The short answer
A commercial roof needs edge protection wherever people can fall from it, which means every open edge, gap and fragile area they might reach. The Work at Height Regulations 2005 favour collective measures, such as guardrails with toe boards, over personal harnesses. During works, temporary edge protection or scaffold is used. For regular visits, such as plant servicing, a permanent guardrail or parapet is better. A competent person should choose and check the system.
Why edges come first
Falls from roofs are among the most serious accidents in construction and maintenance. On a commercial building the edge can be a long way up, there may be no parapet, and the people on the roof may not be roofers at all: air-conditioning engineers, solar installers, window cleaners and building maintenance staff all visit. The Work at Height Regulations 2005 apply to all of them. The approach is a hierarchy: avoid work at height if you can, prevent falls with proper protection where you cannot, and only then reduce the consequences with nets, airbags or harnesses. In practice that means edge protection first.
Collective protection, such as a guardrail, protects everyone on the roof all the time without them having to do anything. A harness depends on each person clipping on correctly, a secure anchor point and a rescue plan. For that reason, harnesses and restraint lines are normally a last resort or an addition, not the first choice.
Types of edge protection
Temporary edge protection is used during building work. It can be a scaffold lifted above the eaves with guardrails and toe boards, a proprietary clamp-on guardrail system fixed to a parapet or steel frame, or freestanding counterweighted rails on a flat roof. A toe board stops tools and debris from rolling off the edge onto people below. Where fall heights are large, nets or soft-landing systems may be added under the roof.
Permanent protection is better where visits are regular. This can be a full-height parapet wall, a fixed guardrail along the edge, or a set-back rail system that sits behind the edge and cannot be seen from the ground. Permanent rails should be designed for the roof and checked as part of inspections, since corrosion, loose fixings and damage can weaken them. Where a rail would be too intrusive, a fall-restraint line can stop a person reaching the edge, but it needs training and equipment checks.
Fragile surfaces and openings
Edge rails also have to cope with the roof's own shape. A sloping sheeted roof needs rails along the eaves and across any gable, and a roof with a high parapet at one side and none at the other needs different treatment on each side.
Edges are not the only danger. Rooflights, old fibre-cement sheets and corroded metal sheeting can all collapse under a person's weight. Protection should cover these as well, with covers, guardrails around rooflights or netting beneath. Voids left for plant or services are another hazard, and need covers or rails until they are finished. The fragile roof safety guide goes through those risks in detail, and our note on replacing industrial rooflights shows how they are handled during a repair.
Getting on and off the roof
Edge protection is only part of safe access. People need a safe way to reach the roof: a fixed ladder with a cage or a safety gate at the top, a stair, or a hatch with a guardrail around it. An open hatch is itself a fall hazard, so it needs a rail or a cover, and a roof ladder that ends right at the edge needs a gate. Materials should be lifted by hoist or crane, never carried up a ladder. Weather matters too. Wet metal, frost and wind make any edge more dangerous, and work should stop when conditions turn.
Who decides, and what to ask for
The person in control of the work has the duty to plan it, choose suitable equipment and make sure the people using it are competent. For a building owner or facilities manager, that means asking contractors for a method statement and risk assessment before they go up, and checking that the edge protection is built by someone trained to build it and inspected regularly. If a permanent system is already fitted, it should be inspected on a schedule, and the inspection recorded, as set out in our guide to how often a commercial roof should be inspected.
If the roof has no protection and you expect regular visitors, it is worth planning a permanent system, perhaps when the roof is next renewed. A roof renewal is an ideal time, since access, anchor points and rails can be built into the new roof. See planned maintenance for commercial roofs for how access fits into upkeep.
Our free survey takes account of how your roof is reached, and we plan edge protection into every job we quote. The cost goes in the fixed written quote so it is not a surprise. The rest of our business work is on commercial roofing in Basingstoke.
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