Cantilever
A cantilever is a beam supported only at one end, with load carried over the overhang. This is in contrast to a simply-supported beam, which is supported at both ends.
Cantilevers provide a clear space underneath the beam without any supporting columns or bracing.
Cantilevers became a popular structural form with the introduction of steel and reinforced concrete. They are used extensively in building construction, notably in:
- Cantilever bridges.
- Overhanging elements and projections.
- Balconies, such as at Frank Lloyd Wright’s ‘Falling water’.
- Machinery and plant such as cranes.
- Overhanging roofs such as stadium roofs, and shelters.
- Shelving.
- Furniture.
Cantilever construction can be used in bridge building for crossing large spans. A simple cantilever span is constructed from two cantilever arms extending from opposite sides, and meeting in the middle. A common variation of this is the suspended span where the cantilever arms support a central truss bridge resting on the ends of the cantilever arms. A classic example of the cantilever bridge is the Forth Railway Bridge in Scotland which has three cantilevers with two connecting suspended spans.
Cantilever cranes (otherwise known as 'hammerhead crane') are hoisting cranes with a swing or fixed cantilever along which a hoisting trolley moves. They are often used in shipyards and during the construction of tall buildings.
[edit] Related articles on Designing Buildings Wiki
- Abutment.
- Adaptive structures.
- Arches.
- Barrel vault.
- Canopy.
- Concrete v steel.
- Conoid shell.
- Engineer.
- Folded plate construction.
- Flying buttress.
- Hyperbolic paraboloid.
- Moment.
- Pendentive dome.
- Point of contraflexure.
- Resonant column method.
- Shell roof.
- Structural engineer.
- Structural systems for offices.
- Substructure.
- Superstructure.
- Swing bridge.
- Types of beam.
Featured articles and news
The Home Energy Model and its wrappers
From SAP to HEM, EPC for MEES and FHS assessment wrappers.
Future Homes Standard Essentials launched
Future Homes Hub launches new campaign to help the homebuilding sector prepare for the implementation of new building standards.
Building Safety recap February, 2026
Our regular run-down of key building safety related events of the month.
Planning reform: draft NPPF and industry responses.
Last chance to comment on proposed changes to the NPPF.
A Regency palace of colour and sensation. Book review.
Delayed, derailed and devalued
How the UK’s planning crisis is undermining British manufacturing.
How much does it cost to build a house?
A brief run down of key considerations from a London based practice.
The need for a National construction careers campaign
Highlighted by CIOB to cut unemployment, reduce skills gap and deliver on housing and infrastructure ambitions.
AI-Driven automation; reducing time, enhancing compliance
Sustainability; not just compliance but rethinking design, material selection, and the supply chains to support them.
Climate Resilience and Adaptation In the Built Environment
New CIOB Technical Information Sheet by Colin Booth, Professor of Smart and Sustainable Infrastructure.
Turning Enquiries into Profitable Construction Projects
Founder of Develop Coaching and author of Building Your Future; Greg Wilkes shares his insights.
IHBC Signpost: Poetry from concrete
Scotland’s fascinating historic concrete and brutalist architecture with the Engine Shed.
Demonstrating that apprenticeships work for business, people and Scotland’s economy.
Scottish parents prioritise construction and apprenticeships
CIOB data released for Scottish Apprenticeship Week shows construction as top potential career path.
From a Green to a White Paper and the proposal of a General Safety Requirement for construction products.
Creativity, conservation and craft at Barley Studio. Book review.
The challenge as PFI agreements come to an end
How construction deals with inherited assets built under long-term contracts.
Skills plan for engineering and building services
Comprehensive industry report highlights persistent skills challenges across the sector.
Choosing the right design team for a D&B Contract
An architect explains the nature and needs of working within this common procurement route.
Statement from the Interim Chief Construction Advisor
Thouria Istephan; Architect and inquiry panel member outlines ongoing work, priorities and next steps.