Mueller steel building panels give you the best of both worlds: lasting color and extra strength. All of the coated panels used on Mueller's #1 steel grade buildings come with a 30-year limited paint warranty. This guarantees that the painted panels will stay fresh and vibrant for years to come. We offer many colors to fit your home and landscape. The Mueller Lock - Standing Seam panel is made of 24-gauge commercial-grade steel. The R-Panel, U-Panel and Corrugated Panels are made of 26-gauge commercial-grade steel. The panels are fire resistant, hail resistant and wind resistant up to 140 miles per hour. They also give you superior energy efficiency and durability.