Hot-rolled structural sections for PV steel substructures and ventilated facades

Hot-rolled structural sections for PV steel substructures and ventilated facades

PV steel substructures and ventilated facade systems made of hot-rolled T-sections and angles provide an optimal flexural stiffness-to-weight ratio. Furthermore, the use of structural steel sections in grades S235JR, S275JR, and S355J2 allows for transferring complex wind and snow loads. As a result, this prevents micro-cracking in photovoltaic panels and guarantees long-term structural stability.

Application of T-sections and angles in substructures of ventilated facades and solar farms

PV steel substructures and modern ventilated facade systems form the foundation of contemporary industrial and energy construction. Therefore, the proper selection of mill-rolled sections directly determines the trouble-free operation of facilities. What is more, hot-rolled open profiles feature significantly higher load-bearing capacity than their cold-formed thin-walled counterparts. Consequently, hot-rolled steel elements serve as a benchmark for reliability in harsh environmental conditions.

1. PV steel substructures and facades: mechanical and environmental requirements

First and foremost, modern PV steel substructures operate under continuous exposure to variable atmospheric loads. Accordingly, pursuant to standard PN-EN 1991-1-4 on the PKN website, support frames must withstand significant forces caused by wind pressure and suction. In addition, the self-weight of the cladding and accumulated snow must be taken into account.

For this reason, to maintain the Serviceability Limit State (SLS), the maximum deflections of elements must not exceed permissible values. However, angular deformations of the frame are equally critical. As a result, even minor deviations in solar farms can induce micro-cracks in the silicon structure of photovoltaic cells.

2. Angles and T-sections in facades and solar mounting frames

Ventilated facades demand strict rigidity of the supporting frame. At the same time, efforts are made to minimize the contact area with the wall to reduce thermal bridging.

• Angles in brackets and sub-frames: For wall mounting, equal angles and unequal angles are widely utilized. Since the geometry of unequal legs allows directing the bending moment toward the higher load, a reduction in total structural mass is achieved.
• T-bars as primary load-bearing profiles: On the other hand, at vertical facade panel joints, hot-rolled T-sections represent the optimal choice. The flat flange of the T-section guarantees a broad contact surface. Furthermore, its web effectively transfers shear forces.

3. Durable PV steel substructures for ground-mounted solar farms

When designing utility-scale solar power plants, structural resistance to dynamic wind gusts becomes essential. For this reason, PV steel substructures constructed from hot-rolled profiles demonstrate clear advantages over cold-formed sections.

Technical Parameter	Hot-Rolled Section (e.g., T-bar / Angle)	Thin-Walled Cold-Formed Section
Wall thickness (t)	Standardly ≥ 4.0 mm	Typically 1.5 – 2.5 mm
Buckling resistance	Very high (rigid cross-section)	Prone to deformation
Corrosion allowance	Outstanding (large material allowance)	Limited at cut edges

In multi-support mounting frames, UPN channels are also utilized as load-bearing purlins. Meanwhile, for custom designs, dedicated special profiles offer tailored solutions. This provides investors with complete confidence in geometric precision. Furthermore, quick calculation of tonnage requirements is enabled by the steel weight calculator, integrated with the documentation presented in the WOST product catalog.

4. Corrosion protection: PV steel substructures in severe environments

Both solar farms and building facades are located in outdoor environments ranging from C3 to C5 atmospheric corrosivity categories. Therefore, steel surface protection is an absolute priority.

1. Hot-Dip Galvanizing (PN-EN ISO 1461): Hot-rolled profiles feature thicker walls. Consequently, the dipping process creates a thick Fe-Zn alloy layer that provides protection for decades.
2. Prevention of galvanic corrosion: However, direct contact between steel and aluminum (e.g., the PV module frame) requires EPDM insulating washers. Otherwise, a galvanic cell will form.

5. Summary and profile selection from WOST S.A.

In summary, PV steel substructures and facade framing built from hot-rolled profiles represent a dependable engineering solution. Since steel grade S355J2 exhibits high yield strength, reducing structural mass while maintaining full load capacity becomes achievable.

We invite you to explore the documentation included in our structural steel product range. Furthermore, our dedicated technical advisory team and contact service will assist in selecting the optimal parameters for any project.