Get even more out of a beam.
A useful measure of a beam’s efficiency is the ratio between the distance it spans and the amount of material it uses. Efficiency can be improved in several ways.
Use cantilevers. Extending a beam beyond its support helps spring the back span upward. This often allows the use of a beam with less depth than would otherwise be required. Most beams can be safely cantilevered about ⅓ the length of the back span.
Convert point loads to multiple loads. A beam more easily resists a given load if it is distributed among several locations rather than placed at one point. Moving a load from the center of a span toward one end also helps; loads from high in a building sometimes can be redistributed this way to reduce the size of beams below.
Use a truss. Although a truss must be deeper (taller) than a solid beam to do the same work, it uses a fraction of the material.
Cut holes in it. Under many loading conditions, material can be removed from the web (the vertical center portion) of a steel beam, which lightens it while allowing the passage of ducts, pipes, and wires.
