Building a Gravel Driveway: 5 Mistakes to Avoid
You can build a gravel driveway that will cost less than a paved driveway but last just as long. If you don't mind the extra maintenance required, you’ll find that gravel is a very effective material. Keep in mind that for the novice do-it-yourselfer, there are certain mistakes you will need to avoid, so consider the following as you plan and construct your own gravel driveway.
1. Spongy Bed
Don't even think of spreading gravel until you've prepared the ground where you'll be laying it. Building a driveway on soft soil that has roots, leaves, grass, weeds, and other type of debris creates a spongy surface that asks for trouble. You'll need to remove all topsoil, and strip the soil down to hard rock so you'll have a more dependable bed. Remove your topsoil and pile it somewhere nearby where you'll be able to use it later.
2. Poor Drainage
A driveway that is not leveled for proper drainage will eventually be damaged by eroding water. It can even become a mud hole when silt from below is forced up into the gravel. This fine silt can cause the gravel pieces to lose their friction and begin to separate and weaken. Under these conditions, your gravel will soon become buried in a quagmire. To keep this from happening, install a layer of geotextile fabric between your subsoil and the bottom layer of gravel.
3. Failure to Use Side Forms
Gravel that is spread on a surface without secure wooden forms or edges will eventually be squeezed outward from the driveway and will scatter on adjacent surfaces such as sidewalks, lawns, patios, or even a nearby street. Another possibility is to lay a retaining wall of brick or concrete block, rather than wood, to prevent your gravel from spreading beyond the boundaries of the driveway.
4. Using Gravel of the Wrong Size and Shape
Unless your base layer of gravel pieces are at least three inches to four inches in diameter, you can expect them to shift and sink when weight from vehicles is placed on top. These pieces should be angular and have sharp edges. Round-edged pieces are unable to lock in place with adjacent pieces, but sharp-edged pieces can be almost as solid as a single large rock. Pieces on the final, top layer should be no larger than a golf ball. The total thickness of your driveway with layers of various-sized gravel pieces should be about 12 inches.
5. Base Layers Not Compacted
Your driveway should be composed of various layers of gravel, but unless each layer is compacted, the driveway will not retain its shape. Each layer should be about four inches thick and should have gravel pieces smaller than those of the layer below it. Compact individual layers as you lay them down by tamping with a machine or hand-operated roller.