ECCOgravel

No. Gravel grids aren’t suitable here — use a grass grid like ECCOdal instead.

Gravel grids have smaller cells than grass grids, which already makes seeding difficult. What’s more, the geotextile acts at the same time as a root barrier: it stops weeds and prevents plants and grasses from taking root. That 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 foundation. ECCOgravel is suitable for car parks, fire service access routes and driveways, and with the right foundation it can also withstand occasional heavy traffic. In parking areas, the foundation can be designed to also handle the 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 small turning circle.

No. A solid foundation is necessary, for two reasons.

Water permeability

Without a levelling layer, there are not enough voids to collect rainwater. That water then remains on the paving instead of seeping away.

Stability

Topsoil cannot withstand the pressure of vehicles and will subside over time. A sub-base in coarse crushed stone (0–32 mm or 0–40 mm) absorbs the loads and prevents subsidence in the long term.

Yes. Follow these guidelines.

Lid height

The paving-stone lid should always sit slightly below the finished level — at most level with the underside of the gravel mats.

Avoid stabilised sand/cement around the lid

You have to break out stabilised sand/cement every time you want to access the inspection chamber. Use a concrete block on a heavy plastic underlay instead, so you can pull the block out relatively easily if needed. Then lay the ECCOgravel gravel mat on top of this concrete lid.

Cut the mats to size

Cut the gravel mats to the size of the paving-stone lid — the same size or at most 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 markers so you can easily find the chamber again. You can do this with a mark on a nearby wall, or by indicating the corners of the gravel mat above the chamber with gravel in a different colour.

Yes, but bear in mind two key points.

• Never use more than 150 kg of cement/m³ — at a higher dosage the foundation loses its water permeability.
• Do not use stabilised sand on soils that are poorly permeable. In that case, use a crushed stone base.

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

The ECCOgravel 30 Double and the ECCOgravel 40 Double have comparable technical properties: torsional load resistance, compressive strength and flexibility are very close. 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 then be built extra robustly. That additional reinforcement cost doesn’t always outweigh the saving on a thinner panel. What’s more, Belgian distributors usually 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 choice 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 surface?

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

The anti-root membrane at the bottom of the honeycomb structure also prevents fine particles from washing out into the underlying foundation. This means the water buffering in the foundation also remains intact in the long term.

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

With asphalt and concrete paving blocks, the foundation must be laid frost-free: standing water in the foundation zone can freeze and cause the surface to heave. That’s why those foundations are so deep.

With ECCOgravel gravel mats, this isn’t an issue. The foundation depth is determined solely by the load the surface has to bear.

No. Unlike concrete (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 voids in the gravel and the underlying sub-base. Even a 5 cm gravel layer can buffer up to 10 litres of water — the crushed-stone 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 water remaining on the surface.

Every type of hard landscaping requires minimal maintenance — with ECCOgravel gravel grids, this is kept to a minimum.

Top layer

Check the surface 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 avoid the gravel being blown about.

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 surface. Anything that has been washed between the hollow spaces 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 for longer and encourage weed growth.
• Do not choose gravel types with a high lime content.
• Use a foundation layer without nutritious components that drains water easily.

The geotextile at the bottom of the gravel grid acts as a root barrier and makes weed growth more difficult. Any remaining weeds are easy to remove 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 choosing 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 the weeds to take root.

The total cost depends on a number of factors.

Application: with or without vehicles

A driveway or car park requires more excavation work than a footpath or patio. A solid sub-base is crucial — without sufficient load-bearing capacity, settlement can occur.

Thickness of the gravel grid

For applications with vehicles, you should preferably choose a 4 cm thick panel, as it offers 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 categories — from around €2/m², but the price varies depending on the type and application.

Size of the project

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

For a correct tailored quotation, 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, it’s best to choose a crushed type of gravel: the particles, as it were, interlock and stay in place better than round pebbles. It’s also important to lay the gravel mats in a staggered (half-bond) pattern.

When choosing 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 trapped between the treads on tyres. For optimal 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 patios and garden paths. Gravel has the advantage that the top layer — the thin 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 break down less quickly under moving loads and turn green less quickly because they retain little water (low porosity). Soft rocks with high porosity gradually crumble and become less water-permeable, which leads to puddling and rutting. In less sunny spots they discolour green; in summer they create dust and in winter they stick to shoes.

Colour

Gravel and pebbles are natural stone and keep 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 structure 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 supple even in freezing temperatures. This means the grid won’t crack or deform when a vehicle drives over it — 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 occur when a car turns or reverses on the surface — without the grid deforming.

A geotextile that actually lets water through

All ECCOgravel gravel grids are fitted with a polyester geotextile, fully bonded to the panel. So the geotextile won’t come loose.

A common misconception: a geotextile needs to have a high density. That’s not true. What matters is that it’s strong and water-permeable — with an open structure that lets rainwater seep quickly into the sub-base. Geotextiles without an open structure clog up over time, causing puddles and mud on the surface. So with an ECCOgravel gravel grid, you 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 can be folded to 120 x 80 cm for transport. That way, you can easily carry them in the car while still installing a large area in one go. That’s also the reason behind the names ECCOgravel 30 Double and ECCOgravel 40 Double.