Geogrid Basics: What to Know for Retaining Walls & Hardscaping
If you work in the hardscaping industry or plan to construct a retaining wall, you’ll likely come across recommendations for using a geogrid retaining wall.
You may be wondering — What is geogrid? What do I need to know to install it?
In this article, we'll discuss how it works, different types of geogrid, and the use of geogrid for retaining walls.
What is Geogrid?
Geogrid is a net-like material used to reinforce and stabilize soil and slopes. It is constructed from plastic or other durable materials that have a long lifespan. Stronger than the soil surrounding it, Geogrid provides a stable base for retaining wall work that exceeds three feet in height. Stabilizing and reinforcing the soil behind a retaining wall can prevent wall failure and reduce soil movement.
How Geogrid Works
Geogrid works by tying into the soil matrix and providing additional strength, helping to stabilize and prevent soil from shifting. As the geogrid is stronger than the soil surrounding it, it gives added support and reinforces the soil structure.
Geogrid is designed to distribute weight across a larger area and provide stability to soil, making it stronger and enabling the construction of a solid wall structure.
Excess water in the soil reduces stability and can result in landslides, including the soil behind a retaining wall. This exerts additional pressure on the retaining wall, which can lead to its failure. However, incorporating a geogrid increases soil stability prevents unwanted soil movement, and eliminates the excess pressure on the retaining wall.
Types of Geogrid
Geogrids come in three distinct types: uniaxial, biaxial, and triaxial. Uniaxial geogrids have greater control over motion in one direction than in another, while biaxial geogrids have control in two directions. Lastly, triaxial geogrids are used for soils that require significant load-bearing capacity.
An uniaxial geogrid provides the most stable soil in a single direction — making it the best option for tall retaining walls. To achieve the best result, lay the heavier strands of the geogrid perpendicular to the blocks you are placing. This will prevent any motion towards the blocks.
However, if you're dealing with high-pressure locations such as a permeable driveway, you'll probably need to use a triaxial geogrid. This choice can distribute the point load in different directions and keep everything in place.
How To Install Geogrid for Retaining Walls
Having the right tools at hand is essential when starting your retaining wall project. You'll need cutting tools, grading tools, clamp tools, and compaction tools to get started. First, you need to remove organic materials from the top of the subsoil. Then, compact the subsoil and lay the soil stabilization fabric. Next, add gravel and compact it until it reaches a density of 98% proctor. Make sure to level the base material with the Wall Screed. Proper drainage behind the retaining wall is crucial to prevent any water in the soil from causing erosion problems.
Once you lay the first row of blocks, backfill with compacted gravel and then add appropriate drainage behind the wall. Make sure to set the first layer of geogrid at engineer specifications and check for level ground. For each layer of geogrid, you will repeat this pattern of laying blocks, backfilling, and laying geogrid. Every layer of geogrid should follow engineer specifications for the retaining wall.
Benefits of Using Geogrid
If you're looking for a way to take your retaining wall to new heights and extend the lifespan and performance of your retaining wall, geogrid is an excellent option. Not only is it a cost-effective solution, but it also provides exceptional value to hardscaping professionals.
In addition, Geogrids ensure that your retaining wall will continue to perform at an optimal level for many years. Thanks to its unique properties, geogrid is a reliable and durable solution that can help you avoid costly repairs and replacements down the line.
To ensure that your retaining wall stays in top-notch condition, consider using geogrid to improve its longevity and performance.
The Effectiveness and Versatility of Geogrid
Geogrid is an ideal solution when it comes to reinforcing retaining walls and preventing property damage from collapsing. While various types of geogrid are on the market, uniaxial or biaxial are generally suitable for most hardscaping needs. By incorporating this versatile and practical construction material, you can build longevity into all of your hardscaping projects and ensure that they stand the test of time.
Need some assistance? Check out our how-to guide for installing geogrids: