LIVING ON THE EDGE! THE SINGLE MOST OVERLOOKED ASPECT OF A HARDSCAPE INSTALL
In this post, we’re going to highlight an accessory that receives little attention yet is critical to the success of every hardscape project: EDGING. Learn the importance of using the proper edge restraint, different options for edging, and how your base material will ultimately dictate which of these products to use.
Let’s be honest. Edge restraint is certainly not glamorous. In all actuality, it doesn’t even get seen after the project is complete. However, edge restraint is absolutely vital to a successful hardscape installation. All projects are subject to lateral forces and edge restraint is designed to protect the pavers or stones against these forces. While installing edging might seem like an unnecessary step in the process, it’s much easier to install it at the beginning than trying to go back and fix problems after-the-fact.
Edging should be used no matter the application type. In fact, the application type will ultimately determine which style of edging to use. Later in this post we’ll discuss edging options for traditional, permeable, overlay, and Gator Base applications … but first, let’s take a look at the 5 most common forms of edge restraint seen in the hardscape industry.
5 Most Common Edge Restraints
1. POURED CONCRETE
Poured concrete is the ultimate restraint. It’s usually installed 18” deep and 6” wide. However, this it’s not something typically seen on residential projects as it’s not cost effective nor is it aesthetically pleasing.
2. PRECAST CONCRETE
Precast concrete units provide great strength and a much better aesthetic than poured concrete. They can’t just be placed along the edge of the pavers though because the blocks will lean, ultimately allowing water to get in. It’s critical to mortar the blocks in place to prevent movement.
While we do see asphalt being used as an edge restraint in the field, it is NOT a great solution by any means. Asphalt will heat up and soften. It will also go through freeze/thaw cycles that will result in movement of the pavers.
Aluminum edging is durable, long lasting, and bendable to a degree. However, it kinks and can lead to stability issues down the road.
Plastic is a great option for edging. It’s very durable and can accommodate the typical radius shapes seen in many paver designs. Alliance offers 3 different types of plastic edge restraints. You can read more about them by clicking each of the styles listed below:
One of the most common mistakes we see in the field pertaining to the installation of edge restraint is not having the right base material. Edging needs to be installed on a solid, strong, and compacted surface. This means that if you don’t extend your base out past the edge of your project (aka creating space to install your edge restraint), you’ll be setting the job up for failure. For pedestrian applications we recommend extending the base a minimum of 6” past the perimeter of the installed pavers (12” for vehicular applications). Doing this will create a nice and solid foundation to securely affix the edging into.
Another common mistake we see involves the sand setting bed. It’s crucial to move the sand setting bed out of the way before installing your edge restraint! By not doing so, you’ll be affixing your edge into unstable material. The sand can also wash out. No matter what kind of edge restraint you opt for, be sure to move the sand setting bed out of the way prior to installing it.
A Note On Spikes
Plastic edging gets installed using spikes (unless you’re installing it on Gator Base, which would require the use of special Gator Screws). While shiny galvanized spikes sure look nice fresh out of the box, we always recommend using a non-galvanized spike. This is because the spikes will rust over time … and that’s a good thing! As the spikes rust they will expand and actually hold better in the ground and resist pulling out during freeze/thaw cycles. We recommend using a 10” spike for standard pedestrian applications and a 12” spike for vehicular applications. To answer the straight vs. spiral question … either works just fine as long as the spikes are non-galvanized!
Now that we’ve covered the different types of edging as well as preparing the base for a proper installation, let’s move on to edge restraints by project type.
EDGING FOR GATOR BASE
Gator Base has an excellent edge restraint system that involves affixing plastic edging directly into the Gator Base panels using special Gator Base Screws. The connection strength between the base, screw, and edging has been lab tested and proves to offer superior strength for a paver application. Installation is simple. The edging simply gets placed securely alongside the pavers and screws are used in every other hole. Each screw first gets hammered in so it’s flush and in contact with the plastic edging; then it can be screwed right into the base. To learn more about using edge restraint with Gator Base, click here.
EDGING FOR OPEN GRADED BASE
Open-graded base is becoming a much more popular installation method. However, it does present a unique challenge in terms of edging because spikes will not hold in clean stone. In fact, they can be pulled right out using very little effort. With that said, we recommend Xtreme Edge for open-graded or hybrid applications.
Xtreme Edge is fiber-reinforced and polymer-modified (so not your typical bag of concrete). It has a creamy consistency when mixed with water, giving it a nice workability. Since it’s modified with polymers, it also offers a degree of flexibility. Aside from hybrid applications, Xtreme Edge can be used for traditional, Gator Base, and overlay applications, too. It truly is a universal option for edge restraint. So how does it work?
When Xtreme Edge gets mixed with water, the fiber strands in it expand into a 3D lattice-work structure. This fiber matrix will ultimately minimize the potential of cracks and minimize the impact of cracks if they do occur.
Contractors often ask, “Can’t plastic be installed much faster?” Believe it or not, the workability of Xtreme is so incredible that it can actually be installed in the same amount of time as plastic!
EDGING FOR OVERLAYS
Drainage is the biggest consideration in an overlay application. Typically holes need to be drilled every 3-4’ on center to allow water to flow through the slab beneath the pavers. However, water must be able to flow off the sides of the project, too. With that said, improper installation of an edge restraint could potentially cause a dam and back up water.
If you’re using Xtreme Edge, weep straws can be embedded right into the concrete to allow for water flow off the sides of a project. If you’re gluing down a border course with a product like our XP Glue, be sure to create multiple lines of glue perpendicular to the border. This will allow water to flow through the little pathways you’ve created.
No matter what type of edging you choose, it needs to be installed properly. Don’t live on the edge. Take the time to do it right and avoid future failures.