Long span structures

These systems incorporate facility for integration of large building services.

The merit of each of these systems depends on span, cost, degree of service integration, future adaptability etc.

Cellular beams

Perforations lighten sections and provide routes for building services.

Usual maximum span	15 m
Beam depth	Span/22

Haunched beams

Rigid connections reduce overall beam depth.

Usual maximum span	18 m
Beam depth	Span/30

Fabricated beams

Fabricated beams are usually used where long spans are required. The section is fabricated from three plates welded together to form an I-section. It is possible to design these sections with web openings to allow for service integration.

Usual maximum span	15 m
Beam depth	Span/20

Composite trusses

Trusses connected to floor slab using welded shear studs. Trusses may use tee, angle or hollow sections.

Usual maximum span	30 m
Beam depth	Span/15

Stub girders

Short beam sections are welded to the top of beams and support the floor slab. Service may pass through voids.

Usual maximum span	20 m
Beam depth	Span/15

Tapered beams

Tapered sections provide service zone adjacent to columns.

Usual maximum span	25 m
Beam depth	Span/20