Structural Connections: Simple UK Guide to Types, Examples and How They Work
Structural connections are the joints that hold a building together. They link beams, columns, walls and floors so loads move safely into the foundations. This guide breaks down the main types of connections used in UK homes and explains them in simple terms.
What Structural Connections Are
Simple explanation
A structural connection is the point where two building parts meet. This includes steel beams, joists, columns and plates. The connection keeps the frame stable and stops unwanted movement.
Why they matter in UK homes
Every RSJ, loft beam or extension frame relies on proper connection design. Poorly designed joints can rotate, slip or fail.
Who designs them
A structural engineer designs the connections. The fabricator prepares the steel. The builder installs the work on site.
Rigid vs Pinned Connections
Below is a short video that explains rigid and pinned connections clearly.
What rigid means
A rigid connection stops rotation. It behaves like a fixed corner. Welded joints and stiff end plates often act as rigid joints.
What pinned means
A pinned connection can rotate slightly under load. It does not fix the beam in place for rotation. A beam sitting on a bearing plate is a common example.
Simple domestic examples
- An RSJ sitting on padstones is usually pinned
- A welded steel frame corner is often rigid
- Loft beams held with plates and bolts act like pinned connections
Main Structural Connection Types
Beam to column
Used in steel frames and larger home extensions. The beam can be bolted, welded or seated.
Beam to beam
Secondary beams often sit on the main RSJ. This is common in loft conversions and floor strengthening.
Column base
A steel column sits on a base plate fixed with bolts. It can be pinned or rigid depending on the design.
Timber to steel
Joist hangers, coach screws or angle cleats connect timber joists to steel beams.
Plate and bolt connections
Steel plates and bolts are often used when beams join at angles or carry complex loads.
Steel Connection Examples Used in UK Houses
RSJ support for wall removal
When removing a load-bearing wall, the RSJ usually rests on bearing plates or padstones. This forms a pinned connection.
Loft conversion steelwork
Loft beams often link with bolt-on plates. This supports new floors, dormers and roof loads.
Extension steel frames
Corner steel frames may need rigid joints to resist wind loads and keep the frame stable.
How Engineers Choose the Right Connection
Loads
The engineer checks how much weight the connection carries.
Bending
The engineer checks how much the beam bends under load.
Rotation
Rigid joints stop rotation. Pinned joints allow it. The engineer decides which is correct for the job.
Safety factors
Design codes add safety factors so the connection stays safe even under unusual loads.
Real UK Home Examples
Removing a load-bearing wall
The new beam sits on padstones or plates. This is a common pinned connection.
Adding a new opening
Side beams may need angle brackets or bolts to keep the frame stable.
New floor joists
Joists may sit in hangers or bolt to steel beams.
Roof spread correction
Where a roof is pushing walls outwards, rigid joints or ties may be needed to control movement.
FAQs
Is a pinned connection weak?
No. It can carry load but allows rotation.
Do all RSJs need bolts?
No. Many RSJs sit on bearing plates without bolts.
Can timber connect to steel?
Yes. Joist hangers, bolts or plates work for this.
Who checks the connections?
A structural engineer designs the connections. Building Control reviews them.
Speak to a Structural Engineer
If you need connection design for RSJs, loft beams or extensions, SECalcs can prepare the full design pack with calculations and drawings for Building Control.
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