Foundations and geotechnics

The logic of this topic

Foundations solve the task of getting the load of the structure into the ground, evenly and durably.

For a light gauge steel building this plays out along four considerations:

1. The load is small

The self-weight of the structure is a fraction of a masonry or in-situ building’s, so the pressure on the ground is lower too. That allows a smaller, cheaper foundation — on poor ground a significant saving.

2. But there is uplift

That same low weight means wind suction can pull the structure upwards. So the foundation also has to resist tension, not only compression. Resisting uplift in light structures.

3. The ground still decides

The low load does not exempt the design from a ground investigation. Settlement, swelling clay, made ground, a high water table — these affect a light building too.

4. The base junction is a building-physics junction too

This is where the wall meets the cold foundation, where the damp-proofing runs, and where the tolerances have to be taken up. Fixing the bottom track.

How to read it

Start with the ground investigation — it decides what is possible. Then the foundation types, then the ground-screw solution, which often comes up for a light structure. Finally the junction questions: frost depth, thermal bridge, moisture, radon.

What you will not find here

Specific designs and soil mechanics values. Those are produced per project, from the ground investigation report, with a geotechnical engineer.

The point

A light structure does not make geotechnics unnecessary — it just makes different questions important: less settlement, more uplift.