Gravel stabiliser

Frequently asked questions

How do you install a gravel stabiliser?

Installation takes seven steps. The depth of the sub-base depends on use: pedestrian or vehicle traffic.

1. Excavation: dig out the area and always remove the topsoil down to load-bearing ground.
2. Edging: install the perimeter edging: it should stand about 2 cm above the top of the grids to contain the gravel.
3. Sub-base (vehicle areas only): lay at least 25 cm of 0/31.5 or 0/40 crushed aggregate (limestone, porphyry or crushed concrete), in layers of 20 cm maximum compacted with a plate compactor. Avoid crushed brick, which breaks down.
4. Bedding layer: spread a levelling layer of fine grit or crushed sand (0/4, 1/3 or 2/4 mm), compacted and levelled: 5 cm under a vehicle area, up to 15 cm for pedestrian use without a sub-base.
5. Laying the grids: unroll the grids in a staggered pattern (offset joints), overlapping the geotextile. Cut with an angle grinder.
6. Filling: pour the gravel and spread it with a rake and squeegee without compacting it, leaving 1 to 2 cm above the cells. Never drive on unfilled grids.
7. Check: after the first few passes, level and top up where necessary. The surface will not move after that.

What type of gravel for a stabiliser grid?

Four criteria matter: grain size, shape, hardness and colour.

• Grain size: never use fines below 4 mm (they stick to soles and tyres and clog the drainage). Use 4/8 mm for pedestrian use and 8/16 mm as soon as vehicles drive on it. Stay below 16 mm with ECCOgravel (up to 25 mm with Multidal).
• Shape: rounded gravel (pebbles) is softer underfoot, ideal for a patio or garden path. Angular crushed gravel locks together better and moves less: it is the right choice for a driveway.
• Hardness: choose a hard, low-porosity stone (granite, porphyry, quartz…). Soft stones eventually crumble, create dust, turn green in the shade and lose their permeability.
• Colour: choose a white grid under light gravel and a black or grey grid under dark gravel, so that it stays invisible.

How much gravel per m2?

You need to fill the cells and leave 1 to 2 cm of gravel above the grid. Allow approximately:

• 65 kg/m² with a 3 cm grid (ECCOgravel 30, Multidal);
• 80 kg/m² with a 4 cm grid (ECCOgravel 40).

Example: a 25 m² driveway in ECCOgravel 40 needs about 25 × 80 = 2 000 kg, i.e. 2 one-tonne bulk bags. Add the bedding layer (5 cm of grit is about 80 kg/m²) and, for a vehicle area, the sub-base aggregate.

How do you build a path, yard or car park in crushed stone?

The structure is the same, only the thickness changes with the load:

• Footpath or patio: dig out about 15 to 20 cm, install the edging, lay a compacted bedding layer of up to 15 cm, then the 3 cm grid and 4/8 mm gravel.
• Yard or driveway: dig out about 35 to 40 cm, lay at least 25 cm of compacted 0/31.5 aggregate, 5 cm of bedding layer, a 4 cm grid and 8/16 mm crushed stone.
• Car park: same principle as the yard, with markers to mark out the spaces (8 to 10 markers per space). On a car park with heavy, fast traffic (over 10 km/h), build the driving lanes in a bound material and keep the stabilised gravel for the parking spaces.

In every case, it is the cells that stop the crushed stone from migrating: without them, it ends up forming ruts and hollows.

What type of gravel for a driveway?

Choose 8/16 mm crushed gravel from hard stone. Its sharp edges interlock and resist wheels turning, unlike rounded pebbles that slip away under tyres. Avoid soft limestone and mixes with fines (0/6, 0/20…), which break down and hold water. Combine it with a 4 cm grid (ECCOgravel 40), which spreads the load better onto the sub-base.

How do you keep gravel in place on a slope?

On a slope, loose gravel moves downhill with every rainfall and every pass. The solution is to contain it in a fixed structure:

• use a panel certified for slopes: Multidal is designed for surfaces up to 20 %, thanks to its closed base and clip-together panels that do not slide;
• install a solid edging at the bottom of the slope to hold back the thrust;
• prefer crushed gravel, which is more stable than rounded gravel;
• above 20 %, create terraces or steps to break up the slope.

How do you fix gravel to the ground?

There are two techniques:

• Mechanical stabilisation with a honeycomb grid: the gravel stays loose but can no longer move. The surface stays permeable, repairable and chemical-free. The geotextile bonded under ECCOgravel also stops the gravel sinking into the soil and weeds coming through.
• Bound gravel with resin or a binder: a fixed surface, but more expensive, less permeable depending on the product and hard to repair if it cracks.

For a path, yard or car park, a stabiliser grid is the easiest DIY solution and the most durable.