High-risk construction activities and their control
Work at height
Work at Height Regulations 2005 set the order: avoid work at height where possible, prevent falls where it cannot be avoided (collective protection - guardrails, scaffolds, nets, platforms), and minimise the consequences of any fall. Fragile surfaces such as roof lights and asbestos cement sheets need protection, signage and a safe system. Ladders are not banned but are a last resort - low risk, short duration, set at 75° (1 in 4), three points of contact, secured and extending about 1 m above the landing. Scaffolds need a design or handover certificate, inspection every 7 days and after alteration or adverse weather.
Excavations
Prevent collapse and prevent falls into the trench, and locate buried services with plans plus a cable avoidance tool. Support or batter the sides, provide edge protection and toe boards, keep spoil and plant back from the edge, provide access within 25 m, and inspect by a competent person at the start of each shift and after any event.
Lifting, electricity and confined spaces
LOLER 1998: every lifting operation is planned by a competent person; thorough examination is at 6 months for accessories and equipment lifting people, 12 months for other lifting equipment. Overhead lines: follow GS6 - avoid, use goalposts, barriers and exclusion zones; never tip or slew beneath lines. Confined spaces: avoid entry, then use a safe system of work with atmospheric testing, ventilation, communications, a rescue plan and a permit.
Traps: the old "2 metre rule" no longer exists; scaffold inspection is 7 days, not 14; LOLER thorough examination is 6 months where people are lifted or for accessories; a ladder is not automatically wrong - an unsecured ladder used for a four-hour job is.
Worked example: a two-day roof repair on fragile sheets - eliminate by working from an existing platform if possible, otherwise provide collective edge and fragile-surface protection and netting beneath; harness and lanyard only as the residual layer.