FAQ BERA Gravel Fix®
- What are the differences between BERA Gravel Fix® and similar products?
- Why are there different heights and formats of gravel sheets?
- Is there a difference between the colors?
- How much gravel do I need?
- What is the best size of gravel to fill the honeycombs?
- Do I rather use round or broken stones?
- Is an area stabilized with BERA Gravel Fix® accessible by vehicles?
- How do I fix the sheets to the ground?
- Can BERA Gravel Fix® also be used in sloped areas?
- How durable is the geo-textile?
- Does the geo-textile provide any protection against weeds?
- What maintenance is needed on the finished gravel surface?
- Are BERA Gravel Fix® sheets UV-resistant?
- Are BERA Gravel Fix® Matten frost resistant?
- Are areas stabilized with BERA Gravel Fix® accessible with wheelchairs?
1. What is the difference between BERA Gravel Fix® and similar products?
First and foremost, you recognize the BERA Gravel Fix® honeycomb sheets from the following unique features:
- Tapered walls – With an upper edge that is only 0,8 mm thin, the honeycomb walls are thinner than with any other gravel stabilization system. It makes the sheets much less visible in the finished gravel surface.
The 1,4 mm strong lower edge provides high stability of up to 120 to/m2.
- High quality and strong geo-textile – With the Typar SF20 by DuPont we use a high-end geo-textile which is tested and certified for all relevant features, e.g., water permeability, tensile strength, etc. Its thickness of 68 g/m2 is among the highest used with gravel sheets and, in addition, it is extremely durable, see FAQ #10.
- Ecologically sustainable production – BERA Gravel Fix® is the only gravel stabilization system which is “Cradle-to-Cradle Certified”TM Silver. Bottom line, this means that from production throughout the complete product-life-cycle no pollutive waste occurs. This is accomplished by using recycled and recyclable raw materials plus up to 100% renewable energy during the production process.
2. Why are there different heights and formats of gravel sheets?
We offer two different heights:
– 32 mm for the Smart, Pro and Pro XXL versions
– 26 mm for the Lite versions
Both are generally suitable for common private applications, including areas lightly frequented by cars. The sheets with 32 mm height, however, are even stronger and can therefore be used for heavy traffic, which means either heavy vehicles (such as trucks or construction machines), or areas with a high traffic frequency.
Which of the different sheet dimensions is most suitable depends on the project size. 40 x 80 cm should be best for narrow garden paths and small areas, whereas the large 120 x 230 cm sheets are better for large areas of 1,000 m2 or more. The 80 x 120 cm sheets are a good compromise regarding handiness and therefore our most sold size.
3. Is there a difference between the colors?
All colors are equally suitable for all applications. Best make your choice depending on the color of the gravel you plan to use.
4. How much gravel do I need?
Always add 1-2 cm for a covering layer to the height of the sheets. This leads to
> 26 mm sheets = ca. 4 cm total height = ca. 40 liters/m2 = ca. 60 kg/m2
> 32 mm sheets = ca. 5 cm total height = ca. 50 liters/m2 = ca. 75 kg/m2
5. What is the best size of gravel to fill the honeycombs?
Depending on the height of the sheets we recommend
> 26 mm sheets: 3-12 mm
> 32 mm sheets: 3-16 mm
Especially when using the 32 mm sheets for areas with heavy traffic, we recommend filling the honeycombs with smaller sized broken stones (e.g., 5-8 mm) to get a more compact filling with fewer empty space. For the cover layer you may still use 16 mm stones.
6. Do I rather use round or broken stones?
Main reason to choose one or the other is your personal preference regarding the look of the surface. However, broken stones tend to interlock more and are therefore better suited for areas with heavy traffic.
7. Is an area stabilized with BERA Gravel Fix® accessible by vehicles?
If the gravel sheets have been installed according to our laying instructions also regarding the sub-base, the finished surface can be accessed by cars and motorbikes (26 mm & 32 mm sheets), or even trucks and heavy machinery (32 mm sheets).
8. How do I fix the sheets to the ground?
Unlike turf pavers, our gravel sheets do not require anchoring to the ground or interconnections between sheets on level or even slightly sloped ground. They will be kept in place by the filled in gravel.
