Fragile Roofs And Surfaces
Work on or near fragile surfaces is also covered by the Work at Height Regulations. Roof work, particularly work on pitched roofs, is hazardous and requires a specific risk assessment and method statement for a definition of a method statement) prior to the commencement of work. Particular hazards are fragile roofing materials, including those materials which deteriorate and become more brittle with age and exposure to sunlight, exposed edges, unsafe access equipment, and falls from girders, ridges, or purlins. There must be suitable means of access such as scaffolding, ladders, and crawling boards; suitable barriers, guard rails, or covers where people work near fragile materials and roof lights; and suitable warning signs indicating that a roof is fragile should be on display at ground level.
Where possible, work on a fragile roof should be avoided by doing the following:
- work from underneath the roof using a suitable work platform or
- where this is not possible, use a mobile elevating work platform that allows people to work from within the basket without having to stand on the roof.
If access onto the fragile roof cannot be avoided, perimeter edge protection should be installed and staging used to spread the load. Unless all the work and access is on staging or platforms that are fitted with guard rails then safety nets should be installed underneath the roof or a harness system used. Where a harness is used, adequate anchorage points will be required.
A roof should always be treated as fragile until a competent person has ruled otherwise. Fragility can be caused by:
- general deterioration of the roof through ageing, neglect, and lack of maintenance;
- corrosion of cladding and fixings;
- quality of the original installation and selection of materials;
- thermal and impact damage;
- deterioration of the supporting structure; and
- weather damage
Asbestos cement sheets and old roof lights should always be treated as fragile.
There are other hazards associated with roof work – overhead services and obstructions, the presence of asbestos or other hazardous substances, the use of equipment such as gas cylinders and bitumen boilers, and manual handling hazards.
All roofs, once fixed, should be treated as fragile until a competent person has confirmed that they are nonfragile. In particular, the following are likely to be fragile:
- fiber-cement sheets – non-reinforced sheets irrespective of profile type;
- liner panels – on built-up sheeted roofs;
- metal sheets – where corroded;
- glass – including wired glass;
- chipboard – or similar material where rotted; and
- roof lights.
It is essential that only trained and competent persons are allowed to work on roofs and that they wear footwear having a good grip. It is a good practice to ensure that a person does not work alone on a roof. Guidance from the Advisory Committee for Roof Work states that any person undertaking roof work needs to be ‘both mentally and physically fit, competent to do the work, and be fully aware of all the dangers that exist and the actions necessary to overcome those dangers’. The HSE has published the third edition of the guidance booklet on safety during roof work – HSG33, Health, and safety in roof work.
A roof ladder should only be used if more suitable equipment cannot be used and should only be used for low-risk, short-duration work. Roof ladders should be of an industrial-grade, in good condition, and secured to prevent movement. The anchorage at the top of the roof ladder should be by some method that does not depend on the ridge capping, as this is liable to break away from the ridge. The anchorage should bear on the opposite slope by a properly designed and manufactured ridge hook or be secured by other means.
Roof work should not be attempted in poor weather conditions such as rain, ice, frost, or strong winds (particularly gusting) or if slippery conditions exist on the roof. Winds in excess of 23mph (Force 5) will affect the balance of a roof worker.