Testing components and materials for quality and durability is essential in manufacturing. This is especially true for metal roof panels. By identifying material and machine-related issues early, manufacturers can address problems before they reach the market.
Organizations such as Underwriters Laboratories (UL) and ASTM International perform material tests. These tests help maintain high product standards and ensure reliable performance in extreme conditions like high winds and heavy rains.
The first group of tests focuses on the manufacturing process to ensure various standards are met during production.
Panel squareness affects performance and aesthetics; therefore, manufacturers often check to ensure each panel is square during their normal QC process. This precision prevents installation issues and guarantees a seamless fit.
Next, it’s important to measure the rib profile, shape, and height of the panels to ensure they were produced according to tolerance and the desired specifications. These features contribute to the panel's structural integrity and aesthetic appeal.
While the first two components (squareness and rib profiles) apply primarily to panel goods, various checks and balances should also be performed for structural and trim materials. Accurate dimensions and degree of bends are both virtually important to ensure material performance.
Structural Integrity Testing
We use three methods to test roof panels’ structural integrity. These tests help us maintain their safety and reliability.
Instead of panel manufacturers, steel mills perform the first of the tests to confirm structural integrity by checking the strength and flexibility of the metal. These tests involve stretching the material until it breaks to quantify its tensile strength and ductility. These qualities determine the maximum weight and mechanical force tested components can withstand.
Load testing simulates various weights and pressures the panels encounter in real-world conditions. This typically involves applying gradual pressure to the panels to measure their resistance and identify the maximum load they can bear before deformation or failure. This test measures the panels' reliability under non-structural stresses like heavy snow or high winds.
In Class 4 testing for impact resistance, manufacturers subject panels to conditions mimicking severe weather, such as hailstorms. This testing involves dropping steel balls from varying heights onto the panels to evaluate their durability and resistance to damage. These stringent tests ensure that metal roof panels offer superior performance and longevity.
Wind Uplift Testing evaluates the panel system's ability to stay safely secured to the building when subjected to uplift. In addition to testing the panel's resistance to buckling, it also tests the strength of the panel seam connection and the clip's ability to anchor the system to its substrate. There are multiple wind uplift test procedures; however, they all involve creating a pressure differential between the top and bottom of an installed panel system and testing to either a target design pressure or system failure. Learn more about uplift testing.
The third type of panel testing focuses on weather resistance.
Metal panels must withstand prolonged exposure to moisture and environmental pollutants without deteriorating. Corrosion resistance testing subjects the panels to accelerated aging processes to simulate years of weathering in days. This verifies the effectiveness of protective coatings and materials.
These tests measure panels’ ability to prevent leaks and drafts. Air and water infiltration tests replicate real-world conditions by applying pressure differentials and water sprays to the panels to ensure water doesn’t penetrate the building envelope.
Water head testing for standing seam roofs — specified in ASTM E2140 — evaluates the panels' resistance to water penetration under static pressure. This test involves submerging the seams under 6” of standing water for 24 hours. If one drop of water penetrates the roof system, the product fails the ASTM E2140 test.
Lastly, all McElroy Metal’s roof panels undergo thorough performance analysis to ensure they’re installation-ready at the point of sale.
Impact testing assesses the panel’s durability under sudden forces. Similar to Class 4 testing for hail impact, this involves simulating impacts with objects such as weighted pendulums, sandbags, and simulated wind debris to gauge panel resistance to dents and perforations.
This evaluates the panels’ resistance to fire. Panels are exposed to flames to observe their reaction, including ignition point, flame spread, and smoke production.