The article below discusses how best to install ECCOgravel gravel mats. This process can be summarised in 9 steps. Gravel pavements are “in”, but they have one major drawback, however. If they are frequently walked or driven on, the gravel can start to shift. The comfort of the gravel pavement can suffer greatly as a result.
Installation of gravel mats ECCOgravel
Installing your ECCOgravel gravel mats is easy and quick. Before you start, accurately determine which slab type you need and choose the right foundation depth.
How to choose the right plate height
You can choose between a 3 cm or 4 cm high plate. The 3-cm ECCOgravel slab and the 4-cm slab have similar characteristics (abrasion resistance, pressure resistance, flexibility, etc.). However, the load distribution (of cars, etc.) to the foundation is better with a 4-cm slab than with the 3-cm one. We can explain this simply using the example below.
1. You put a sheet of paper on your hand and hit it with a hammer. 2. You put a phone book on your hand and hit it with a hammer. Conclusion: the distribution of force is better in the second case. Extend the same to ECCOgravel and we may conclude that the foundation will be subjected to less load when the slab is thicker. Should the ECCOgravel 30 Double slab then never be used in applications with cars? Yes, provided the foundation is very strong. The extra cost for this additional reinforcement does not always outweigh the savings on a thinner slab.
What type of gravel do I use in gravel mats
It is recommended to take gravel types whose minimum fraction is larger than 4 mm. Finer fractions may stick to the shoes or get stuck between the profiles on the tyres of the car. To achieve optimal compaction in the honeycomb, we recommend limiting the maximum diameter of the gravel to 16 mm. – Application without trolleys: ideally 4 mm to 8 mm – Applications with trolley; ideally 8 to 10 mm to 16 mm
Round gravel is referred to as gravel, broken gravel as gravel. Gravel is more pleasant for terraces and garden paths, while gravel has the advantage that the top layer (the layer on top of the honeycomb structure to make the structure invisible) will not move as easily. Gravel is therefore recommended in places where vehicles will drive on the pavement.
Hard gravel is less likely to crumble under moving loads and less likely to turn green because it retains less water (low porosity). A soft rock -with high porosity, on the other hand, pulverises easily and dissolves over time. Consequently, soft rock will eventually become permeable to water, leading to puddling and rutting. Moreover, it will turn green on non-sunny sides. Finally, soft rock gravel will cause dust formation in summer and stick to shoes in winter.
Gravel or pebble is a natural stone and retains its colour even after a long time.
What requirements must the foundations meet?
No frost-free depth required
Due to the flexibility of the slab and because the gravel is not bound, freezing has no effect on the ECCOgravel pavement. When designing foundations for asphalt and concrete clinkers, care will always be taken to ensure that no water remains in the zone where frost may occur in the foundation. This is because frost can cause the asphalt or concrete pavement to freeze up. This is why the foundation depth for such materials is so extensive. The foundation depth for ECCOgravel is therefore determined solely by the loads the pavement will have to endure.
No slope required
Unlike concrete (clinker) paving, ECCOgravel® does not require a minimum slope. Even with very heavy rainfall, the buffer capacity will be sufficient to deal with the rainwater. A small calculation: the maximum 20-year rainfall intensity in Belgium is 270 l/s/ha. For 10 min, this amounts to 16.2 l/m2. The rainwater will immediately seep into the hollow spaces of the gravel and the underlying foundations. Thus, we reduce the risk of losing the functionality of the pavement due to water remaining on the pavement. Up to 10 litres of water can already be stored in a 5 cm gravel layer. It goes without saying that a minimal crushed stone foundation will take care of the rest.
Installing gravel mats in 6 steps.
1. Removal of topsoil
Of course, you must start by removing the topsoil for this you will have to do the necessary digging, after this the boards are placed. These should extend 2 cm above the level of the top of the slab.
2. Installation of the foundation case
Then place the foundation case at least 25 cm deep; for ideal placement of ECCOgravel gravel mats, work in layers of 20 cm maximum and compact using a vibrating plate. You can use, for example, limestone chippings, porphyry chippings or crushed concrete rubble (grain size distribution: 0-32 mm or 0-40 mm). We do not recommend brick rubble, as it will pulverise over time.
3. Application of the levelling layer
Next, the levelling layer is placed in fine gravel, which must be compacted and levelled for optimum results. The depth of the levelling layer in applications with trolleys is 5 cm, applications without trolleys ideally 15 cm. The levelling layer can be made with limestone or porphyry (grain distribution: 2-4 mm, 1-3 mm or 0-4 mm) or with sieve sand.
4. Installation of the ECCOgravel gravel mats
Finally, install ECCOgravel gravel sheets with overlapping geotextile, these are best cut with a grinding wheel. Then lay the slabs in half-brick bond.
5. Placement of the gravel layer
Finally, the gravel is placed; driving loads on the unfilled gravel sheets is not recommended. Levelling is done with a shovel, brush, rake and squeegee, do not compact the decorative gravel. Leave the gravel 1 to 2 cm (1 cm for finer gravel and 2 cm for coarser gravel) above the slabs. Due to natural compaction, the gravel will settle slightly. In time, there should be just enough gravel to make the ECCOgravel mat invisible.
6. Inspecting and levelling
A few weeks after initial commissioning, inspect and level. Add gravel where necessary, subsidence will not occur now!