FAQ BERA Gravel Fix®
- What are the differences between BERA Gravel Fix® and similar products?
- Why are there three different sheets sizes?
- Is there a difference between the two colors?
- How much gravel do I need?
- What is the ideal stone size for the filling?
- Do I better use round stones or broken ones?
- Is a surface stabilized with BERA Gravel Fix® drivable?
- How do attach the gravel sheets to the ground?
- Can BERA Gravel Fix® also be used in sloped areas?
- How long does the geotextile last?
- Does the geotextile prevent rank weeds?
- What is the degree of maintenance of an area stabilized with BERA Gravel Fix®?
- Are the BERA Gravel Fix® sheets UV resistant?
- Are the BERA Gravel Fix® sheets frost-proof?
- Can I use BERA Gravel Fix® with wheel chairs?
1. What are the differences between BERA Gravel Fix® and similar products?
Above all, you can recognize the BERA Gravel Fix® honeycomb sheets for the following unique characteristics:
- Tapered honeycomb walls – With only 0,8 mm at the upper rim, the honeycomb walls are thinner than any other gravel stabilization system. Because of that, the honeycomb structure is distinctively less visible once the sheets are filled and finished. The lower edge, on the other hand, is 1,4 mm thick and therewith provides the highest stability for a load-bearing capacity of up to 120 to/m2.
- High-quality and strong geotextile – By using the Typar SF20 by DuPont, we are the only producer to utilize a renowned high-quality geotextile which has been tested for all relevant properties (e.g., water permeability, tearing strength, etc.). With a thickness of 68 g/m2, it is stronger than any other geotextile used with gravel stabilization systems. In addition, it is enormously durable, see FAQ point 10.
- Ecologic Production – BERA Gravel Fix® in white is the only gravel stabilization system which is „Cradle-to-Cradle” certified. This means that in the production process as well as the complete product life cycle no pollutive substances are accumulated. We achieve this by using recycled and recyclable raw materials and 100% renewable sources of energy.
2. Why are there three different sheets sizes?
In general, all three sizes are suited for all common applications including drivable areas. It is a matter of practicability which format to choose. For small garden paths, BERA Gravel Fix® Smart might be the best option in order to avoid cutting into shape too much. BERA Gravel Fix® Pro XXL on the other hand is used for really large areas because it reduces the time needed to cover the surface. In most cases, however, our standard BERA Gravel Fix® Pro will be the best compromise and is, in fact, our most sold format.
3. Is there a difference between the two colors?
Grey and white are both suitable for all common applications. Depending on the color of the filling material, one or the other version may be suited better. White has the small advantage that with time the stone dust may colorize them in the shade of the stones. Grey always stays grey and we decided against black because stones filled in rarely are black. Mostly they are dark grey or anthracite and with our grey honeycombs are less visible than black.
4. How much gravel do I need?
The honeycombs have a height of 3.2 cm. You need an additional surface cover of 1-2 cm, which means the overall height is about 5 cm. This means that per m2 you need about 50 liters of gravel, which is about 70-80 kg depending on the specific weight of the used of stone.
5. What is the ideal stone size for the filling?
Due to the size of our honeycombs we advise a stone size of 3-16 mm. Depending on the expected load the final surface has to carry, e.g., trucks driving over it, the honeycombs may be filled with a smaller size (e.g., 5-8 mm) to ensure a more compact filling of each honeycomb. The surface cover can still consist of larger stones of up to 16 mm if it is important for the general appearance.
6. Do I better use round stones or broken ones?
In the first place, it’s a matter of what you think looks better. On the other hand, broken stones become wedged more tightly, so the surface becomes more solid. Because of that, broken stones are better suited for areas which have to carry heavier loads or are driven over more frequently.
7. Is a surface stabilized with BERA Gravel Fix® drivable?
If the surface is installed according to our recommendations, it is drivable with both cars and even trucks. In this context, it is also mandatory to install a suitable substructure able to carry the load and to pick the right filling regarding stone size and type of stone.
8. How do attach the gravel sheets to the ground?
Unlike grass turf pavers, BERA Gravel Fix® does not have to be anchored in flat or even slightly sloped terrain. They will be kept in place by the stones filled in. However, it is important to provide a stable border around the whole area.
For garden paths and other areas with light use, a customary metal or plastic edging will suffice. For heavy use areas, e.g. parking lots, more solid edgings made of concrete or natural stone are more advisable.
