Which of the following is NOT considered a main type of scaffold?

The correct answer identifies wooden scaffolds as a type that is not categorized as a main type of scaffold in modern construction and safety standards. Instead, scaffolding typically falls under three primary categories: frame, rolling, and tube scaffolds.

Frame scaffolding consists of pre-fabricated, adjustable frames that provide a sturdy structure for workers to perform various tasks at height. Rolling scaffolds, on the other hand, are designed with wheels, allowing them to be easily moved from one location to another, increasing efficiency on the job site. Tube scaffolds use metal tubes and couplers to create a flexible and customizable structure that can be adapted to many different configurations and requirements.

While wooden scaffolds might have been used historically, they are less common today due to safety concerns and the advantages offered by metal scaffolding systems. Modern building codes and safety regulations favor the use of metal materials for their durability and strength.