Compliance & standards
What is a load class?
Load class is the classification of what a scaffold platform is built to carry. It determines how the scaffold is set out — heavier duties need shorter bays and closer standards.
A scaffold is not general-purpose. It is built for a duty, and that duty drives the geometry: the bay lengths, the number of boards, the transom spacing and how much of the platform can be loaded at once.
The practical consequence is that a scaffold erected for light access is not automatically suitable when the job changes to something heavier. The structure did not change; what is being asked of it did, and that is a design question rather than a judgement call on site.
BS EN 12811-1 defines six load classes by the service load a platform is designed to carry, from class 1 at 0.75 kN/m² up to class 6 at 6.0 kN/m². Class 1 is inspection work only; class 2, at 1.5 kN/m², covers work like painting or cleaning where no material is stored on the platform. The heavier classes are where material goes.
Knowing the classes is not the same as choosing one. Which class a scaffold is built to is a design decision that follows from what the scaffold is for, and it is set by the compliance sheet or the bespoke design rather than picked off a list.
What goes wrong on site
- A scaffold built for one duty and then used for a heavier one, which is the commonest way a compliant scaffold quietly stops being compliant.
- Material stacked on a platform that was set out for access rather than for loading.
- The duty recorded on the handover certificate from memory rather than from the design.