Photovoltaics on lightweight halls: Technology, structural analysis & mounting

Photovoltaics on lightweight halls offers companies an interesting opportunity to use large roof areas for their own electricity generation. Lightweight halls have long established themselves as a flexible, economical, and quickly implementable alternative to conventional industrial halls. The range extends from simple storage tent halls with textile membrane roofs to semi-permanent hall systems and permanently used steel structures with insulated roof and wall systems.

The transitions between a temporary solution and a permanent corporate asset are often fluid. It is not uncommon for industrial tents or halls that were originally intended only as temporary storage for a few months to remain in operation for many years or even decades due to their practical utility.

For companies that Photovoltaics want to retrofit, this distinction is crucial. Depending on the type of hall, roof construction, and load-bearing capacity, the technical possibilities and prerequisites for installing a PV system differ significantly.

What are lightweight halls?

Basically, a lightweight hall is understood to be a hall construction that, in contrast to a classic steel or concrete hall, features a comparatively lightweight supporting structure is built. The supporting structure usually consists of galvanized steel or aluminum. Depending on the intended use, the roof and walls consist of a robust PVC-coated membrane or insulated sandwich panels. Lightweight halls are frequently used as storage, production, logistics, or workshop buildings and are characterized by their short construction time as well as their high flexibility from.

In colloquial language, lightweight halls are often referred to as „tents.“ In fact, however, there are significant differences between a simple tent camp hall and one permanent lightweight structure. While tent storage halls are mostly for a temporary use are designed, modern lightweight halls are tailored to a long-term operation designed. They meet the applicable requirements for wind and snow loads and can be equipped with thermal insulation, industrial sectional doors, heating, lighting, or crane runways. The type of roof structure used ultimately determines whether—and under what conditions—a photovoltaic system can be installed.

Why the roof type is crucial for photovoltaics

Not every lightweight hall offers the same conditions for the installation of a PV system. The decisive factor first is for which Purpose of use the hall was originally designed. Lightweight structures designed for long-term use generally come with comprehensive documentation that includes structural analyses, Structural engineering and information regarding Permissible roof loads. In contrast, for halls that were originally erected as temporary storage or tent structures and later remained in permanent use, these documents are often missing or must first be checked and supplemented. Before a decision can even be made regarding the installation of a PV system, a new structural re-evaluation is therefore frequently required.

In principle, lightweight halls with their large, mostly unshaded roof surfaces offer excellent conditions for on-site solar power generation. Compared to conventional permanent buildings, however, their load-bearing reserves are often lower and must be carefully evaluated on a case-by-case basis. At the same time, the roof structures vary considerably: while some halls feature textile membrane roofs, others have trapezoidal sheet metal roofs or insulated sandwich roofs. This not only determines which mounting systems can be used, but also which types of modules are suitable and what additional loads the roof can permanently support.

Therefore, three questions are crucial for planning a photovoltaic system: Which Roof type Is it available? How can the Substructure be securely fastened? And which static reserves Is there funding available to cover the additional costs associated with the solar power system?

Which types of roofs are best suited for solar panels?

Whether a lightweight industrial building is suitable for photovoltaic systems depends largely on the roof design and the existing support structure. While some roof types can be fitted with PV systems relatively easily, others require customized solutions. The key factor is how the additional load is transferred into the structure—via the roof sheathing itself, via rafters or joists, or via a separately installed substructure.

Trapezoidal Sheet Metal Roofs: Ideal Conditions for Standard PV Systems

Lightweight halls with trapezoidal sheet metal roofs often offer the best conditions for a photovoltaic system. Installation is usually carried out using special brackets on the high ribs of the metal sheet, allowing the loads to be transferred specifically into the roof structure. However, even in this case, it is a prerequisite that the load-bearing capacity of the sheet metal and the substructure is adequately verified.

Sandwich roofs: Possible, but depends on the construction

For sandwich panels, suitability depends heavily on the type of panel used, the seams, the thickness of the outer layers, and the core material. The fastening points must be evaluated on a case-by-case basis, as not every sandwich panel is designed to withstand additional roof loads or localized loads.

Membrane roofs/fabric roofs: Special case with increased planning effort

With textile membrane roofs, the additional load generally cannot be absorbed directly through the roof skin. Instead, the force must be transferred via special constructions into load-bearing elements such as main or edge beams. As a result, PV projects are possible, but almost always require individual solutions and a detailed structural analysis.

Flat roofs: Depending on load-bearing reserve and fastening system

For flat roofs, which are somewhat rarer in lightweight industrial buildings, lightweight systems with low ballast or mechanical fastening can be an option. However, the deciding factor is whether the building structure can support the additional loads from dead weight, ballast, and wind suction.

