S-5!® PVKIT™ 2.0 Solar Rooftop Solutions
The concept of combining PV arrays with standing seam metal roofing is growing—for good reasons. Metal roofs have a life expectancy of more than 40 years. Shouldn’t the mounting system last as long? With S-5! zero-penetration attachment technology and PVKIT 2.0, the solarized metal roof is the most sustainable system available –and without compromising roof warranties! PVKIT 2.0 is the also the best solution for attaching PV modules directly to any exposed fastener metal roof.
Suggestions for Spacing of S-5! Clamps for PV Assemblies
The following suggestions assume that determination has been made that the roof to which the S-5! clamps will be attached is structurally adequate. Any loads imposed on the S-5! clamps will be transferred to the panels. Panel seams must have sufficient flexural strength to carry these loads. Panels must also be adequately attached to the building structure, and the structure must be sufficient to carry these loads. The makers of S-5! clamps make no representations with respect to these variables. It is the responsibility of the user to verify this information, or seek assistance from a qualified design professional, if necessary.
The key to frequency and spacing of attachment points for PV is to distribute loads to the metal panels in a manner that is consistent with the intended distribution of loads from the roof panels into the building structure. With very few exceptions, the attachment of a single S-5! clamp (even the “Minis”) to the seam will be stronger than a single point of attachment of the seam to the building structure. Hence the “weak link” is not the S-5! clamp, but the attachment clips that hold the metal panels to the building structure, or the beam strength of the roof panel seam itself.
Whether utilizing rail or Direct-Attach™, the best approach for the PV attachment to the standing seam roof is to populate points of attachment so that the wind uplift loads experienced by the modules are distributed evenly into the roof below. This reduces “point loads” to the roof panels to a tolerable level. Most pre-engineered metal buildings utilize roof panel attachment to the structure every 10 sq. ft. So how often should rails be attached? No less than once for every 10 sf of roof surface. The same is true for Direct-Attach™. Most 60-cell modules are ≤18 sq. ft. in surface area. By utilizing the four module attachment zones as directed by module producers, and attaching the module directly to the roof seam, the resulting tributary load area to each point of attachment is ≤9 sq. ft. Such an attachment scheme should evenly distribute wind loads into the building structure through the panels and their attachment, as was intended in the original roof construction assembly.
Note: Wind dynamics are complex, and S-5! advises review by a qualified professional who understands wind effects and as well as metal roof design and construction.