What Are Stiffener Plates?
Stiffener plates are flat steel plates welded to the web of a universal beam to prevent it from buckling under load. In portal frame buildings, stiffeners are fitted at connection points — typically at the eaves joint (where column meets rafter), the apex joint (where rafters meet at the ridge), and at base plate connections where columns meet foundations. Without stiffeners, the thin web of a UB section can deform or crush where heavy loads are concentrated, particularly at bolted end plate connections.
Every steel portal frame building needs stiffeners. They are specified on your engineer’s connection detail drawings and are a standard part of any fabrication package.
Choosing the Right Stiffener
Our stiffeners are laser-cut to match specific UB section sizes. The stiffener must match the beam it’s being welded into — the depth and width are profiled to fit snugly between the flanges.
| Your Beam Section | Stiffener to Order | Typical Plate Thickness |
|---|---|---|
| 178 x 102 x 19 UB | 178 x 102 stiffener | 8mm |
| 203 x 133 x 25 UB | 203 x 133 stiffener | 8mm |
| 203 x 133 x 30 UB | 203 x 133 stiffener | 10mm |
| 254 x 146 x 31 UB | 254 x 146 stiffener | 10mm |
| 254 x 146 x 37 UB | 254 x 146 stiffener | 10mm or 12mm |
| 305 x 165 x 40 UB | 305 x 165 stiffener | 10mm or 12mm |
Always check your engineer’s drawings for the specified thickness — this varies depending on the load the connection carries.
How Many Stiffeners Per Frame?
A typical portal frame has stiffeners at three connection points on each side:
- Eaves connection (column to rafter) — usually 2 stiffeners per joint
- Apex connection (rafter to rafter) — usually 2 stiffeners per joint
- Base plate (column to foundation) — sometimes 2 stiffeners per base
That’s roughly 8–12 stiffeners per frame. For a 6-bay agricultural shed with 7 frames, you could need 56–84 stiffeners total. Your engineer’s drawings will show the exact quantity — if you’re not sure, send us a photo of your connection details on WhatsApp and we’ll help you count.
Fitting Stiffeners
Stiffeners are shop-welded to the beam web before the steelwork goes to site. They should be fillet welded continuously on both sides of the plate. At the flange connection, the stiffener is typically sniped (trimmed at the corner) to clear the web-to-flange weld. For bearing stiffeners at base plates, the stiffener should be fitted tight to the flange to transfer the full load — your fabricator will grind the end for a flush fit.
Why Buy Stiffeners From Us?
- Buy by UB section — no need to send drawings for standard sizes
- From £1.04 per stiffener (ex. VAT)
- Laser-cut to your beam profile — accurate fit, less grinding on site
- Order before 12pm for next-day dispatch
- Buy individually — no minimum box quantities
- UK manufacturer — we cut and dispatch from our own workshop
- Need a non-standard size? WhatsApp us a drawing for a same-day quote.
Delivery Information
Next-Day Dispatch
Orders placed before 12pm (Mon–Fri) are dispatched the same day for next working day delivery (subject to courier availability).
Standard Delivery Cost
Shipping is calculated at checkout based on weight. Depending on weight or order we will send components in boxes or pallet delivery.
Packaging
All components are securely pallet-wrapped and labelled, ensuring safe and tidy arrival on-site.
Order Tracking
You’ll receive an email with tracking info once your order leaves our workshop.
Returns
We supply components made to spec, if you’ve ordered the wrong item or something’s arrived damaged, just let us know within 5 working days and we’ll sort it.
For full details, see our Returns Policy.