Custom Designs: Customized Testing Without Standard Solutions

Special roof structures are often used, particularly in lightweight industrial buildings. In such cases, individual tests and structural analysis reports are required, as no standard solutions exist. This includes, for example, buildings with mixed roof structures, retrofitted support systems, or atypical spans, where the load distribution cannot be clearly assigned to any of the standard roof types.

Overview of roof types

Types of fastening and substructures for lightweight halls

Heavy glass-on-glass modules with traditional ballasting are not suitable for lightweight industrial buildings. Such systems require load reserves of 30–45 kg/m² or more. In these cases, Lightweight modules and alternative fastening systems are used because they reduce the additional load. Common variants that often manage with a total load of under 10 kg/m² are:

• Suspension from rafters or beams (clamping): Load is introduced directly into the load-bearing structure – the standard solution when the support structure is accessible and sufficiently dimensioned.
• Installation on trapezoidal sheet metal: Bracket in the crown, mostly without rafter drilling – the most common solution for metal roofs.
• Roof-penetration-free flat roof systems: Only possible if the hall structure offers sufficient residual load-bearing capacity for the (usually ballasted) mounting system.
• Bonded Lightweight Construction Systems: Permitted only if the roof covering has been approved for this purpose and wind suction resistance has been verified by calculation.
• Special substructures: They distribute the load across multiple points, thereby optimizing the number of fastening points required.

For fabric roofs, the following applies explicitly: Fastening directly into the membrane itself is not the norm. The load must be transferred to the supporting structure—usually via main or edge beams.

Structural Analysis: The Decisive Factor

Structural engineering is the decisive inspection point for photovoltaic systems on lightweight buildings. Unlike traditional industrial halls, lightweight structures are often designed to be very material-efficient. Therefore, the available load reserves for additional roof installations are usually limited.

For PV planning, in addition to the weight of the modules and the substructure, other factors must also be taken into consideration:

• additional dead load: Weight of modules, mounting system, cables, and fasteners
• Wind and Snow Loads: in particular, wind suction forces on large, lightweight roof surfaces
• Load introduction: what is crucial is whether the forces can be safely transferred into beams, rafters, or other load-bearing structural elements
• Existing documentation: Structural analysis and structural design make the evaluation much easier

A blanket statement about how much weight a lightweight hall roof can support is therefore virtually impossible. The permissible additional PV load depends on the respective construction, the roof type, the span, the year of construction, and the original design of the building.

Therefore, before installing a photovoltaic system, it is always necessary to check which load reserves are actually available and which mounting system suits the respective hall construction. Because what is crucial is not only, how much can support a roof, but above all, how the additional load is safely transferred into the supporting structure.

In general, however, simple, originally temporary tent structures with membrane roofs can also be retrofitted with photovoltaics – usually via special fastenings on the main or edge girders rather than the membrane itself. This is particularly relevant where a PV obligation must be met and the hall is considered a sealed surface.

Limits of PV installation: When is a lightweight hall unsuitable?

Not every lightweight structure can be easily equipped with a photovoltaic system. The decisive factor is always whether the additional load can be permanently and safely transferred into the supporting structure. For example, a PV retrofit is impossible if:

• the load-bearing reserves of the overall structure are also too low for wind and snow loads.
• the roof membrane is unsuitable or does not allow direct fastening.
• the load transfer is missing or no suitable load-bearing elements are present.
• the structure is weakened by corrosion, material fatigue, or other damage.
• Structural calculations are missing or cannot be renewed.

However, these points do not automatically mean that a PV system is ruled out here altogether. Frequently, adapted mounting concepts, additional reinforcements, or project-specific special solutions can enable implementation. Especially in the case of fabric roofs and very lightweight structures, the path to realization usually leads via targeted load introduction into main or edge beams.

Therefore, especially in the case of temporarily planned lightweight structures that have evolved into permanent storage or production areas over time, an early structural analysis is recommended. This allows technical limitations to be identified early and avoids unnecessary delays during subsequent PV retrofitting.

Practical checklist for lightweight structures before PV planning

When planning a photovoltaic system for a lightweight industrial building, CUBE CONCEPTS follows a strict procedure:

1. Determine roof type and load transfer path
2. Obtain a structural report on the remaining load-bearing capacity
3. Check wind zone and snow load zone
4. Select the appropriate mounting type depending on the roof type and load reserve
5. Plan for Maintenance Access and Future Maintenance

For specific photovoltaic projects on lightweight industrial buildings, we are consistently able to develop customized and Suitable substructures Develop anew.

Frequently Asked Questions