Post 3 of 6: Gravel Basics

Welcome back!! In our first post we introduced you to the awesome world of aggregate; digging in a bit further for Post #2 we talked all things SOIL / DIRT. Now it is time to roll into the world of rocks! After a quick definition and discussing the manufacturing/production process we will look at each type of gravel specifically to provide a holistic overview of the category.


Fairly straight-forward, gravel is defined as “small pieces of rocks, or pebbles, that are larger than a grain of sand”. Gravel products come in a wide range of shapes and sizes, each functioning in a variety of unique and practical ways. In addition to providing a working surface to dirt roads and driveways, gravel is often mixed in to provide structure to cement and asphalt.  

Types of Gravel 

There are two distinct categories of gravel: crushed stone and natural gravel: 

Crushed stone is exactly what it sounds like- large boulders, or chunks, of rock (often granite) are harvested from the earth at a quarry then processed through the ‘crusher’ to yield smaller more manageable material.   

Natural gravel refers to the materials that are formed/shaped by the earth naturally over centuries of erosion and water flow. Examples include- river rock and pea gravel (pebbles).  


Due to the smooth and rounded shape of natural gravel it tends to ‘migrate’ out of an area unless it confined by a solid border boundary. The more weight that the gravel supports the more migration that occurs. Conversely, crushed stone, with its irregular shape(s) and rough texture, will interlock with the other pieces, allowing it to withstand weight and pressure while remaining mostly in place.  

Types of Gravel 

While there are almost countless variations of gravel (shapes, sizes, colors, etc.) below is an overview of the products provided by the team at Chatt Soil

Crusher Run  

A common and widely used base layer for construction projects, driveways, and thoroughfares. This material contains silt, and a mixture of 1/4” minus and #57 gravel to promote water drainage and provide a foundation for a wide range of needs.   

¼” Minus  

Essentially the base component of crusher run gravel, this material is compactable and versatile; providing stability for pathways and pavers.   

#57 Gravel  

This gravel is a mixture of ¾” and ½” gravel, excellent for French drains, trenches, or other water mitigation functions. Additional applications include parking pads and underground pipe installation.   

#4 Gravel  

The ‘big brother’ to the #57 Gravel, #4 is comprised of larger pieces of rock ranging from ¾” to 1 ½” – making it a fantastic solution for heavy vehicles and erosion problems. Storing a tractor or large RV? This is the product for you.   

Common Applications 

As we have mentioned, gravel is the support system for a gamut of construction, landscaping, and project purposes. Driveways, paths, and parking lots are likely the most common usages that everyone is familiar with. Another fantastic application of gravel is water drainage. Due to its permeable nature, gravel is fantastic at mitigating water retention issues; from French drains and drainage ditches, gravel provides a viable surface foundation while displacing the water and preventing its collection. While less renowned, gravel has emerged over the last few decades as a solid solution for landscaping and décor functions. Its aesthetic appeal makes it fantastic for boarder material, edging, or as an accent piece to improve the appearance of landscaping and gardens.  


While the world of gravel is vast and formidable, it should not feel overwhelming or unapproachable. If you ever have any questions, you can always reach out to the Chatt Soil team for help and guidance. Make sure you check back in with us next week as we jump into the woods and talk all things MULCH!! Thanks for reading! We hope that this was informative and helpful. See you next week!!