Determining if the galvalume roof is the gauge specified

Candace Benyei
We have a farm, and recently had several buildings re-roofed and a couple of new sheds put up by an Amish contractor. Because of my concern regarding snow load and wind, I had asked the contractor to put 26 gauge on the roof instead f the 28 gauge he uses for both roofs and sidewalls. When the project was finished, I noticed that the roofing metal seemed to be exactly the same thickness as the sidewall metal. The contractor admitted to making a mistake, and is re-roofing the structures. However, his men arrived this evening with metal that looks to me exactly the same thickness as what I already have. The workers showed me the bill of lading, which did say 16 gauge. How, exactly, can I tell what I have and what gauge the new material actually is? I am aware that the finish coating (both sides) increases the thickness of the material as does the galvalume coating itself. I put a micrometer on it and it measures 1/32 of an inch thick. The contractor's website advertises the Everlast II Traditional steel roof panels in 28 gauge steel as "28-gauge (.016) Structural Steel Grade 80 produced in conformance with ASTM792" and "True 28-gauge steel (before paint) with heavy-duty metallic coating is encased in abrasion-busting primer and Siliconized Modified Polyester topcoat to deliver enduring corrosion resistance and longer life. Wider blanks, deeper minor rib heights create a stronger, more durable panel."
Todd Miller
Isaiah Industries, Inc.
Even if the paint was removed, 0.03125" would be thicker than the industry norm for 24 gauge. I hope this helps. The gauge thickness normally stated / declared would include the galvalume or galvanized coating. (Most folks would work the numbers to include the paint finish as well.)

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