When installing solar panels on metal roofs, it's crucial to understand the common roof sheet profiles: angle type, standing seam and trapezoidal. Among them, the trapezoidal corrugated steel sheet is widely used in industrial and commercial buildings due to its high strength and low cost. However, unlike standing seam roofs that allow direct clamping, trapezoidal roofs require specialized mounting solutions,typically using L feet, clamps, or rail free systems to ensure a secure, leak proof, and code compliant PV installation.

 The methods mentioned above,such as direct clamping on standing seam or angle type roofs typically require no roof penetration, as clamps rely on compression force. Today, however, we focus specifically on trapezoidal sheets. Unlike other profiles, trapezoidal roofs often need a different approach because their flat crests and lower ribs limit standard clamp use.

Due to the unique profile of trapezoidal sheets, clamps alone cannot secure solar panels effectively on the roof surface. So how is it done in the industry? Here are several common and proven methods currently used for trapezoidal corrugated steel roof PV installations let me share them with you.

1. Trapezoidal clamp + self-tapping screws on both sides

 Features: The nailing points need to be properly waterproofed and sealed, and the thickness of the color steel plate cannot be too thin, otherwise the self-tapping screws will not be able to withstand the force.

 2. Trapezoidal clamp + structural adhesive

 Features: No damage to the tile surface, no risk of leakage; however, the warranty period and pull-out resistance of the structural adhesive are questionable.

3. Trapezoidal clamp + long self-tapping screws (or rivet bolts) anchored into the original structural purlins.

 See the diagram below for rivet bolt installation.

 4. Trapezoidal clamp + cold welding process

 Features: Requires high-level construction techniques; thin tiles are prone to weld penetration.

For more information needed or any inquiry,please feel free to contact Yumisteel team.