The Industry’s Biggest Milestone: First FM 4478 Approval for Standing Seam Roofs

In June 2023, the solar mounting industry achieved a significant breakthrough. Centroplan‘s commercial roof-mounted photovoltaic system, SolaRoof Metal, became the first rigid module and securement system for standing seam metal roofs to receive FM Approval with a 1-90+ wind uplift rating-2. This certification, granted under FM Approvals Standard 4478 for Roof-Mounted Rigid Photovoltaic Module Systems, represents the highest standard for rooftop PV system safety and performance-2.

The SolaRoof Metal system integrates three critical components: S-5! PVKIT HUR (High Uplift Resistance) mounting attachments, Butler® MR-24® roofing panels, and JA Solar PV modules-2. FM Approvals’ rigorous testing evaluated internal and external fire resistance, hail damage resistance, wind uplift performance, electrical safety, and gravity load resistance—including functionality under 120 pounds of snow per square foot-2.

The S-5! standing seam clamp design used in this system does more than just secure PV modules; it inherently fortifies and strengthens the underlying roof structure-2. As Cy Ketchum, FM Approvals’ Materials Engineer, noted, “The demand for more approved products, including systems with expanded wind uplift ratings, continues to gain momentum”-2. This certification provides industrial and commercial companies with scientific-backed validation that their roof-mounted solar systems can withstand increasingly severe climate risks.

Rail‑Less Systems: The Dominant Trend of 2023

Perhaps the most significant shift in metal roof solar mounting in 2023 has been the accelerating adoption of rail‑less mounting solutions. Traditional rail-based systems have long been the conventional choice, but rail-less direct-attachment technology is moving the industry norm in a new direction-12.

Key Advantages of Rail‑Less Mounting

Rail-less systems leverage a metal roof’s existing standing seams as inherent “rails” for mounting solar PV via mechanical attachments, eliminating the need for conventional racking rails-12. The benefits are compelling:

Reduced Component Weight: Rail-less mounting components weigh up to 85% less than railed systems-12

Lower Hard Goods Costs: Material costs can be reduced by up to 35%-12

Improved Load Distribution: Direct attachment to the roof provides 25% better load distribution across the roof surface-12

Zero Penetrations: Preserves both roof integrity and manufacturer warranties-12

Logistical Savings: With 90% less volume than rail-based systems, shipping costs can be 60% lower-12

Labor Efficiency: Installation labor savings of 30–50% are achievable, as rail-less design allows roof clamps to be aligned and installed “on‑the‑fly” using the module as a spacing jig-12

S‑5! PVKIT HUR 2.0: The First‑of‑Its‑Kind High Uplift Resistance System

Building on the momentum of the FM Approval milestone, S‑5! launched the enhanced S‑5‑PVKIT HUR 2.0 in 2023—a rail-less solar mounting solution specifically engineered for extreme wind uplift performance-14. This system is approved to FM 4478, the toughest PV standard from FM Approvals, and is designed to withstand hurricane-force winds as well as heavy snow loads-14.

The PVKIT HUR 2.0 incorporates several innovative design features:

Extended Overhead Grabs: 6-inch (152 mm) length provides a larger contact area with the PV module’s frame, preventing release even as the module frame bows under extreme forces-14

Enhanced Contact Surface: A new contact surface design and angle increases grip on the module frame-14

Reinforced Baseplate: Prevents module bending and disengagement under high wind uplift forces-14

Together, these features significantly improve the structural integrity of the module-to-roof attachment. The system is compatible with exposed-fastened, standing seam, and corrugated metal roof types-14.

S‑5! RC Clamp: Expanding Compatibility for Riverclack® Profiles

In July 2023, S‑5! announced its new S‑5‑RC™ clamp, designed specifically for attaching rooftop accessories to the Riverclack® metal roof profile-10. The two-piece design interfaces with the rib geometry to create a mechanical interlock strong enough for most rooftop applications while protecting the roof from corrosion and preserving thermal cycling characteristics-10.

Key features of the S‑5‑RC include:

Exclusively for Riverclack® profiles

Compatibility with both rail-based and rail-less PVKIT® solar solutions

Zero-penetration attachment

Made of high-tensile structural aluminum with no maintenance required

Warranted for the life of the roof

This product exemplifies the industry trend toward specialized, profile-specific mounting solutions that maximize compatibility without compromising roof integrity.

SunModo’s SKU-Reduction Strategy: MRB and NanoBit

Recognizing the logistical challenge posed by the wide variety of metal roof profiles, SunModo introduced two new metal roof attachments in 2023 with a focused mission: reducing product SKUs-7. SunModo CEO Steve Mumma noted that the company was selling approximately 17 different metal roof attachment SKUs—a number he described as “not fun for anybody”-7.

