Welded Cover Plate Splice: Joining Beams in Sections

When a steel beam is too long to deliver in one piece — or when site access prevents a full-length beam being manoeuvred into position — a splice allows the beam to arrive in sections and be joined on site.

A welded cover plate splice is one of the most common methods for achieving this.

How It Works

The beam is fabricated in two or more sections with a cut across the full section (web and flanges) at the splice location. At the cut point, steel plates — called cover plates — are welded across each face:

– Flange cover plates bridge the cut across the top and bottom flanges
– Web cover plates bridge the cut at the web

The plates are designed to restore the full bending, shear, and tensile continuity of the beam across the joint.

Material and Weld Specification

Cover plates are fabricated from S275 structural steel. All welds are 6 mm fillet welds, full profile — meaning the weld runs continuously along all edges of each cover plate, with no interruptions.

Welding must be carried out by a coded welder. No welding should take place near flammable materials — ensure the site area around the splice is clear of combustibles before work begins.

Inspection

A welded splice carries the same structural load as the parent section after installation. For this reason, an inspection regime is required:

– Visual inspection of all welds after completion (100% of weld length)
– Dye penetrant testing or magnetic particle inspection at the Structural Engineer’s discretion for higher-consequence applications

Economics

The welded cover plate splice is generally more economical than a bolted cover plate splice of equivalent capacity. The plates and welds are simpler to produce than pre-drilled splice plates with HSFG bolts, and there is no requirement to proof-load the bolts after tightening.

The trade-off is that a welded splice requires a qualified site welder and appropriate inspection — both of which cost money and require programme time.

Contact us if you need to discuss the splice arrangement for your project.