Variety is the spice of more than life. It’s also an inherent property of other things that come from the Earth, and gravel is no exception. One important type of difference when it comes to gravel is its size and whether it includes “minus.” Minus is the name for the fine particles that are included with certain gravel types, and in some installations, it is an essential aspect of the material.
Gravel in Portland, Oregon that comes with minus is used for base layers of driveways, walkways, roads, sidewalks, and even retaining walls. The larger pieces provide strength, while the minus compacts to form the hard layer that is needed to serve as a firm foundation that will resist ruts and allow solid elements to remain flat for a long period of time. This type of gravel is usually gray and not too great to look at on its own. Therefore, it is typically covered with pavers, tiles, concrete, asphalt, or even other types of gravel. Minus gravel from stores like Best Buy in Town comes in two sizes: 1/4-inch and 3/4-inch. The smaller variety compacts a bit more tightly than the larger, though either one will do the job in most cases.
Clean crushed rock is gravel without the fine “minus” elements. It doesn’t compact well, but has excellent drainage. This type of gravel is typically used as a top layer for decorative walkways, driveways, or other installations where appearances are important. It can also be used as a base layer for patios. Clean rock is available in many colors. The basic version is a shade of gray, but varieties that are sold specifically as decorative rock come in white, salt-and-pepper, and an entire rainbow of other shades ranging from red to terra cotta. This makes it easy to put a beautiful top layer on a foundation of minus gravel.
The shapes of clean rock also vary. While jagged crushed rock is the most common, it’s also possible to get smooth pea gravel or larger smooth rocks. The larger variety appears to have been rounded by natural river action rather than a machine, so it’s great for installations that need a natural look.