Joist bridging
The term 'bridging' refers to a brace, or an arrangement of braces, that is fixed between floor or roof joists to keep them in place, prevent joist rotation, and distributing loads over more than one joist. Other, similar terms include 'nogging' and 'dwang'.
Bridging can help strengthen a floor and stop it from bouncing when occupants walk across it. By bridging, each joist shares load with the one/s next to it, which can help reduce deflection by as much as half.
There are a number of different bridging techniques that can be used. Solid bridging involves joist-depth timber being installed perpendicular to and between the joists. Cross-bridging involves an ‘X’ being formed between joists by pairs by braces (also known as herringbone struts).
If a floor has bridging running down the centre already, it can be stiffened further by adding additional rows on either side. The bridging that is already in place should be fastened tightly using additional nails or screws. A good rule-of-thumb is that the span of the joists should be measured and then divided by three, with rows of bridging then placed at both of the one-third points.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
First aid in the modern workplace with St John Ambulance.
Ireland's National Residential Retrofit Plan
Staged initiatives introduced step by step.
Solar panels, pitched roofs and risk of fire spread
60% increase in solar panel fires prompts tests and installation warnings.
Modernising heat networks with Heat interface unit
Why HIUs hold the key to efficiency upgrades.
Reflecting on the work of the CIOB Academy
Looking back on 2025 and where it's going next.
Procurement in construction: Knowledge hub
Brief, overview, key articles and over 1000 more covering procurement.
Sir John Betjeman’s love of Victorian church architecture.
Exchange for Change for UK deposit return scheme
The UK Deposit Management Organisation established to deliver Deposit Return Scheme unveils trading name.
A guide to integrating heat pumps
As the Future Homes Standard approaches Future Homes Hub publishes hints and tips for Architects and Architectural Technologists.
BSR as a standalone body; statements, key roles, context
Statements from key figures in key and changing roles.
ECA launches Welsh Election Manifesto
ECA calls on political parties at 100 day milestone to the Senedd elections.
Resident engagement as the key to successful retrofits
Retrofit is about people, not just buildings, from early starts to beyond handover.
Plastic, recycling and its symbol
Student competition winning, M.C.Esher inspired Möbius strip design symbolising continuity within a finite entity.
Do you take the lead in a circular construction economy?
Help us develop and expand this wiki as a resource for academia and industry alike.
Warm Homes Plan Workforce Taskforce
Risks of undermining UK’s energy transition due to lack of electrotechnical industry representation, says ECA.
Cost Optimal Domestic Electrification CODE
Modelling retrofits only on costs that directly impact the consumer: upfront cost of equipment, energy costs and maintenance costs.
The Warm Homes Plan details released
What's new and what is not, with industry reactions.