blower or shovel an inch to avoid hitting the stones.
Occasionally crushed stone driveways need some new stones to be kept in tip top shape. Just buy some more stones and rake them in place. It's a lot easier and cheaper than tearing up a cracked concrete or asphalt driveway and installing a new driveway.
If you are within 15 miles of Bellingham MA and are considering a gravel or crushed stone driveway see our web page. Or, you may contact Phil's Excavating for a review of your property and a driveway quote.