9. Can BERA Gravel Fix® also be used in sloped areas?
Depending on the gradient of the area, the gravel sheets can be installed without additional anchoring.
The recommended tools, however, depend heavily on the local conditions. A general statement is therefore not possible.
The following pieces of advice might still be helpful:
- Up to a 10° incline the gravel sheets usually stay put without any additional anchoring, provided they have been installed according to our general recommendations. The most important rule is to install a sturdy edging.
- For additional stability, some of the honeycombs have integrated eyelets through which metal pegs or other anchoring devices can be put in order to fixate the sheet to the ground.
- For rather steep inclines it might be advisable to install additional metal borders across the gradient in order to separate the surface into separate self-supporting sectors.
Please be aware that the top layer covering the honeycomb structure is still loose material and therefore tends to roll downhill. Especially on drivable areas it is mandatory that the honeycombs are covered to not be damaged by horizontal forces (see FAQ point 12). On sloped areas, maintenance is therefore more intense and necessary more regularly.
10. How long does the geotextile last?
The geotextile used with BERA Gravel Fix® is a Typar SF20 by DuPont, a high quality textile made of polypropylene. As opposed to textiles made of other fabrics used with other gravel stabilization systems, the Typar does not decompose and lasts for more than 100 years according to the producer’s specifications. After years of usage and removal from the ground, it can be completely recycled and thus be fed back into the material circulation.
11. Does the geotextile prevent rank weeds?
Our geotextile with its 68 g/m2 is stronger than any other geotextile used with gravel stabilization and will therefore prevent virtually all weed growth from underneath the sheets. The only exception might be especially powerful sprouts such as bamboo.
Most weed growth originates from seeds which, over time, land on the surface. The Typar SF20 also helps with those. It forms a barrier which makes it difficult for the delicate roots of a young plant to penetrate in order to reach the nutrients in the earth. In addition, the high degree of water permeability of the gravel surface reduces the water supply for the young plants. Due to that, they quickly fade and are easy to remove.
As a result one can say that an additional weed prevention textile is not necessary.
12. What is the degree of maintenance of an area stabilized with BERA Gravel Fix®?
Compared to a conventional gravel surface, maintenance of an area stabilized with BERA Gravel Fix® is a lot less demanding.
Because there will be no more holes and ruts, you don’t have to fill them anymore. Only the surface cover has to be leveled from time to time in order to cover the honeycombs. This is even more important on areas with car traffic, because the surface cover absorbs the horizontal forces that originate from accelerating and mainly steering. These forces should not be at work immediately on the honeycombs.
Also, the geotextile to some degree prevents weed growth, see FAQ point 11. All in all, an area stabilized with BERA Gravel Fix® needs a lot less maintenance than a conventional gravel surface.
13. Are the BERA Gravel Fix® sheets UV resistant?
The BERA Gravel Fix® sheets are made of polypropylene which will ultimately degenerate when exposed to direct sunlight. In order to delay this process, we add UV blockers to the polypropylene granulate before production, so yes there is UV protection included.
However, this is mainly important during the storing period of uninstalled Gravel Fix® sheets. Once they have been put into the ground and filled with stones, there is no more direct sun exposure and therefore no risk of degeneration. Even if the gravel top layer might have shifted and the upper edges of some honeycombs are visible, worst case is a degeneration of the very top area of those honeycomb walls so tiny pieces could splinter. This, however, does not have any effect on the overall stability of the surface and can therefore be ignored.
14. Are the BERA Gravel Fix® sheets frost-proof?
With frost it is a quite similar situation as with UV-resistance, see FAQ point 13. Once the Gravel Fix® sheets have been installed, there is no risk of breaking or other decay due to frost.
Apart from Europe, Gravel Fix® is sold in Egypt and Russia, South Africa and Japan in various climate zones and there have been no reports of damage due to temperature.
15. Can I use BERA Gravel Fix® with wheel chairs?
Especially for wheel chairs Gravel Fix® provides a huge advantage over conventionally installed gravel surfaces. The honeycombs create an area so solid that it is perfectly drivable for the slim wheel chair tires without sinking in.
For optimal results, please use broken gravel stones rather than round ones in sizes between 2 to 6 mm. The required top layer should also be of a maximum height of 6 mm.