How to Reinforce Steel Beams

Add a Column

• 1

  Drill holes in the beam for the bolts that will connect the beam and the column. For residential use, they will typically be 9/16-inch diameter holes, so that 1/2-inch high-strength steel bolts can be used to connect the members. Drill holes in the concrete slab on the floor below the beam, and insert expansion anchors into the concrete. These pieces allow the bolts that anchor column to get a firm grip on the floor. The holes should line up perfectly with the holes in the beam. Use a level or plumb bob to check their alignment.

• 2

  Weld a base plate and a top plate onto the steel column. The plates should have holes drilled into them that line up with corresponding holes in the beam, and with the slab or floor where the column will be installed. A full penetration weld, or a groove weld with a backer plate are ideal for this application, as they create the strongest bond between metals.

• 3

  Align the column holes with the holes in the beam and the floor. Attach the members using the bolts. Tighten the bolts using a wrench. The addition of this column will add extra support along the length of the beam, and will actually decrease the stresses in each section of the beam.

Add Stiffener Plates to the Beam

• 4

  Weld stiffener plates to the bottom of the beam. By adding mass to the bottom of the beam, deflection is minimized and carrying capacity is increased. The plates can be any size, but the most efficient reinforcement occurs when the plates are the same width as the beam, and run the entire length of the beam. Typical plates measure between 1/2-inch and 1-inch thick for residential-size beams.

• 5

  Cut stiffener plates to fit the web of the beam. The web is the vertical part of the beam that connects the two horizontal pieces at the top and bottom. Cut plates approximately 2 inches shorter than the depth of the beam, so that they fit tightly against the web. They should be 2 to 3 inches in width, and 1/4 to 3/4 inches in thickness.

• 6

  Weld the plates vertically along the web at intervals of 2 to 3 feet. These pieces will increase the moment of inertia of the beam, decreasing its deflection and increasing its carrying capacity, while maintaining the same open spans as before. The increased spans of this method is one advantage over installing additional columns.