Gravel driveways are a popular choice among homeowners and for good reason. They’re relatively inexpensive, they can be installed without hiring a professional, and they look great – provided they are constructed properly. In this article we will cover a couple related and common questions we see from DIY homeowners about their gravel driveways: How to keep gravel in place and how to stop gravel from sinking into the ground.
Both of these questions are answered in our “How to Build a Gravel Driveway” post so if you need a step-by-step guide, please check out our article here. This article will answer specifically, how to stabilize a gravel driveway.
Background
These questions can mean different things to different people in different situations and it all depends on how your gravel driveway was built. Because of this, it’s important to understand how a properly built gravel driveway should be constructed.
A gravel driveway should consist of at least two different gravels, placed in at least 3 separate layers, underlain by a layer of geotextile, and depending on the soil conditions, a layer of geogrid or gravel grid.
The surface gravel should be a small diameter crushed gravel, around 20 mm (3/4 inch) maximum size. If you want to check your driveway to see if yours fits the bill you can take a ruler and look around for the largest pieces of gravel you can find in your driveway surface and measure their sizes. Aside from these larger pieces, the rest of the gravel should be pieces of gravel to that size (20 mm to 3/4 inch), all the way down to sand.
Your base layers should consist of an 80 mm (3 inch) crushed gravel. It is almost the same as the 20 mm (3/4 inch) crushed gravel, except the largest pieces are now 80 mm (3 inch).
It’s important that the gravel be crushed so that the faces of the gravel are angular and not round. The finer materials also fill the voids between the larger gravel pieces. Both of these facts allow the gravel to interlock with each other and form a more solid surface for you to drive on. Gravel without fines and without angular faces will easily rut and roll around like ball bearings. Bad news for your driveway.
1. Keeping Gravel In Place
Now, if you’ve built your driveway with the materials as described above (and in our guide) and properly compacted them – you’re probably not having major issues. If you’re having issues with gravel moving out of place it’s likely that you’re on a hill, your gravel is rounded (not crushed), or the gravel does not have the smaller sand-sized rock fragments to fill all the void spaces.
Building a gravel driveway on a hill is very difficult and gravel being displaced will always be an issue, your best bet here is to save up and pave the driveway. Sorry.
However, if you’ve built your driveway with the wrong gravel and need to redo it, you won’t need to discard all the gravel you’ve already got. But you will need to buy something called gravel grid (also known as ground grid or geocells) and remove the gravel so that you can install the geocells.
Geocell design varies from company to company, but basically they work by providing a strong and reliable structure for your gravel through the principle of “cellular confinement”. Research into geocells has shown that a geocell reinforced gravel layer has capacity/strength equivalent to an unreinforced gravel layer that is twice as thick. It also has the added benefit of not allowing gravel to move as easily. It’s important to note that not all geocells will function on a hill.
To install geocells you’ll need to remove the existing gravel driveway first, then install the geocells according to the manufacturers instructions. While it does vary from product to product, it is recommended that you use geocells that are at least 4″ thick.
| Manufacturer | Geocell Product Name |
|---|---|
| Standardartpark | Geo GroundGrid |
| Presto Geosystems | GEOWEB |
| TrueGrid | Pro Lite |
| DeWitt | Dupont GroundGrid |
| Nilex | Envirogrid |
2. Stop Gravel From Sinking Into The Ground
This is another problem that is covered in our step by step gravel driveway guide. Thankfully it’s a cheaper fix than geocells, but it still requires that you remove your gravel driveway and reinstall it.
Geotextile works by providing a permeable barrier between your driveway and the soil below it. It will keep your expensive gravels free of contamination and allow them to drain water easily. Without geotextile, your driveway slowly sinks into the soil below it and becomes plugged with undesirable soils.
Simply, you’ll just need to remove your driveway and lay down a layer of geotextile. If you want to be safe, you should also place a layer of geogrid. Once you’ve placed the geotextile (and grid if you’ve chosen to), you’ll just need to rebuild the gravel driveway. Check out our guide for a step by step walkthrough.
It’s important that you don’t use landscape fabric or weed barrier. You need to use a non woven geotextile meant for construction – not landscaping.
