ECCOgravel

No. Gravel mats are not suitable here — use a grass grid such as ECCOdal instead.

Gravel mats have smaller openings than grass grids, which already makes seeding difficult. Moreover, the geotextile also acts as a root barrier: it stops weeds and prevents plants and grasses from taking hold. This keeps your gravel surface weed-free for longer.

ECCOdal grass grids have a specific plastic base that is suitable for sowing grass.

Yes, provided there is a solid sub-base. ECCOgravel is suitable for car parks, fire service access routes and driveways, and with the right sub-base it can also withstand occasional heavy traffic. In parking zones, the sub-base can be designed to also handle runoff water from the roadways.

What to avoid

Tight turning with an articulated lorry combination must be avoided at all times. ECCOgravel is also not suitable for forklift trucks due to their tight turning radius.

Yes, but keep two points in mind.

• Never use more than 150 kg of cement/m³ — with a higher dosage, the foundation loses its water permeability.
• Do not use stabilised sand on soils with low water permeability. In that case, work with a crushed stone sub-base.

Yes. Follow these guidelines.

Height of the cover

The manhole cover should always be slightly below the finished level — at most level with the underside of the gravel mats.

Avoid stabilised sand/cement around the cover

You have to chip away stabilised sand/cement every time you want to access the chamber. Instead, use a concrete block on a heavy plastic underlay, so you can pull the block out relatively easily if needed. Then lay the ECCOgravel gravel mat on top of this concrete cover.

Cut the mats to size

Cut the gravel mats to the size of the manhole cover — the same dimensions or up to 5 cm larger. That way, when accessing the chamber you won’t have to move a large area of mats and gravel.

Mark the location

Add indicators so you can easily find the chamber again. This can be done with a marking on a nearby wall, or by indicating the corner points of the gravel mat above the chamber with gravel in a different colour.

Yes, that’s possible — but with an important caveat.

The ECCOgravel 30 Double and the ECCOgravel 40 Double have similar technical properties: torsional load resistance, compressive strength and flexibility are close to each other. The difference lies in how the load is distributed to the sub-base: the thicker the panel, the better the force is spread.

You can use the ECCOgravel 30 Double for applications with vehicles, but the sub-base must be built extra robust. That additional reinforcement cost does not always outweigh the savings from a thinner panel. Moreover, Belgian dealers generally stock the ECCOgravel 40 Double in larger quantities, meaning that variant is always available.

Yes. The open structure of the geotextile guarantees water permeability, even in the long term.

Gravel selection is crucial

Do not choose gravel types with fractions finer than 4 mm. After installation, the gravel compacts, but without a fine fraction, permeability remains guaranteed.

What about fine particles that wash onto the paving?

Dust, sand, soil and leaf debris that end up on the surface do not affect water permeability. They fill the voids without further compacting, while the gravel continues to transfer loads.

The root barrier fabric at the bottom of the honeycomb structure also prevents fine particles from washing out into the underlying foundation. This keeps water storage capacity in the foundation intact in the long term.

No. Because the gravel mat is flexible and the gravel is not bound, frost heave has no effect on an ECCOgravel surface.

With asphalt and concrete pavers, the base layer must be installed frost-free: standing water in the base zone can freeze and cause the surface to heave. That’s why those bases are so deep.

With ECCOgravel gravel mats, this is not an issue. The base depth is determined solely by the load the surface must carry.

No. Unlike concrete (block paver) surfaces, ECCOgravel does not require a minimum slope. Even during heavy downpours, the buffer capacity is sufficient to handle the water.

How it works

Rainwater immediately drains into the hollow spaces of the gravel and the underlying base layer. Even a 5 cm gravel layer can buffer up to 10 litres of water — the crushed-stone sub-base takes care of the rest.

For illustration

The maximum 20-year rainfall intensity in Belgium is 270 l/s/ha. Over a period of 10 minutes, that amounts to 16.2 l/m². ECCOgravel handles that without any water remaining on the surface.

Every type of paving requires minimal maintenance — with ECCOgravel gravel grids, that effort remains limited.

Top layer

Check the paving occasionally, depending on traffic intensity. Where the honeycomb structure becomes exposed, cover it again with gravel.

Leaves

Preferably remove leaves once a year by raking, blowing or vacuuming. Do not use gravel types with a fraction smaller than 4 mm, to prevent the gravel from being blown away.

Soil or manure

Remove soil or manure with a shovel down to the honeycomb structure. A new layer of gravel of about 1 cm is sufficient to restore the paving. What has washed in between the cavities has no effect on water permeability.

