There are many benefits of using Geo Cellular Confinement Systems (GCCS) to the project owner and/or contractor. Less gravel is used with this system, which means less gravel to truck to the job site (less carbon footprint), and, therefore mining of the gravel, which is a more sustainable approach to construction. So, instead of using 18 inches of gravel underneath, you now use 12 inches of gravel. Plus, the GCCS system performs as good as having 18 or 20” of gravel underneath.
The benefits are for both wet setting or dry setting because both scenarios use gravel as sub-base. Particularly, important for dry-set because dry-set has two ways of failure. One, water washing away under the pavers and creating voids. The second type of failure is pavers “walking” off the edge or spreading out because the gravel is heaving and setting back down, repeatedly during freeze/thaw cycles. It pushes up and settles back down. Each time those pavers have a propensity to spread apart each time, maybe a 1/100th of an inch, and when you have 40 freeze/thaw cycles in a year, it adds up. It is called creep or spreading by having a confined gravel system underneath.
Problems can be mitigated with GCCS to about 90% of the time. With a concrete pad, the whole pad isn’t going to creep, but it can crack from heaving. So, having the cellular confinement below the slab mitigates the chance of it cracking. When the gravel is confined, it eliminates 90% of the chance of the slab from heaving. Now, if you have a pool of water underneath and didn’t plan the water escape route, you have a cistern underneath your project installation. Of course, you must excavate and dig, as part of the installation, but you must plan where the water is going to go. Once it rains, it’s going to go underneath and lay in a puddle, especially when you have ground that doesn’t percolate well, and that’s a whole other technical issue If you have good, percolating soil like sandy soils percolate, it’s called percolate well, which means the water goes through it. Well, if you have clay soils underneath, the water doesn’t go through it. It just doesn’t. It just sits there. And then when it sits there, it freezes. What happens?
Frozen water expands, so you’re going to have heaving and then you’re going to have your slab cracking or you’re going to have the pavers going up and down, up and down, up and down and moving, and then the water goes down and washes out underneath them. So that’s why Geo cellular confinement systems are important for exterior installations and 100% important for dry-set installations.