Post 5 of 6- Stone
Welcome back to another edition of the Beginner’s Guide to Aggregate, Chatt Soil’s 6-part series aimed at providing you with a basic understanding of all things aggregate. This guide will help you save money by making informed decisions. Over the last few posts, we have discussed soil, gravel, and mulch; today we will jump into ROCKS (or Stone).
Definition
Let’s start with a simple definition provided by the USGS (United States Geological Survey)- “[a rock] is a solid aggregate [collection] of one or more minerals” [1]. Geologists classify rocks into three (3) main groups which we have defined below and provided examples of the most common types[2]–
- Igneous – formed through the cooling and solidification of magma
- Granite / Pumice / Basalt
- Sedimentary – formed at the earth’s surface by the accumulation of earlier rocks and minerals
- Shale / Limestone / sandstone
- Metamorphic – rocks which change after being subjected to various temperature/pressure(s)
- Marble / Soapstone / Serpentine
For our aggregate purposes, the rocks we will be discussing fall into the first two (2) classifications- Ingeous (granite) and Sedimentary (river rock).
Manufacturing / Production
All of the materials produced and provided by Chatt Soil are ‘harvested’ directly from the earth. Granite is mined in a quarry and processed into manageable pieces varying by product. River rock is dredged from the bottom of a river and mostly untouched[3].
Types & Uses
Surge Rock
Also known as ‘bull rock’ or ‘gabion’, can be produced from a variety of rock types. These rocks range in size from 2-4 inches, and are often used in retaining walls, erosion mitigation, and to create gabion baskets[4].
Gabion baskets are rectangular structures made with galvanized wire that is filled with stones. These are a very powerful asset in the erosion control toolbox! They are often used as a retaining wall, to fortify the banks of a channel, or to direct/change the flow of water to mitigate potential erosion damage.
Riprap
This product refers to a range of materials used to protect from erosion or loss of materials. These are placed along shorelines, on steep slopes, and/or along bridge foundations. These rocks are typically large, but can range from 4 inches to 2 feet. Chatt Soil can help you choose the right size for your project. Riprap is incredibly durable and long lasting, making it a great choice for any project.
[At this time ChattSoil does not stock this product, however, if you find yourself needing it do not hesitate to call us or fill out a special request form- we can likely find it for you!]
Natural (River Rock / Creek Rock 10”-24” and 3”-5”)
River and creek rock are smooth, round stones that have slight variations in earth-tone colors. This material has been shaped by the active movement of water over centuries. ChattSoil’s products are harvested locally–right here in Tennessee! The hardy material does not migrate much and will last for years with little to no attention.
Pea gravel
The ‘younger sibling’ of river rock, pea gravel is made up of small pieces of rock, usually around half an inch in size. After eons of rushing water flowing over them, the pebbles are smooth and round. This makes pea gravel fantastic for walkways, or as an aesthetic addition to trees and/or landscaping. Pea gravel looks beautiful on patios or garden beds.
Common Issues
While stone can provide an excellent addition to your landscaping both visually and functionally, there are a few issues/concerns that you should be aware of and avoid:
- Un-sturdy or non-level foundation. When applying stone, it is important that the ground is as flat as possible. While there are applications/situations where the material is added to sloping hills, a steep grade does make product loss more likely (for example, rocks washing away after a big storm). When building a retaining wall, it is very important to ensure your foundation is level so that your structure will be safe and long lasting.
- Poor / improper drainage. As a large and porous material, stone will not retain water. This means that all the rain will flow beneath it to the soil below. The result can be a soupy, muddy mess. To prevent this, make sure that you have considered water collection and have a mitigation solution incorporated into your project. If drainage issues are not accounted for, you may be subjecting yourself to the following issue:
- Erosion. When the underlying soil becomes saturated with water, it will deteriorate. This loss of support will decimate the functional capabilities and visual appeal of your stone. Mitigating efforts can include, but are not limited to, adding certain plants or incorporating landscaping fabric into your design.
Conclusion
Stone can be an amazing and beautiful addition to your landscape- providing a gorgeous visual appeal while helping with water issues. It is imperative that you select the correct stone that suits your situation, and that is why we are here! As always, if you need any help or have questions- contact the team at Chattsoil today!
Be sure to join us again next week as we conclude our 6-part Beginner’s Guide to Aggregate series. We will recap what we have discussed, and shine some light on the products we have not talked about yet, such as sand, pavers, and specialty offerings.
Thanks for reading, and happy landscaping!!
[1] https://www.usgs.gov/faqs/what-difference-between-rock-and-mineral
[2] https://www.amnh.org/exhibitions/permanent/planet-earth/how-do-we-read-the-rocks/three-types#:~:text=There%20are%20three%20kinds%20of,They%20accumulate%20in%20layers.
[3] https://sciencing.com/info-8441910-mining-techniques-sand-gravel.html
[4] https://gabionreviews.com/buyers-guide-for-gabion-baskets/
