Skylights and Roof Hatches: The Underestimated Fall Hazard on Flat Roofs

Skylights, roof windows and other openings in flat roofs are among the most frequently underestimated fall hazards on industrial construction sites and during roof work. They are not always visible, are often not trafficable, and are located in areas that are accessed for other work. The accident statistics from BG BAU show: Break-ins through skylights and roof openings are one of the most common causes of death on German construction sites.

Why skylights are particularly dangerous

Plastic skylights are visually difficult to distinguish from load-bearing roof surfaces – especially in poor lighting conditions or when they are dirty. Even when recognized as such, workers often make incorrect distinctions: A skylight appears stable but generally does not bear weight. Break-ins happen without warning.

In addition: Skylights are often located in areas where work is carried out – specifically near air conditioning units, ventilation devices or other maintenance-intensive installations.

Safety measures for skylights and roof openings

DGUV Information 201-056 requires that all non-trafficable areas on roof surfaces be marked and secured. This explicitly applies to skylights and roof windows.

Possible measures:

Protective grilles and gratings: Load-bearing grilles that are placed over the skylight or attached to it. They must withstand a surface load of at least 1.5 kN/m². No net, no light grille – but a load-bearing grating.

Perimeter with side protection: A railing around the skylight prevents stepping into it. This solution is particularly suitable if the skylight is not to be completely covered.

Marking: Even where physical securing is not possible – for example, with very large skylights – the fall hazard must be clearly marked. However, this does not replace physical securing if work is taking place nearby.

Trafficable vs. non-trafficable surfaces

Not every surface on a flat roof is equally dangerous. A distinction is made between trafficable surfaces (e.g., concrete, trapezoidal sheet metal with sufficient support) and non-trafficable surfaces (skylights, thin corrugated iron coverings, older roof membranes in poor condition). The danger often lies in the fact that the difference is not recognizable from the outside.

Checklist: Check before roof work

• Are there skylights, roof windows or other openings on the roof surface?
• Are they trafficable? (If in doubt: assume no)
• Are they sufficiently secured or covered?
• Are the safety measures documented in the risk assessment?
• Have all employees been instructed about the location of hazardous areas?

Supplement fall protection

Securing skylights supplements collective side protection – it does not replace it. For roof edges and perimeter areas, roof edge protection is still necessary. Mobile anchors can be used in areas where complete side protection is not feasible.

Gerüstexpress advises you on planning complete roof protection that covers roof edges, openings, and special areas equally. Request a consultation now.

Frequently asked questions

Are skylights generally not load-bearing?

As a rule, no. Plastic skylights are not designed for personal loads and break when stepped on. Exceptions exist but must be proven by the manufacturer.

What should I do if I go on a roof with skylights for the first time?

First, determine the location and number of skylights, then plan and implement the safety measures before anyone enters the roof surface. Do not rely on the openings still being secured from previous work.

Do I also have to secure skylights if I am not working nearby?

Yes. If the roof surface is entered, all non-trafficable areas must be secured – regardless of whether work is being carried out directly on them.