Vetting Your Solar Mounting System Manufacturer (Part 2) – or, The Importance of Choosing Quality Solutions and Durable Materials 
18 Mar 2021

In Part 1, interview with Rob Haddock, CEO & Founder of S-5!, we discussed the importance of qualifying a solar mounting system and its manufacturer.  We also discussed what certifications are important to consider.  In part 2, we cover what can happen when a lower-quality solution is chosen just to save money in the short-term, and why material selection is important. 

What can happen when a lower-quality solution is chosen to save a penny or two per watt?

To define “lower-quality,” refer first to Part 1 of the interview. A lower-quality mounting product simply does not comply with the extensive testing, certifications and track record of success as described previously. Without proof of quality requisites in design, production and use, it is impossible to competently engineer the roof attachment against the forces of nature working against it. In a windstorm, the entire system could be in potential jeopardy of localized or total failure. In addition, disconnected modules can pose life safety issues, ruin the roof and/or invalidate the roof’s warranty. So, choosing a lower-quality PV mounting solution is a gamble with extremely high stakes.

Specific to commercial-sized PV system applications on metal roofs, choosing a superior mounting product does not add significant cost, yet the overall assurances are quite substantial. Mounting hardware is typically less than 5% of the total system cost, but often compromised for the sake of one or two pennies per watt. This is not value engineering, but a lack thereof. Small upfront costs are inconsequential for a reliable, high-quality, long-term solution that lasts the lifetime of the roof, eliminates the need to replace failed parts and prevents future liability.

Why is material selection important, and how does it affect the longevity of the PV Array?

Material selection is important for three reasons: weatherproofing, long-term durability and metallurgical compatibility.  


When attaching to an exposed-fastened metal roof, the fasteners will be exposed to environmental elements and moisture in the air. Fasteners used by S-5! are designed to last the life of the roof―utilizing EPDM sealing washers concealed from UV degradation inside the stainless steel or zinc/aluminum caps.  These fasteners penetrate the roof so it’s critical to use high-grade, factory-applied gaskets like EPDM or butyl polymer and always static flood-tested to ASTM 2140 to avoid leakage and protect the integrity of the metal roof and building. Mounting structures that utilize these high-quality sealants and test standards eliminate the need for additional field-applied sealants and ensure longevity for the life of the roof. Fasteners provided by the mounting device manufacturer leave no room for error. Such crucial decisions are not left to the discretion of the installer and whatever is on sale at the local building material shop.  

2. Long-Term Durability 

System components should be made from 6000 series aluminum and A2-70 stainless steel. This material composition ensures the parts will outlast the life of the PV system. Product warranties should reflect this confidence. Durability also means components are extensively load tested to failure, enabling prudent engineered design and application.

3. Metallurgical compatibility 

When certain metals come in contact with each other, they can cause chemical reactions leading to corrosion. By using 6000 series and A2-70 stainless, the attachments are compatible with nearly every exposed-fastened and standing seam metal roof – whether it’s aluminum, 55% Al/Zn coated steel (Galvalume®) or zinc.

The S-5! Difference

S-5! puts decades of experience behind every product it manufactures. The durability of our products is consistent with the life expectancy of the roof. They are endorsed by the inventor of 55% Al/Zn coated steel and many other industry icons.  Our seals and fastenings – when pierce-fixing – are time proven and factory applied/provided. All clamps and brackets are load tested on more than 500 roof profiles in all materials and gauges. The Right Way® is not just our slogan―it is our credo and rule of conduct. The right way means for the life of the PV and the roof; it’s not too much to ask.

Check out Part 1 if you missed it and stay tuned for Part 3 of the exclusive interview with Rob Haddock, Founder and CEO of S-5! next week!

About S-5!

With an extensive background in the metal construction industry, S-5! Founder, Rob Haddock invented the category of penetration-free metal roof attachments in 1992. S-5!’s clamps and brackets are engineered for a variety of applications, including residential and commercial solar installations on concealed-fix and standing seam metal roofing. Made in the U.S.A., S-5!’s products have revolutionized the industry and are now installed on more than 2 million metal roofs worldwide, including 3.5 GW of PV, providing strength and longevity never before seen. For more information, visit

Prepared by

Dania Musallam

Research and Content Manager