Weeds

Limit weed growth by making the right choices during installation:

• Do not choose gravel types with high porosity — they retain water longer and promote weed growth.
• Do not choose gravel types with a high lime content.
• Use a sub-base without nutrient components that drains water efficiently.

The geotextile at the bottom of the gravel grid acts as a root barrier and makes weed growth more difficult. Any remaining weeds can be removed easily by hand, because the roots concentrate in the honeycomb structure. Removal with hot air or a burner is also possible — both are preferable to chemical weed killers.

The choice of gravel is essential. By opting for a harder, less porous gravel, the amount of weeds that grow through the top layer can be reduced. This is because there is less space for weeds to take root.

The total cost depends on a number of factors.

Application: with or without vehicles

A driveway or parking area requires more excavation work than a footpath or terrace. A solid base is crucial — without sufficient load-bearing capacity, subsidence can occur.

Thickness of the gravel grid

For applications with vehicles, it’s best to choose a 4 cm thick panel, because it provides better load distribution. For applications without vehicles, a 3 cm panel is sufficient.

Type of gravel

There are many different types of gravel in various price ranges — from about €2/m², but the price varies depending on the type and the application.

Project size

The larger the project, the more the total cost will of course vary from one situation to another.

For a correct, tailor-made price quote, it’s best to contact one of our distributors or installers.

The maximum gradient is 20%, which corresponds to an incline angle of about 10°.

On a slope, you preferably choose a crushed type of gravel: those particles sort of interlock and stay in place better than rounded pebbles. It’s also important to lay the gravel mats in a staggered (half-brick) bond pattern.

When choosing the gravel, you take four parameters into account.

Grain size

Do not choose gravel types with a minimum fraction smaller than 4 mm: finer particles stick to shoes or get stuck between the tread patterns on tyres. For optimum compaction in the honeycomb, limit the maximum diameter to 16 mm.

• Use without vehicles: 4–8 mm
• Use with vehicles: 8–16 mm

Shape

We call round gravel types pebbles; crushed gravel types we call gravel. Pebbles are more pleasant for terraces and garden paths. Gravel has the advantage that the top layer—the layer that hides the honeycomb structure from view—shifts less quickly. Gravel is therefore the recommended choice in places where vehicles drive over the paving.

Hardness

Hard gravel types crumble less quickly under rolling loads and turn green less quickly because they retain little water (low porosity). Soft rocks with high porosity gradually disintegrate and become less permeable to water, which leads to puddles and rutting. In less sunny places they turn green; in summer they create dust, and in winter they stick to shoes.

Colour

Gravel and pebbles are natural stone and retain their colour even after a long time. For lighter gravel or pebble types, preferably choose a white ECCOgravel gravel mat; for darker types, a black one.

The build-up consists of two layers: a sub-base and a levelling layer. The thickness depends on the application.

Sub-base

Use limestone or porphyry chippings (0–32 mm or 0–40 mm).

• Without vehicles: 20 to 30 cm
• With vehicles: 30 to 50 cm

Levelling layer

Use limestone or porphyry chippings (1–3 mm or 2–4 mm) or screened sand.

• Without vehicles: 10 to 15 cm
• With vehicles: 5 to 10 cm

ECCOgravel gravel grids are made from HDPE (High-Density Polyethylene). This material is naturally more flexible than other thermoplastics such as polypropylene, and it remains pliable even at freezing temperatures. This means the grid won’t crack or deform when you drive over it with a vehicle — not even in winter.

High load capacity, even during manoeuvres

When filled, an ECCOgravel gravel grid has a compressive strength of 400 tonnes/m², making it suitable for vehicles up to 3.5 tonnes. In addition, each grid has plastic reinforcements between the honeycomb cells. These reinforcements absorb the torsional loads that arise when a car turns or pivots on the surface — without the grid deforming.

A geotextile that really is permeable

All ECCOgravel gravel grids are equipped with a polyester geotextile, fully bonded to the panel. So that geotextile will not come loose.

A common misconception: a geotextile must have a high density. That’s not true. What matters is that it’s strong and water-permeable — with an open structure that allows rainwater to seep quickly into the subsoil. Geotextiles without an open structure clog over time, causing puddles and mud on the surface. With an ECCOgravel gravel grid, you therefore don’t need to invest in an additional drainage system.

Large format, easy to transport

ECCOgravel gravel grids are large (120 x 160 cm = 1.92 m² per panel), but foldable to 120 x 80 cm for transport. This way, you can easily transport them by car and still install a large surface area in one go. That’s also the reasoning behind the names ECCOgravel 30 Double and ECCOgravel 40 Double.