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Home Glossary Universal Beam
Structural noun

Universal Beam

/YOO-ni-ver-sal beem/

Also known as: UB, I-beam, H-beam, steel joist, RSJ (colloquial), universal steel beam

A standard hot-rolled steel section with an I-shaped cross-section used as a structural beam in construction. Designated by depth and weight per metre (e.g. 254x146 UB 37), Universal Beams are the most common structural steel sections used in residential and commercial building work.

Universal Beams are specified by a structural engineer and sized to span the required opening with adequate deflection limits (typically span/360 for plaster finishes). They require adequate end bearing on a padstone and may need fire protection if they form part of a fire compartment. In residential work they commonly replace load-bearing walls or span over large openings.

Approved Document A - Structure

Steel standardBS EN 10025-2
Section standardBS 4-1 (UB sections)
Design standardEurocode 3 (BS EN 1993)
Fire protectionApproved Document B (if required)

Structural steel must be designed by a structural engineer to Eurocode 3. Section sizes are selected from the Blue Book (SCI P363). Fire resistance may require intumescent paint or board encasement.