10 HEALTH AND SAFETY ISSUES WHEN WORKING ON ROOFS
When working and moving about on roofs, there are several occupational health and safety issues that must be observed. These will often include:
Outdoor fall hazards
Indoor fall hazards, especially during renovations
Transport of building materials to the roof and on the roof
Heavy lifting and poor working postures
Depending on construction methods, there may also be health and safety issues arising from:
Health and safety issues depend on the work processes selected for construction, renovation, or demolition.
Health and safety issues can be mapped and mitigated by ensuring good planning in the design phase and by ensuring that health and safety is coordinated among individual contractors.
Health and safety issues can be addressed by giving serious consideration to how the building site is organised, including how to respond to fall hazards collectively (e.g., by setting up a network of guard rails and safety shields). Guard rails and safety shields must meet specific criteria in terms of dimension and strength. Fall-arrest systems can be used only when it is impossible to set up collective measures. These must only be used for approx. four hours in total. Using fall-arrest systems may be necessary when working on buildings with oblique angles, hall constructions, etc.
For renovations, it is important to consider the load-bearing capacity of the decking (particularly the battens) relative to the age and condition of the roof.
In their installation instruction, suppliers must explain how various building parts are installed (e.g., rafters and roof lights). This information must be included in the design and planning phase. It is important to remember that some components or building parts function as ’technical aids', because workmen move about on them while performing roof work.
It is important to consider how the transport of building materials to the roof and on the roof will be performed and which technical aids might facilitate such procedures.
10.1 Special Provisions for Roof Work
For work and traffic on the roof itself, there are special provisions for safety measures relative to fall hazards, depending on the roof slope. The term ‘roof’ refers to roof covering and decking for roof coverings (including battens and roofing underlayment made of wood board and sheeting). A distinction is made between roofs:
With a slope of less than 15 °
With a slope of 15 °–34 °
With a slope of 34 °–60 °
With a slope of more than 60 °
The various requirements are outlined in the WEA Guidelines Fald fra højden ved arbejde på tage (Falls From Height When Working on Roofs) (The Danish Working Environment Authority, 2014a).
For all roof pitches, preventative measures must be implemented to avoid falling off the roof if there is a special risk of falls from height or a special risk of injury caused by falls from height, regardless of the height of the roof. This may apply to both the decking, to objects on the ground, and the nature of the terrain.
Other fall hazards on the building site (e.g., connected to scaffolding work) are outlined in the WEA Guidelines Fald fra højden på byggepladser (Falls from height when working on building sites) (The Danish Working Environment Authority, 2014b). These rules also apply to structures supporting roof coverings, such as rafters and beams. There must always be safety measures in place if there is a risk of falling from height, regardless of the height above terrain.
10.1.1 Roof Pitches Below 15°
Roofs with a slope of less than 15 ° must be made safe against falls from the roof edge when the distance from roof edge to the base is more than 3.5 metres. This height can be raised to 5 metres if the roof work is carried out on a slip-resistant substrate in good wind and weather conditions.
However, this does not apply if there is a special risk of falls or of special injury resulting from falls.
10.1.2 Roof Pitches Above 15°
Safety measures to prevent falls from roof edges must be implemented when the distance from eaves to the base is more than 2 metres and when work or traffic will occur at a height of more than 5 metres above base while carrying out work.
However, this does not apply if there is a special risk of falls or of special injury resulting from falls. In such cases, safety measurement must always be implemented.
Depending on the roof slope and the vertical distance when working or moving across the roof surface, there will be additional requirements for extra protective shields in addition to roof-edge shields.
10.1.3 Trade Association Guidelines and Fact Sheets on Roof Work
Various types of roof work are subject to specific requirements laid down in trade association guidelines and fact sheets, among others, from the trade association Branchefællesskabet for arbejdsmiljø i Bygge & Anlæg (BFA) (Trade Association for Work Environment in the Building and Construction Industry) (
www.bfa-ba.dk) (formerly Branchearbejdsmiljørådet for Bygge & anlæg – BAR). Trade association guidelines and fact sheets have been reviewed by the Danish Working Environment Authority to ensure that the contents comply with occupational health and safety legislation. The content is normative for Danish Working Environment Authority inspections.
The trade association guidelines include:
Branchevejledning om tagdækning (Roofing) (BFA, 2018)
Tækkearbejde (Thatching) (BAR, 2015)
Fakta om oplægning af undertag – banevarer (Facts About Installing Roofing Underlayment – Roll Material) (BAR, 2013)
Opstilling af gitterspær (Erection of Lattice Trusses) (BAR, 2011a)
Opstilling af hanebåndsspær (montering af top på terræn A) (Erection of Attic Trusses – Installation of Ridge on Terrain A) (BAR, 2011b)
Opstilling af hanebåndsspær (montering af top efter ophejsning B) (Erection of Attic Trusses – Installation of Ridges After Being Hoisted up B) (BAR, 2011c).
Montage af saksespær (Installing Scissor Trusses) (BFA, 2017a)
Montage af bjælkespær (Installing Rafter Beams) (BFA, 2017b)
Montage af bjælkespær med kiprem (Installing Rafter Beams with Ridge Plates) (BFA, 2017c)
Montage af træelementer (Installing Wood-based Composite Slabs) (BAR, 2016)
Oplægning af beton- og tegltagsten (Installing Concrete and Clay Roof Tiles) (BAR, 2002)
Arbejde med isoleringsmaterialer (Working with Insulation Materials) (BAR, 2009).