How to Choose a Reliable Solar Mounting System? 

5 Essential Criteria Every U.S. Homeowner Should Know
        Solar mounting systems (A solar mounting sys) look like only metal strips and screws. But different systems will cause power reduction, and also turn photovoltaic systems in storms into "flying discs". In the United States, every year due to installation failures, situations such as roof leaks, panel falling off, fires will occur. And a good mounting system can be used for more than 25 years, which is longer than the lifespan of the panels.There are choices for aluminum alloy, galvanized steel, etc., and also for ballast-mounted and ground-mounted types. How should an average American homeowner choose appropriately? Avoid sales talk; remember 5 basic criteria.





1. Check for Certification: UL 2703 Is the “Entry Ticket” to the U.S. Market
        In the United States, rooftop or ground-mounted solar installation systems must first pass UL2703 certification. This is not a label affixed by the manufacturer, but a third-party test conducted by UL, involving 3 core aspects: relatively strong structure, electrical grounding and fire resistance performance. Simply put, UL2703 certification allows the system to be less likely to be damaged during strong winds, heavy snow, extreme heat or electrical problems.Many American homeowners don't realize that local inspectors will reject non-UL certified PTOs. Worse still, when a roof leaks or catches fire due to uncertified installation, the insurance company will refuse to underwrite the claim. You must ask the installer to provide the system's UL 2703 certification, and also confirm that the certification is applicable to the roof type and wind zone.If they hesitate or show up with expired documents, just transfer them to other companies.

2. Consider the Climate: Your Mounting System Must Be “Built for the Region”
        The climate of the United States is diverse. A properly installed system in South Dakota may not work in Minnesota or Nebraska. When selecting a system, the installer needs to perform structural calculations based on your address, and state two key pieces of data: design wind speed and snow load. For example, Miami-Dade County requires the system to withstand 170 miles per hour of wind, while Chicago only needs to withstand 115 miles per hour of wind. As for snow load, parts of northern New York State have a snow load of 60 pounds per square foot, while Atlanta has almost no snow load.A well-reputed installation manufacturer has load diagrams with different configurations. Installers need to select the appropriate bolt specification spacing based on roof rafter spacing, age, and materials. Do not轻信 such words as "this system can be used nationwide". In coastal areas such as Corpus Christi, Texas, Louisiana and Hawaii, it is necessary to inspect the corrosion resistance grade of the system. Standard aluminum alloy is acceptable in a salt spray environment, but galvanized steel will rust within a few years if it does not have the ASTM A653 G90+ coating.

3. Consider the Roof Type: No Single Bracket Fits All Roofs
        There are differences in the shape and size of residential roofs in the United States. Different roof surfaces require different installation methods. The common one is asphalt shingle roofs. Its standard is to use L-shaped feet with waterproof rubber gaskets and flashing, which are fixed to the rafters by tension bolts. The key point is that the bolts need to enter the center of the rafters, not just the roof sheathing part.The installer said to use self-tapping screws to fix the plywood. Need to pay attention that there may be cutting corners, strong winds may blow off the panels and roof sheathing. Standing seam metal roofs do not use penetrating fasteners, instead use special clamps (such as S-5!) to clamp the raised seams. This can avoid drilling and eliminate the hidden danger of water leakage, but metal roofs need to be able to resist additional wind loads. Clay/slate tiles are the most challenging, you cannot drill holes on the tiles, use tools to cut the tiles to expose the wood, install brackets, then trim the tiles or use a cap layer to cover. This is very time-consuming and will increase labor costs.Single-story commercial buildings (EPDM/TPO roof with ethylene propylene diene monomer rubber), can use ballasted racks or through-penetration anchors. The former uses concrete blocks without damaging the waterproof layer; the latter requires professional waterproof maintenance. Either choice needs a structural engineer to check the roof's load-bearing capacity.

4. Materials and Construction: Aluminum Alloy vs. Galvanized Steel—Which to Choose?
        In the US photovoltaic support system market, mainstream materials include aluminum alloy and galvanized steel. Aluminum alloy (6005 - T5/6061 - T6) has the characteristics of light weight, corrosion resistance and high processing accuracy, and is often used to make roof supports. It has a disadvantage that its cost is slightly higher than that of steel, and its rigidity is slightly poor when installing large-span ground supports.High-quality aluminum alloy brackets are anodized, with a thickness reaching the standard of ≥10 microns. Gently scratch with a key, if metal scratches can still be seen, it means the oxide layer is too thin. Galvanized steel (ASTM A653 Gr 33/50) has the characteristics of high strength and low cost, and is applied to ground brackets and large commercial projects, but it is prone to rust. High-quality galvanized steel adopts the hot-dip galvanizing process, and the coating thickness reaches ≥45 microns (approximately G90 grade).Poor quality steel is electroplated with zinc (used for cheap screws), which produces white rust within a few months. The test goes like this: a magnet does not attract aluminum alloy but attracts galvanized steel. For steel brackets, you need to ask whether it is hot-dip galvanized or electrogalvanized, and you need a coating thickness report. The bolts, nuts and washers used for connection should be 304 stainless steel, not ordinary galvanized carbon steel. Many cheap brackets have cut corners, and the bolts will rust and seize within 2 years, making it impossible to unscrew them to replace the panel.

5. Consider the Brand, Warranty, and Installer’s Reputation
        Choose a long-proven racking brand. In the US, IronRidge, Unirac and other brands dominate the residential market. These brands' products have UL certification, accessories are easy to compatible, and have experienced engineering support.The installer recommends an unknown brand without off-site support, do not choose it even if its price is 30% cheaper than other brands. A good bracket brand has a warranty period of 10 to 25 years, its warranty covers defects in pipe materials and coating failure, but does not cover improper installation. In addition, the installer's response is sometimes more important than the bracket brand itself. For the best IronRidge bracket, if the installer does not align the bolts with the rafters, or does not tuck the flashing under the roof tiles, there will be water leakage.