Column Supported on a Strip Footing: When It Works and What’s Required

Not every goalpost frame column needs a separate concrete pad foundation. In some situations, the column can bear directly onto a strip footing — either the existing strip foundation beneath a wall or a new one specified for the project.

When a Strip Footing Is Sufficient

A strip footing can carry a column load if:

1. The strip footing is deep enough and wide enough to carry the combined wall load and the additional column point load without the soil bearing capacity being exceeded
2. The underbuild (the wall or masonry beneath the column base plate, sitting on the strip footing) is continuous for at least 2 metres either side of the column position
3. A padstone is specified at the column position to spread the concentrated column load into the masonry

If all three conditions are met, no separate pad is needed. The structural drawings will confirm whether the existing or proposed strip footing is adequate.

Goalpost Frames: The Strap Requirement

Goalpost frames create outward horizontal forces at the base of the columns — the “feet” of the frame tend to spread outward under load. Where columns bear onto strip footings, this spreading force must be resisted.

The solution is one of two options:

Option 1: Steel ground beam. A steel ground beam (typically the same section as the overhead beam) spans between the column feet, holding them apart and together simultaneously. This is cast into or sits on the concrete and transfers the horizontal force back across the frame.

Option 2: Steel strap. A mild steel strap — typically 150 × 8 mm — is installed between the column base plates at floor slab level, spanning horizontally to prevent the feet from spreading.

If neither of these is shown on your drawings but you have a goalpost frame, raise the question with your structural engineer before the columns are installed.

When the Strip Footing Is Too Shallow

If the existing strip foundation is at 600 mm depth but the column load requires the strip to be at 900 mm, the solution is local underpinning. The strip footing is deepened at the column position, then extended horizontally for the required length. See the article on column supported on strip footing with underpinning for the specifications.

Get Your Foundation Confirmed

PorthouseDean specifies the required foundation arrangement for all goalpost and column elements as part of the structural package. Get a quote if you need calculations for your project.