ECCOgravel

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

Gravel grids have smaller cells than grass grids, which already makes sowing more difficult. In addition, the geotextile acts as a weed-control membrane: it stops weeds and prevents plants and grasses from taking root. 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 foundation. ECCOgravel is suitable for car parks, fire brigade access routes and driveways, and with the right foundation can also withstand occasional heavy traffic. In parking areas, the foundation can be designed so that it also manages 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 short turning circle.

Yes, but bear two points in mind.

• 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 with low water permeability. In that case, use a crushed-stone sub-base.

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

Water permeability

Without a levelling layer, there aren’t enough voids to capture 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 of coarse crushed stone (0–32 mm or 0–40 mm) takes the loads and prevents subsidence in the long term.

Yes. Follow these guidelines.

Height of the cover

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

Avoid stabilised sand around the cover

You have to break out stabilised sand every time you want to access the inspection 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 block-paving 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 markings so you can easily find the chamber again. You can do that with a mark 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 vehicle applications, but then the sub-base must be constructed extra robustly. That additional reinforcement cost does not always outweigh the saving on a thinner panel. In addition, Belgian distributors generally stock the ECCOgravel 40 Double in larger quantities, meaning that variant is always available from stock.

Yes. The open structure of the geotextile guarantees water permeability, also 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 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 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 keeps the water buffering 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 block pavers, the foundation does need to 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 does not apply. The foundation depth is determined solely by the load the surface must carry.

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 base layer. Even a 5 cm gravel layer can buffer up to 10 litres of water — the crushed-stone foundation 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 this without water remaining on the surface.

Every type of hard surfacing requires a minimum maintenance effort — with ECCOgravel gravel grids, this remains limited.

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 with a fraction smaller than 4 mm, to avoid the gravel 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 surface. Whatever has washed into 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 a 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 nutrient-rich components that drains water efficiently.

The geotextile at the bottom of the gravel grid acts as a root barrier and hinders weed growth. Any remaining weeds can easily be removed 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.

Choosing the gravel is essential. By opting for a harder, less porous gravel, the amount of weeds growing 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 terrace. A solid foundation is crucial — without sufficient load-bearing capacity, settlement can occur.

Thickness of the gravel mat

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

Size of the project

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

For an accurate tailored 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, it’s best to choose a crushed type of gravel: the particles interlock, as it were, and stay in place better than rounded pebbles. It’s also important to lay the gravel mats in a half-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 trapped between the tread patterns on tyres. For optimal compaction in the honeycomb, limit the maximum diameter to 16 mm.

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

Shape

We call round gravel types pebbles; crushed gravel types are called gravel. Pebbles are more pleasant for patios 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 moving loads and turn green less quickly, because they retain little water (low porosity). Soft rocks with high porosity gradually pulverise and become less permeable to water, leading to puddles and rutting. In areas without much sun they discolour green; in summer they cause 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 remains pliable even at freezing temperatures. This means the grid will not break or deform when you drive over it with a vehicle — not even in winter.

High load-bearing 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 vehicle turns or pivots on the surface — without the grid deforming.

A geotextile that really lets water through

All ECCOgravel gravel grids are fitted with a polyester geotextile, fully bonded to the panel. That geotextile therefore will not come loose.

A common misconception: a geotextile must have a high density. That’s not true. What matters is that it is strong and water-permeable — with an open structure that allows rainwater to seep quickly into the subsoil. Geotextiles without an open structure become clogged 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 can be folded to 120 x 80 cm for transport. This makes them easy to transport by car while still installing a large surface area in one go. That is also the reason behind the names ECCOgravel 30 Double and ECCOgravel 40 Double.