Components
What is a sole board?
A sole board is the timber or board laid under base plates to spread a scaffold's load over the ground. It is what stops standards sinking into soft, made-up or recently disturbed ground once the scaffold is loaded.
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<img src="https://scaffoldoptix.co.uk/glossary/sole-board/diagram.svg" alt="sole board — scaffold diagram from ScaffoldOptix" width="880" height="620" loading="lazy">
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<a href="https://scaffoldoptix.co.uk/glossary/sole-board">What is a sole board?</a> — diagram by
<a href="https://scaffoldoptix.co.uk">ScaffoldOptix</a>
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</figure>Ground is the part of a scaffold nobody designs and everybody assumes. A scaffold that is perfectly built will still go out of level if one standard is stood on backfill over a drain run, and the sole board is the cheapest defence against it.
Sole boards spread load from the base plates over a larger footprint, reducing the pressure on the ground beneath. On firm, well-drained ground the requirement is lighter; on soft ground, fill, or anything recently excavated, it becomes critical — and the softer the ground the more spreading is needed.
They also give a flat bearing surface on ground that is not flat, which matters because a base plate bearing on one corner is not spreading anything.
What goes wrong on site
- No sole boards at all on ground that looks firm in dry weather and is not firm after a week of rain.
- Short offcuts under individual base plates rather than boards spanning between standards, on ground that needs the spread.
- Scaffolds erected over recently backfilled trenches, service runs or basement lights without the ground being considered at all.