Steel I beams are made from 90 percent recycled steel taken from cars and appliances. The steel is melted down in an electric arc furnace, and the impurities are filtered. Chemicals are added to balance the metal's properties, and the molten material is placed into a beam mold. The mold is cooled, and then reheated, rolled and cut into the desired shape.
I beams are also produced in basic oxygen furnaces. Iron ore is melted in a coal furnace, and it is chemically treated to stabilize its properties. It is then mixed with steel scrap in the basic oxygen furnace. It is rolled into a sheet or plate. The final recycled content of I beams produced in basic oxygen furnaces is 25 percent.
Rolling is the preferred method of construction for an I beam. Rolled beams attract less moisture on the bottoms, protecting them from deterioration. Additionally, they require less maintenance, as the webs created during the beam's construction are thicker than the webs created when steel is plated.
In areas with cold winter climates, pressure wash steel I beams at least once a year to remove salt build-up. Grind out any dents in beams with an angle grinder to protect the integrity of the beam. Perform paint touch-ups and scratch repairs with epoxy and acrylic paint appropriate for industrial use.