Photovoltaic systems on industrial buildings: structural loads and fixing
Before approving the investment, every technical department raises a crucial question: the structural capacity of the roof. The design of photovoltaic systems on industrial buildings cannot overlook a rigorous analysis of loads, as the addition of modules and mounting structures affects the roof’s load-bearing capacity, especially in relation to weather conditions.
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Structural load assessment in photovoltaic systems
The real engineering challenge is almost never the static weight of the modules (which is relatively limited), but rather the structure’s response to dynamic actions. The structural loads of a photovoltaic system must be calculated in close combination with snow loads and wind pressure (the so-called sail effect), in accordance with the provisions of the Technical Standards for Construction (NTC 2018).
A structural assessment of the industrial roof, carried out by a qualified professional, is a decisive step. This analysis determines how the existing structure, whether reinforced concrete, steel, or wood, will absorb the new stresses, taking into account geographic exposure and the system layout.
Ballast or mechanical fixing: the right solution for every roof
The compatibility and choice of mounting technology depend on the composition of the industrial roof:
- Flat roofs with bituminous membrane: to avoid perforations that could compromise waterproofing, ballast systems are commonly used for flat roof photovoltaic installations. These aerodynamic concrete elements ensure stability through their own weight and a design engineered to deflect airflow.
- Corrugated metal sheet roofs: in these cases, the preferred solution is fixing photovoltaic systems onto the corrugated sheet using special clamps or short profiles riveted to the ribs. This is an extremely lightweight system that minimizes the permanent load on the structure.
- Synthetic membrane roofs: on roofs waterproofed with PVC or TPO membranes, mounting systems can be used that involve heat-welding supports directly onto the membrane, after verifying compatibility with the roof system, ensuring watertightness without penetrating the insulation layer.
Relying on a structured EPC partner such as Southenergy ensures that the chosen anchoring solution is optimal for preserving the integrity of the building while maximizing the long-term benefits of an industrial photovoltaic system.
FAQ – Frequently Asked Questions
As a benchmark, a standard flush-mounted system weighs approximately 12-20 kg/sqm. However, for ballasted systems on flat roofs, the load can range from 20 kg to over 35 kg/sqm in high-wind areas. While many modern warehouses have adequate tolerance margins, final confirmation always requires a specific structural calculation.
Yes. Depending on the roof stratigraphy, we use ballasted structures (resting on protective mats) or, with specific synthetic membranes, heat-welded systems. Both options allow the system to be secured without compromising the vapor barrier or the original waterproofing.
If the roof is near its load capacity limits, alternative solutions can be explored. These include ultra-lightweight modules, adjusting the tilt to reduce wind lift, or designing localized structural reinforcements to ensure investment safety without compromising building stability.
Certainly. Calculating snow and wind surcharge is mandatory under NTC 2018 standards. Our simulations account for the worst-case load combinations based on the warehouse’s climatic zone to guarantee total installation safety throughout its operational life.
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