An I-beam, also known as H-beam (foruniversal column, UC), w-beam (for "wide flange"), universal beam(UB), rolled steel joist (RSJ), or double-T (especially in Polish, Bulgarian,Spanish, Italian and German), is a beam with an I or H-shaped cross-section.The horizontal elements of the "I" are known as flanges, while thevertical element is termed the "web". I-beams are usually made ofstructural steel and are used in construction and civil engineering.
I beam and H beam can be found just aboutanywhere heavy duty weight support is required. They often support the mainstructure of a house and are commonly used under load bearing walls. They costmore to manufacture than a wooden beam, but provide great advantages in termsof strength.