Goalpost Frame Beam-to-Column Connection: How It Works

A goalpost frame is the structural arrangement used when removing a load-bearing wall that also needs to provide lateral stability to the building. Unlike a simple beam on padstones, a goalpost frame connects the beam end rigidly to the column top, creating a moment-resisting portal frame.

Why a Moment Connection Is Needed

In a standard beam installation, the beam ends simply rest on padstones and carry vertical load. The beam cannot resist sideways forces — it has no means of transferring moment (rotational force) to its supports.

In a goalpost frame, the building’s lateral stability relies on the frame resisting wind-induced sway. This requires the connection between the beam and each column to be stiff enough to prevent the joint from rotating under load. A flexible end plate alone is insufficient for this — a full moment connection with stiffeners is needed.

Standard Connection Elements

For a typical PorthouseDean goalpost frame, the connection between the beam end and the column head contains:

– Full-depth end plate welded to the beam end — thicker than a standard shear plate (often 20–25 mm for larger frames)
– Column stiffener plates welded between the column flanges at the level of the beam top and bottom flanges — these direct the beam flange forces into the column section efficiently
– Grade 8.8 black bolts in a pattern sized to resist the design moment and shear

Specific plate thicknesses, bolt sizes and spacing are set in the calculations for each project and shown in the structural drawings. These are not generic — they must be followed precisely.

Standard Materials

– All plates: S275 mild steel unless noted otherwise
– All welds: 8 mm full profile fillet weld (heavier than a standard connection due to the moment demand)
– All bolts: Grade 8.8 black
– All beam/column steelwork: Grade S355 unless noted otherwise

Checking the Base Plate

For the connection at the foot of each column, see the UB or UC steel column base plate fixing details article. The base plate anchors the column to its foundation and completes the frame by providing moment resistance at both ends of the column.

Temporary Stability

Columns must be braced in the temporary condition during construction. Until the beam is connected and the floor or roof structure provides lateral restraint at the head, the columns are free-standing and at risk of overturning. Temporary works propping is the contractor’s responsibility.

Get Your Goalpost Frame Designed

PorthouseDean designs goalpost frames for large openings and extensions across England and Wales. Get a quote to start your structural calculations.