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A step-by-step guide to building a climate change proof hail structure

How to make a hail protection system for vineyards: a guide by Gel GiussaniIn the current context of increasingly evident climate change and the growing incidence of violent weather phenomena, crop protection becomes a top priority for farmers. Among the various preventive measures, the implementation of anti-hail installations emerges as an indispensable investment to preserve the quality and yield of crops such as vineyards and orchards.

With this article, we at Gel Giussani would like to give an overview of the basic elements and steps for creating a hail-resistant structure for both professionals and DIYers.

Basic elements and tools needed for the creation of hail protection systems

Hail protection systems consist of a number of crucial elements that work synergistically; these include:

  • Ground anchorage: solid, well-fixed anchorage points in the ground, essential for supporting the structure of the plant and resisting the forces of wind and the weight of the hail net.
  • Poles: vertical elements made of wood, iron or concrete that support the tension cables and the hail net.
  • Hooks and turnbuckles: essential for securing nets to poles and maintaining adequate tension.
  • Joints: to connect network sections and ensure continuous and homogeneous coverage.
  • Wires and Ropes: tension cables that are mounted on poles and used to support the hail net. The tension of the wires is essential to maintain the stability of the structure and ensure effective protection against hail.
  • Post covers: components that are installed on top of posts to anchor tension wires and to ensure the safety of the installation.
  • Anti-hail net: this is the heart of the system. The anti-hail net consists of a nylon or polypropylene fabric that is stretched over the tension cables to protect the vines from the impact of hailstones.
  • Net fixing accessories: these are plates for fixing on the row line of the hail protection cloth.

In addition, the following tools are essential for installation:

  • Drills and excavators: used to create the holes for the piles.
  • Spirit levels and theodolites: to ensure the precise alignment of the poles.
  • Hammers and drills: for fixing accessories and supports.

Some of the tools mentioned, such as drills and excavators, are generally used by professionals. If you are a do-it-yourselfer, you must turn to them to ensure that the work is done correctly and safely.

Detailed steps for a professional hail protection system

To set up a professional hail protection system, it is essential to follow a well-planned and defined sequence of operations.

Planning the hail protection system

The first step in this process is project planning.

In this phase, the area that will be covered by the anti-hail system must be precisely defined, the most suitable type of net must be chosen, and the support materials must be determined according to the specific climatic and cultivation conditions of the area. Careful planning allows the system to be adapted to the specific conditions of the site, thus ensuring optimal protection.

Site survey and soil analysis

Next, a detailed site survey and in-depth analysis of the terrain must be carried out. This phase includes an assessment of the characteristics of the terrain, such as its slope, composition and the presence of any natural or artificial obstacles. Knowing these details is crucial to designing a stable and durable structure. The soil analysis also involves identifying the type of soil (sandy, clayey or silty), evaluating the topography of the site and analysing the climatic conditions, including the frequency and intensity of hailstorms and wind speed, a factor of fundamental importance for the stability of the structure.

For example, if a hail protection system is to be installed in a vineyard located on a steeply sloping hill, it is crucial to consider how the slope might affect the stability of the support posts and the distribution of nets. A steep slope may require deeper, well-anchored support posts to prevent the risk of subsidence, as well as considering an adequate drainage system to prevent rainwater from accumulating and compromising the structure.

Designing the structure

Once the soil analysis has been completed, we move on to the design of the structure. This phase involves the sizing of the nets, the choice of posts and anchoring systems, taking into account various factors that are crucial to ensure the stability and effectiveness of the anti-hail system. Correctly sizing nets means calculating the total area to be covered and choosing nets that are wide and long enough to provide continuous and uninterrupted coverage.

The choice of poles is another key aspect: poles must be selected according to their strength, durability and ability to support nets under heavy loads, such as those caused by strong winds or hail accumulations. For example, in an area exposed to strong winds, concrete poles might be appropriate, while in an area with less extreme weather conditions, wooden or iron poles might be sufficient and cheaper.

Anchoring systems are essential to keep the posts stable and ensure that the nets remain taut and well secured. Anchors must be chosen according to the type of soil and climatic conditions. For example, in sandy soils, screw anchors that penetrate deeply into the ground may be necessary to ensure stability. In clay soils, where hold may be greater, plate or stake anchors may be sufficient.

Wind resistance is another critical factor to consider. Nets must be designed and installed to minimise the wind resistance typical of a hailstorm.

Finally, assess the load-bearing capacity of the structure. During an intense hailstorm, nets can accumulate a considerable hail load, which must be supported without fail. Therefore, the nets must be made of strong materials and the posts must be strong enough to support this additional load.

Installation of poles

After the hail protection system has been designed on paper, it is time to act. As a first step, the excavators will have to remove any obstacles and level the surface to ensure a solid base for the support poles.

Next, the drills will have to dig deep holes to ensure sufficient stability for the piles, taking into account the data provided by the levels and theodolites.

Installation of anchors, cable covers and support cables

Installation of anchors, cable covers and support cablesOnce the supporting piles have been concreted, it is necessary to proceed with the insertion of the anchors into the ground, aligning with the piles and digging deep holes to ensure secure fastenings.

Next, we proceed to the application of the pile covers on the top of each support pole. In this context, we at Gel Giussani have products for fixing the covers to the support poles, such as U-bolts and threaded eyelets. This procedure is essential to pass the tension cables over the support poles.

Once this has been done, it is now time to mount the support cables in the special anchors and support pole covers; in this case one of the most recommended threads is undoubtedly the Gelinox P1/P3. This 304 stainless steel wire is ideal for anti-hail systems and is designed to withstand strong stresses and adverse weather conditions.

Mounting the hail net

Once the cables have been placed, we proceed with the stretch of the anti-hail nets, fixing them to the poles through locking systems such as hooks and tensioners. It is essential to maintain a constant tension along the entire network to avoid sagging or tearing, thus ensuring a lasting and stable protection against hailstorms. The mains voltage must be periodically checked and adjusted if necessary to maintain the effectiveness of the system.

Extra: periodic maintenance

Once the hail protection system has been completed, it is important to carry out regular checks and maintenance. Regular checks of net tension and pole stability are essential to ensure the longevity of the system. Preventive maintenance, such as adjusting net tension and reinforcing poles, can prevent damage and extend the life of the hail protection system.

How to make a DIY hail protection system for a small plot of land?

Making a DIY hail protection system follows the same steps as above, but requires some specific considerations.

Planning, soil analysis, design of the structure and installation of the net remain fundamental steps. However, for some operations such as the creation of post holes and ground levelling, it may be necessary to rely on professionals or hire tools such as drills and excavators.

In addition, small plots of land usually have two rows. In this case, the procedure can be adapted by installing higher support posts in the centre of the field and shorter ones at the sides. This approach should be done in order to create a slope in the hail net (ideally between 15% and 40%), so as to mitigate the impact of hailstones and facilitate water run-off. The slope not only improves the net’s resistance to damage, but also facilitates drainage and maintenance.

Even in a DIY hail protection system, it is crucial to maintain a constant tension in the net and to periodically check the stability of the poles to ensure the durability and effectiveness of the whole system.

Conclusions and the role of Gel Giussani

In conclusion, the implementation of hail protection systems is a fundamental step in protecting vineyards, orchards and other crops from unpredictable weather events. As specified in the article, the correct installation of anchors, poles, tension cables and, above all, hail netting is crucial to ensure effective protection against hail damage.

In this context, we at Gel Giussani are committed to providing quality accessories to support farmers in creating robust and reliable hail protection systems. If you would like more information about our products or customised advice for your project, please do not hesitate to contact us.