Steel Column and Post Connections: Which Type Is Right for Your Project?

Steel posts and columns appear on structural drawings in a variety of connection configurations. Each type has a different structural purpose and a different construction detail. This article summarises the connection types you are likely to encounter on a PorthouseDean project.

Connection Type Summary

1. Goalpost Frame Beam-Column Connection

Used where a horizontal beam and vertical column are part of a portal or goalpost frame. The connection must transfer bending moment — the column and beam act together as a rigid frame to resist lateral loads or differential deflection.

This connection uses plates welded to both the beam end and the column flange, with bolts through the connection. The connection is a moment-resisting connection — not a simple pin.

See: Goalpost Frame Beam-to-Column Connection

2. Cap Plate (Beam on Top of Column)

Used where a beam sits on top of the column and the connection is simple (shear only — no moment). The cap plate is welded to the column top and the beam bears onto or is bolted to it.

Not suitable for goalpost frames. For SHS columns, a single beam centred on the column. For UC/UB columns, up to a pair of beams with each offset ≤100 mm from the column centreline.

See: Steel Column Cap Plate Details

3. UC or UB Column Base Plate

Used where a UC or UB column bears onto a pad foundation or padstone at ground or floor level. The base plate distributes the column load over a larger bearing area and provides a fixing point for holding-down bolts.

Plate thickness minimum 20 mm S275. Holding-down bolts cast into pad foundation or fixed with chemical anchors.

See: UC or UB Steel Column Base Plate Fixing Details

4. SHS Column Base Plate

Similar in principle to UC/UB base plates, but sized for the SHS column footprint. The plate typically extends beyond the SHS face to provide an adequate bolt-circle diameter for the holding-down bolt group. Contact the PorthouseDean office for the specific detail applicable to your SHS size and load.

5. UC or UB Column Wall Fixings

Where a UC or UB column runs alongside a masonry wall and must be laterally restrained by it, fixings are made through the column flanges into the wall. This provides out-of-plane restraint and load sharing.

See: How Do I Fix a Steel Column to the Wall? and UB or UC Column Wall Fixings

6. Wind Post in Cavity

A steel wind post (typically SHS or flat plate section) built into a masonry cavity wall, fixed at top and bottom to the floor structure. Used where a masonry wall panel is too slender to resist wind loads alone.

The connection at top requires special detailing at the floor/roof structure — see Understanding Windpost Connections at Gable Ends. Contact the PorthouseDean office for the specific wind post cavity connection detail.

Which Type Is on My Drawings?

The connection type for each column is stated in the element specification table on your structural drawings. If you are unsure which type applies or need clarification on the construction detail, contact us or raise a Change Request.