Gravel driveways are one of the most common choices for Western Washington rural and suburban properties, where the average driveway lengths are many times the length of a city driveway. In many cases, concrete or asphalt surfacing can be cost prohibitive for a lengthy driveway. Gravel is a good choice as it is relatively cost effective, is durable and can be manipulated when necessary.
Material terminology is important so you know what to expect and what to order when you need to.
- Aggregate size refers to the size of the rock material, so a 5/8 washed rock order will be composed of rock material approximate 5/8” in size.
- Minus material refers to the fines in compactable gravel mixes. Fines are essentially rubble debris that occurs during the crushing process. Fines allow for gravel material to compact. One of the most common compactable gravel is 5/8 minus material, so it will be composed of aggregates 5/8” and smaller and fines.
- Washed rock refers to rock material of a specific size that has been washed and is clear of dirt and debris. Washed rock contains no fines or minus materials and so has minimal compaction value. Most washed rock refers to crushed rock and is commonly used in rockscapes for landscaping.
- River Rock refers to smooth washed rock, as you would find on a river bed. River rock comes on various sizes and also numerous colors and shapes, but generally most river rock has rounded edges and smooth surfaces.
- Pea gravel refers to small diameter washed rock. Pea gravel is commonly available in ¼”3/8” in diameter. Pea gravel has very little compaction value and offers a soft, slushy feel under your feet and is commonly used for entrances, walkways and entertainment areas.
Typical driveway construction
A typical driveway construction depends on the structure of the area where the driveway is planned to be located. In some situations where the ground is solid and compacted with proper sloping and no drainage issues, the area is first graded, then a layer of compactable gravel can be laid along the length of the driveway. Once laid, it can be graded to create a uniform layer of gravel along the length of the driveway. The gravel can then be compacted if desired. If desired, a driveway fabric can be laid out before the compactable gravel to prevent grass and weeds from establishing in the driveway.
In most cases however, especially new builds or new driveway construction will likely have softer soils and a base course of non-compactable larger material (1 ¼”-3”) can be laid first to provide a structural foundation for the driveway, as well as allowing drainage. The base course is graded out to be uniform, then a layer of compactable gravel is laid over the base course. Final grading will create a uniform level along the length of the driveway.
Graystone Tractor Service driveway services can help you construct new driveways as well as repair and maintain existing ones including grading. Call / text us at (360) 542-6460 or fill out our free estimate request form.