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Agricultural structures on ground level — greenhouses, shelters, fences

A greenhouse, lean-to, shelter for machinery or field fencing is built on agricultural land, often in a wet or clayey profile and in a narrow seasonal window between harvests and new vegetation. Earthworks allow the construction to be built without concrete, with load-bearing capacity available immediately after digging — and in structures with temporary removal from the agricultural land fund, they allow the land to be returned to its original state without demolition.

Specificities of agricultural structures

The seasonal window. On the cultivated area, it is built between the harvest and new vegetation, or in the autumn. The window is short and the weather is unreliable — the technology that depends on the hardening of the concrete can only be easily installed in it.

Wet and clayey profiles. Agricultural land is often cohesive, with lowlands often having high groundwater levels. This has two consequences: the bearing capacity is sought deeper, and the compressive force, not just the torsional moment, is decisive for drilling.

Large areas and long lines. The fencing of a field or pasture means hundreds of points in a regular raster. It is the time per point and the machine's ability to move smoothly that determines this.

Limited availability of equipment and facilities. There is no paved access road on the field, no water supply or electricity connection. Wet processes are logistically challenging.

Protection of the agricultural soil fund. Construction on agricultural land is subject to the regime of Act No. 334/1992 Coll. The difference between permanent and temporary expropriation fundamentally affects what happens to the land after the construction ends.

ZPF and demountability: what screws solve and what doesn't

Here it is necessary to be precise, because this is often simplified.

Ground drilling does not replace the permitting process. Construction on agricultural land requires consent to expropriation from the ZPF — permanent or temporary — under Act No. 334/1992 Coll. The choice of the type of foundation does not change this obligation. The ground screw itself does not mean that the expropriation is not being considered.

Where the holes decide is the return of the land to its original state. U temporary deprivation As part of the agreement, the commitment is to return the land to agricultural use after the construction is completed. The removable base will fulfill this obligation by unscrewing the bolts and leveling the area. In the case of concrete footings, it involves dismantling, removing the rubble, and subsequent reclamation — which is not cost- or time-efficient.

The exception is agrivoltaics. Under the amendment no. 183/2024 Sb., land from the ZPF is not at all being taken away from agrovoltaic plants, and agricultural activity must continue throughout the entire operating period. There, the reversible base is directly a prerequisite for compliance with the regulations — in detail on the page Agrivoltaics on the ground ridges.

The specific conditions for the confiscation, the amount of the levies, and the scope of the reclamation are determined by the relevant ZPF protection authority. We recommend verifying them before choosing a foundation technology.

Why ground piles for agricultural structures

Without wet processes and without infrastructure. There is no more importing of concrete, no more waiting. In a field without a paved road and connections, this makes a significant difference in logistics.

It will fit into the seasonal window. The construction is set up immediately after digging. The entire cycle — foundation and assembly — is feasible in a short period of time between the harvest and vegetation period.

Lower dependence on weather conditions. The rotation is not a wet process, so the risk associated with the temperature during solidification and the rain during concreting is eliminated.

The search for portability is pursued deeper. In wet and clayey profiles, it is necessary to get under a low-bearing layer. The longer rod allows for penetration in a deeper layer without the need to expand the base into the surface.

Dismantleability. In addition to the obligations associated with temporary removal from the ZPF, this is also a practical advantage from a practical perspective — the shelter or fencing can be relocated in accordance with changes in farming practices.

Documentation for each point. The telemetric recording of the moment and depth serves as a basis for the statics and, in the case of funded projects, as part of the documentation of the implementation.

Recommended machine for agricultural construction

Glentor C65 — for greenhouses and moisture-proof profiles. As the only model in the series, it can handle a screw into 3.5m and to the pilot 4.3 m. Where there is several meters of wet or clayey profile above the loadbearing layer, the length of the screw is the decisive parameter — more than the nominal torque. The 12,000 N clamping force ensures drilling even in cohesive soils. Side-mounted drilling allows for working close to the existing structure, for example when expanding a greenhouse complex.

Glentor D50 — for fencing and extensive lines. The D50 is not a separate machine, but additional drilling equipment With a weight of 480 kg and powered by the hydraulic system of the supporting machine (200 bar / 70 l/min), this is the most economical way to self-dig for an agricultural enterprise that already operates a tractor or loader with corresponding hydraulics: a torque of 5,000 Nm at 37 rpm and a drill diameter of up to 2.5 m will cover fences, posts, lightweight shelters and support structures.

Glentor B80 — for larger structures on a dry profile. Maximum torque in a row (8,000 Nm) and a pressure of 12,000 N for shelters for machinery, stables and prefabricated halls on a more load-bearing base.

CriterionC65D50B80
Typeself-propelled machineadditional equipmentself-propelled machine
Torque6,500 Nm / 20 rpm5,000 Nm / 37 rpm8,000 Nm / 20 rpm
Downward force12,000 N6 350 N12,000 N
Max. screw / pilot3.5 / 4.3 m2.5 metres2.5 metres
Mass3 050 / 3 250 kg480 kg2,480 kg
MotorHatz, 43.7 kWwithout motorHatz, 43.7 kW
Suitable forgreenhouses, moisture-proof profilesfences, posts, linessheds, halls, dry profile

The implementation process

  1. Consent to deprivation from the ZPF and project preparation. Determination of permanent or temporary removal according to the nature of the structure. The structural engineer will determine the type, length, and arrangement of the bolts.
  2. Geotechnical survey. In the case of wet and clayey profiles, the crucial factor is determining the depth of the load-bearing layer and thus the length of the screw. Design according to Eurocode 7.
  3. Test drilling. Verification of the actual depth of the load layer at a representative point before starting the main work. It is always worth doing in wet profiles.
  4. Setting and turning with a telematics record. The holes are drilled to the designed depth, the torque and depth are recorded for each point.
  5. Assembly of the structure. Fencing the greenhouse, shelter or enclosure immediately after digging, without waiting for it to harden.
  6. Documentation for grant projects. The recording from the telematics unit contains an accurate torque and depth profile for each base point. The customer supplies a complete output profile of the rotation installation for the installation, which serves the authorized structural engineer to verify the limit load-bearing states according to Eurocode 7 and the investor as proof of technical qualification and reversibility for grant titles (e.g., from the PRV or Modernization Fund). 

Screw depth in wet and clayey soils

The wet clayey horizon has low bearing capacity and changes in moisture cause it to expand and contract. The base on which this layer rests is not stable — which is a classic cause of subsidence of lightweight agricultural structures.

The solution is to insert it into a deeper, more robust layer. This is where the difference between the models becomes apparent: while the A70, B80, and D50 work with a screw up to 2.4–2.5 m deep, the C65 reaches 3.5 m with a screw, and 4.3 m with a pilot. If geotechnical surveys show a layer that is more than 2.5 m deep, the C65 is the only option within the range.

The second parameter is the compressive force — in solid tracks, it is the one that drives the soil into the ground. The C65 and B80 offer 12,000 N, which is more than twice that of the A70.

Frequently Asked Questions

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