Portal frame

Portal frame is a construction technique where vertical supports are connected to horizontal beams or trusses via fixed joints with designed-in moment-resisting capacity.

Portal frame construction is therefore typically seen in warehouses, barns and other places where large, open spaces are required at low cost and a pitched roof is acceptable.

For reasons of economy and speed, the most popular solution is some form of lightweight insulated metal cladding with cavity masonry work to the bottom 2 m of the wall to provide security and impact resistance.

The main objective of this form of design is to reduce bending moment in the beam, which allows the frame to act as one structural unit.

The transfer of stresses from the beam to the column results in rotational movement at the foundation, which can be overcome by the introduction of a pin/hinge joint.