Just bear in mind to install a stable border surrounding the area. For garden paths and other lightly used areas standard metal or plastic edging will suffice. Areas trafficked by cars or heavily used otherwise should be surrounded by concrete or stone borders.
9. Can BERA Gravel Fix® also be used on sloped areas?
Depending on the gradient the sheets can also be installed on slopes with or without additional fixation. Which means of anchoring are necessary depends heavily on the local conditions. A flat answer is therefore not possible.
Here is some helpful orientation:
- Up to a gradient of 10° the sheets usually do not need additional anchoring if they have been installed according to our laying instructions including stable edging.
- For additional stability we included eyelets in selected honeycombs of every sheet. Through those you can stick metal or other pegs to fix the sheets to the ground.
- At steep gradients it might be advisable to install stable borders lateral to the slope to segment the area into smaller stable sections.
Please remember that the cover layer still consists of loose stones which can roll downhill. Especially on trafficked areas it is of paramount importance to keep the plastic sheets covered to protect them from horizontal emerging from accelerating or steering cars (see also FAQ #12). On slopes, the maintenance of the gravel surface is higher and more urgent.
10. How durable is the geo-textile?
We use the Typar SF20 by DuPont which is a high-quality, non-woven textile made of polypropylene. Unlike fabrics used by other manufacturers, this material does not rot and keeps its properties for 100 years according to the producer. When uninstalled, the Typar SF20 can be completely recycled.
11. Does the geo-textile provide any protection against weeds?
The Typar SF20 geo-textile by Dupont which we use, is 68 g/m2 strong and provides a good protection, albeit it’s not an explicit anti-weed textile.
If weeds start to grow on a gravel area, the plants did not work their way up from underneath, but the seeds usually landed on the surface. In this case, the Typar SF20 helps by providing a barrier which cannot be easily penetrated by the tender roots. The young plants do not reach the nutrients in the soil needed for faster growth. In addition, the water permeability of the gravel surface dries out the weeds. They wither and can be plugged out easily.
12. What maintenance is needed on the finished gravel surface?
Compared to traditionally installed gravel areas, the maintenance level of surfaces stabilized with BERA Gravel Fix® is considerably lower.
Since there are no more wheel ruts etc., filling up these holes is no longer necessary. Only the top layer needs to be leveled from time to time to cover the sheets. This is especially important if the surface is accessed by vehicles. The cover layer softens the horizontal forces that occur when a car accelerates or steers and prevents them from affecting the plastic sheets.
The integrated geo-textile helps reducing weed growth (see FAQ #11) so it can be concluded that much less maintenance is needed on surfaces stabilized by BERA Gravel Fix®.
13. Are the BERA Gravel Fix® sheets UV resistant?
The BERA Gravel Fix® sheets are made of polypropylene which deteriorate under direct sun exposure. To slow down this process we integrate UV-blockers that protect for a limited amount of time.
However, this is only relevant while the sheets are being stored. Once they are installed into the ground and the honeycombs are filled with gravel, the sheets are no longer exposed to direct UV radiation. Hence there is no longer a risk of deterioration.
Even if the gravel cover layer should shift and reveal the upper edges of the sheets for a short period of time, there is no risk to the stability of the area. Worst case is that these upper edges become a little brittle, but this process does not automatically spread into the whole sheet.
14. Are the BERA Gravel Fix® sheets frost resistant?
With frost the situation is similar to UV-resistance, see FAQ #13. Once the sheets are installed and filled with gravel, there is no more risk of deterioration due to frost.
BERA Gravel Fix® sheets have been installed not only in different parts of Europe, but also in Egypt, Russia, South Africa and Japan. So far there have been no problems connected with weather or temperatures, whatsoever.
15. Are areas stabilized with BERA Gravel Fix® accessible with wheelchairs?
Especially regarding the accessibility with wheelchairs, BERA Gravel Fix® offers huge advantages over conventional, loose gravel areas. The sheets create a surface that is so compact and stable that slim wheelchair tires no longer sink in.
For the best possible results, we advise to use broken stones instead of round ones with a size of 2-6 mm. The necessary cover layer should not exceed 6 mm.