Flitch beam
The word 'flitch' refers to a plank of timber, cut lengthways from a tree trunk. It is related to the word 'flesh'.
A flitch beam is a compound beam commonly used in loft conversions and other timber-frame structures where longer spans are required than solid timber is able to provide.
Flitch beams consist of a steel plate sandwiched between two solid timber members and bolted together. Further alternating layers of timber and steel can be used as required to increase the strength of the beam.
The benefit of using flitch beams is that they are lighter and cheaper than using only steel, and allow fixing of the surrounding timber framework using nails or screws. As they are significantly stronger than timber beams they require less depth than a timber-only beam of the same strength.
In contemporary construction, the use of flitch beams has fallen into decline. This is largely due to the high cost of labour involved in their manufacture, and the introduction of high-strength engineered lumber and glulam beams. However, they can still be used to offer design versatility, and in renovation works where a structure needs to be altered or strengthened without increasing its depth or underlying construction.
[edit] Related articles on Designing Buildings
Featured articles and news
Government consultations for the summer of 2025
A year of Labour, past and present consultations on the environment, the built environment, training and tax.
CMA competitiveness probe of major housing developers
100 million affordable housing contributions committed with further consultation published.
Homes England supports Greencore Homes
42 new build affordable sustainable homes in Oxfordshire.
Zero carbon social housing: unlocking brownfield potential
Seven ZEDpod strategies for brownfield housing success.
CIOB report; a blueprint for SDGs and the built environment
Pairing the Sustainable Development Goals with projects.
Types, tests, standards and fires relating to external cladding
Brief descriptions with an extensive list of fires for review.
Latest Build UK Building Safety Regime explainer published
Key elements in one short, now updated document.
UKGBC launch the UK Climate Resilience Roadmap
First guidance of its kind on direct climate impacts for the built environment and how it can adapt.
CLC Health, Safety and Wellbeing Strategy 2025
Launched by the Minister for Industry to look at fatalities on site, improving mental health and other issues.
One of the most impressive Victorian architects. Book review.
Common Assessment Standard now with building safety
New CAS update now includes mandatory building safety questions.
RTPI leader to become new CIOB Chief Executive Officer
Dr Victoria Hills MRTPI, FICE to take over after Caroline Gumble’s departure.
Social and affordable housing, a long term plan for delivery
The “Delivering a Decade of Renewal for Social and Affordable Housing” strategy sets out future path.
A change to adoptive architecture
Effects of global weather warming on architectural detailing, material choice and human interaction.
The proposed publicly owned and backed subsidiary of Homes England, to facilitate new homes.
How big is the problem and what can we do to mitigate the effects?
Overheating guidance and tools for building designers
A number of cool guides to help with the heat.
The UK's Modern Industrial Strategy: A 10 year plan
Previous consultation criticism, current key elements and general support with some persisting reservations.
Building Safety Regulator reforms
New roles, new staff and a new fast track service pave the way for a single construction regulator.