The company’s solution comprises two innovative products:

NanoBit: A smaller, lower-cost alternative to the NanoMount, designed to fit in tighter spaces on metal roofs where the wider base of traditional mounts may not work. It is particularly well-suited for trapezoidal roof profiles and requires only a single lag bolt-7.

MRB (Multi‑Roof Bracket): Designed to fit the vast majority of metal roof types (excluding standing seam), the MRB features flexible “wings” that can fold down to attach to corrugated or trapezoidal roofs. The wings can slide in and out to accommodate a wide range of shapes and profiles, while an EPDM gasket ensures a reliable waterproof seal-7.

By streamlining their product line, SunModo aims to reduce inventory complexity for distributors while simplifying the installation process for contractors—a win-win for the entire solar supply chain.

SnapNrack TopSpeed: Ground‑Attached Mounting Innovation

In February 2023, SnapNrack unveiled TopSpeed, a completely new approach to solar mounting that attaches to the panel on the ground before being hoisted to the rooftop-5. This design aims to reduce rooftop installation time by over 50%, significantly improving worker safety-5.

The installation process involves three steps:

TopSpeed mounts are attached to solar modules on the ground

Wire management and MLPE components are set in place

Modules are quickly affixed to the universal skirt on the roof

TopSpeed is UL certified and rated for wind loads from 90 mph to 180 mph, as well as snow loads up to 90 pounds per square foot-5. Constructed from alloy aluminum and 300 series stainless steel, the system features retained fasteners and deck mounts, enabling single-tool installation-5. The product was showcased at Intersolar North America 2023 in Long Beach, California-5.

IBC TopFix 200: Modular Versatility for Pitched Roofs

IBC Solar presented its IBC TopFix 200 modular system at Intersolar Europe 2023. Utilizing a range of clamps, rails, roof hooks, and molded sheet metal tiles, this system is suitable for universal use on almost any pitched roof-. The system’s modular design allows installers to adapt quickly to different roof geometries, making it a flexible solution for diverse metal roof applications.

AeroCompact COMPACTMETAL: Solutions for Trapezoidal Sheet Metal Roofs

For trapezoidal sheet metal roofs, AeroCompact offered its COMPACTMETAL TS and TL solutions in 2023. The TS trapezoidal sheet metal short rail provides an optimal price-to-performance ratio, while the TL bridge solution supports both longitudinal and transverse installation-. These specialized solutions address the growing commercial and industrial market, where trapezoidal metal roofing is prevalent on warehouses and office buildings.

Patent Innovation: S‑5! Adds 21 New Patents in 2023

Demonstrating the rapid pace of innovation in this sector, S‑5! announced the addition of 21 new patents issued in 2023 alone, bringing the company’s total patent issuances to 133 since 1991-22. The most notable among these is U.S. Patent Number 11,808,043 for the S‑5! Bonding Clip, which bonds and grounds standing seam metal roof panels to one another for safety purposes if a roof becomes energized with electricity-22-32.

Other patents issued in 2023 spanned multiple global jurisdictions, including:

Australia: PVKIT® solar solution, TrapBracket™, RibBracket™ I-IV, S‑5‑N Clamp

Canada: PVKIT® 2.0 solar solution

India: Standing Seam Clamp

United States: GripperFix® utility mounting solution, WindClamp™ 2X

As S‑5! Founder and CEO Rob Haddock stated, “Our research and development team always strives to ‘innovate, improve, and re-innovate,’ while doing things The Right Way!”-22. S‑5! solutions are now installed on more than 2.5 million metal roofs worldwide, supporting over 6 gigawatts of solar PV in 70+ countries-22.

Top Solar Mounting Products Recognition

Solar Power World recognized several metal roof mounting solutions among its 2023 Top Solar Mounting Products-28. Notable metal roof–compatible products included:

CHIKOUSA RAD MOUNT: A simple but radical design providing installers with flexibility to mount to both rafter and deck, featuring 6 screws, 6 EPDM washers, and a T-bolt-28

Pegasus Solar SkipRail: Eliminates entire rows of rails, mounts, and roof penetrations by leveraging excess strength built into PV modules-28

QuickBOLT The Throne: A standing seam solution with pre-assembled L-feet and set screws, featuring a cross-knurled grip plate that enhances pull-out resistance and prevents damage to the roof-28

S‑5! PVKIT HUR: Recognized for its ability to withstand extreme wind uplift forces, including hurricane-category winds, as the first metal roof PV mounting system certified to FM4478