Erection, Alteration and Dismantling of Advanced Scaffolds
Sequence and stability at every stage
A scaffold is least stable during erection and dismantling, when ties and braces are incomplete. The governing principle is that the structure must be stable at every intermediate stage, not only when complete. Erect in a planned sequence: set out and prepare foundations, place sole boards and base plates, erect standards and ledgers in lifts, install ties and braces as the lift rises rather than at the end, then deck out and fit edge protection. Dismantling is the reverse, from the top down, removing ties only as the work below permits.
Alterations
Alterations are the highest-risk activity on a live scaffold because they are often informal. Removing a tie to gain access, cutting a ledger for a doorway, or adding a spur without design input are classic failures. Any alteration affecting stability, ties or load capacity requires design confirmation and re-inspection before the scaffold returns to service.
Traps
Questions test whether ties are installed progressively or retrospectively, whether the top lift is tied, whether toe boards and guardrails are fitted before the platform is used, and whether materials are hoisted rather than thrown. Another trap is the assumption that a scaffold can be partially dismantled and left overnight without being made secure and signed off. Public protection, exclusion zones and the order of striking are also frequent question targets.
Worked rule of thumb
Use "up tied, down untied" as a memory prompt: going up, ties follow the lift immediately; coming down, ties are the last thing removed at each level. Before any break in work, apply the test: could a gust or a nudge bring this down? If yes, it is not ready to leave.
Handover
A scaffold should not be handed over for use until it is complete for its intended purpose, inspected, and tagged or otherwise recorded as fit.