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
Homes, landlords. tenants and the new housing standards
What will it all mean?
The Architectural Technology podcast: Where it's AT
Catch-up on the latest episodes.
Edmundson Apprentice of the Year award 2026
Entries now open for this Electrical Contractors' Association award.
Traditional blue-grey slate from one of the oldest and largest UK slate quarries down in Cornwall.
There are plenty of sources with the potential to be redeveloped.
Change of use legislation breaths new life into buildings
A run down on Class MA of the General Permitted Development Order.
Solar generation in the historic environment
Success requires understanding each site in detail.
Level 6 Design, Construction and Management BSc
CIOB launches first-ever degree programme to develop the next generation of construction leaders.
Open for business as of April, with its 2026 prospectus and new pipeline of housing schemes.
The operational value of workforce health
Keeping projects moving. Incorporating unplanned absence and the importance of health, in operations.
A carbon case for indigenous slate
UK slate can offer clear embodied carbon advantages.
Costs and insolvencies mount for SMEs, despite growth
Construction sector under insolvency and wage bill pressure in part linked to National Insurance, says report.
The place for vitrified clay pipes in modern infrastructure
Why vitrified clay pipes are reclaiming their role in built projects.
Research by construction PR consultancy LMC published.
Roles and responsibilities of domestic clients
ACA Safety in Construction guide for domestic clients.
Fire door compliance in UK commercial buildings
Architect and manufacturer gives their low down.