When designing a scaffolding structure, there are many things to consider when working out the required components. The first of which is the function of the scaffold. We will look at determining whether a light, medium or heavy duty structure is required.Firstly though, it is important to know what kind of load the structure will be required to support. In scaffolding, load is normally considered in terms of dead load and the duty live load.

The dead load generally refers to the weight of the scaffold itself. This includes the weight of the standard and all connected components such as the frames, crossbraces, planks, guardrails and attachments. The dead load increases with the height of the scaffold. Other forces such as environmental factors contribute to the dead load (water and ice for example).The duty live load considers the function of the scaffold and the loads it carries. Function is best described as the use to be made of the scaffold structure (ligh, medium or heavy duty use). The nature of the work to be performed on the scaffold is a good indicator of the duty live load. For example, a bricklayer is more likely to impose a heavier load than a painter as the weight of the bricks is much higher than some cans of paint. The live load accounts for tha materials and equipment to be used and stored on the scaffold as well as the maximum number of people working on it at any given time.

A scaffold should be designed to carry the required number of working platforms and also to support the live load.

When designing scaffolds and estimating component requirements, follow the required specifications outlined in the table below.

*Materials must not be stored on light duty working platforms that have the minimum allowable width.

Heavy Duty Scaffold

Medium Duty Scaffold

Medium Duty Scaffold

Heavy Duty Scaffold

Duty Classificationas specified inASNZS 1576.1Approximate maximumtotal load for people &materials

Kg per platform per bay

Approximate maximummass of any singleconcentrated load of

materials or equipment

(as part of total load)

 Minimum length andwidth of platform(mm) 
Light Duty*225100450
Medium Duty450150900
Heavy Duty6752001000