OHS in Roof Work and Rooftop Solar Installation

Roof work safety: which rules apply?

Factory roofs in Bursa and neighbouring provinces are no longer accessed only for gutter cleaning or cladding repair; solar power plant (GES) installation, panel maintenance and cleaning have also increased the time spent on roofs. Roof work safety requires two hazards to be addressed together: falls (from the roof edge or through a fragile surface) and electricity (the direct current produced by the panels). Which rule applies depends on the type of work:

What these three regulations have in common is the principle in Art. 5 of Law No. 6331: collective protection measures come before personal protection measures. In other words, the "whoever wears a harness can go up" approach is not enough on a roof where edge protection can be installed. We explained the general framework of work at height in our article on what work at height is; this article deals with risks specific to roofs.

Fragile roofs: the most often overlooked route to a fall

A significant share of roof accidents involve falling not from the edge but through the roof. Annex 4 of the Construction Work Regulation (B, Part II, Art. 80) therefore contains a separate provision: if workers need to work on or near a surface made of fragile material, all measures are taken to prevent them from inadvertently stepping on or falling through that surface.

Surfaces that should be treated as fragile on site are:

• Rooflights: Polycarbonate or GRP daylight panels. Often indistinguishable from sheeting because they are covered in dust.
• Old fibre cement corrugated sheets: Become brittle as they age. Since these sheets may contain asbestos in old buildings, an asbestos-suspect material assessment should be carried out before drilling or cutting.
• Corroded trapezoidal sheeting and sandwich panels: Especially around gutters and ridges.
• Roof windows, ventilation hatches and smoke vents.

On a fragile roof, the order of measures should be:

1. If possible, do the work without going onto the roof: for example, inspecting by drone or from an elevating platform, or replacing rooflights from below using scaffolding.
2. Install nets under rooflights or cover them with mesh or fixed covers.
3. Create a guarded walkway that rests on the purlins (supporting profiles); workers should cross only on this walkway.
4. Mark fragile areas on site with paint and "fragile roof, do not step" signs.
5. If these do not provide full protection, use a full body harness attached to a lifeline.

Roof edge guardrails and other collective protection

Annex 4 of the Construction Work Regulation (A, Art. 2) requires safety in work at height to be ensured first through collective protection measures such as guardrails, fall-arresting platforms, barriers, covers, working scaffolds, safety nets or air cushions. If collective protection cannot fully prevent falls or cannot be applied, a full body harness system with an anchor point or lifeline is used. The minimum requirements for temporary edge protection systems are set out in Annex 5 (B) of the regulation.

Points to consider when choosing roof edge guardrails:

• Roof pitch and cladding type: On sheet metal roofs without a parapet, systems clamped to the edge or fixed to the roof profile are used. The system's class and fixing detail should be chosen to suit the roof pitch.
• Continuity: The guardrail should extend not only around the work area but up to the material landing point and where the access ladder reaches the roof.
• Intermediate rail and toe board: Prevent a person sliding underneath and hand tools falling below.
• When it must be removed: If part of the guardrail is opened while panels are lifted onto the roof by crane, this must be covered by a permit to work, and anyone working in the open section must be attached to a lifeline.

We explained the selection of permanent lifelines and anchors in detail in our article on anchor points and lifelines. For every job on a roof where harnesses are used, a rescue plan showing how a suspended worker will be brought down should also be ready.

Solar panel installation safety: handling, loads and wind

Solar installation brings risks that differ from ordinary roof maintenance:

• Getting materials onto the roof: Panels should be lifted by crane, material hoist or elevating platform; panels should not be carried up portable ladders. Access beneath the load area is closed off.
• Roof load capacity: Panel stacks, mounting profiles and workers create point loads. Materials should not be stacked until a structural assessment has been made of stacking locations and mounting loads.
• Wind: A panel with a large surface acts like a sail in the wind and can throw the person carrying it off balance. Set the stop criterion for wind speed before starting work; details are in our article on work at height in strong wind.
• Hot and slippery surfaces: In summer, sheet metal surfaces get very hot; in winter, frost and ice in the morning hours increase the risk of slipping.
• Managing subcontractors: Solar installation is often done by a contractor. The factory's own emergency plan, roof access rules and permit to work should be communicated to the contractor before work starts.

Electrical risk in solar installations: the panel cannot be switched off

The most important characteristic of a solar panel is that it produces voltage as long as light falls on it. Switching off the inverter or the breaker on the AC side does not de-energise the DC cables between the panels and the inverter. In a string of series-connected panels, the voltage can reach hundreds of volts DC, and a DC arc is harder to extinguish than an AC arc.

Electrical work on the panel and inverter side should be carried out by persons competent in electrical installations; we explained who can do which work in our article on who can carry out electrical work. Energy isolation steps are applied using the five safety rules for electrical work; the difference in solar installations is that a "de-energised" state on the panel side can only be achieved by blocking the light or disconnecting the string.

Panel cleaning safety

Panel cleaning is the most frequent reason for going onto the roof after installation, and often the least planned. Turn the following rules into a written instruction:

1. Do not step on panels: Panels are not a walking surface. Cleaning is done from the aisles between panel rows, using long-handled equipment.
2. Check first, then water: A module showing broken glass, burn marks or a hanging cable is not wetted; the situation is reported to the person responsible for electrical work.
3. Choice of time: When the sun is high, the surface gets very hot and cold water can cause thermal stress in the glass. Plan cleaning for early morning or late afternoon.
4. Edges and fragile areas: The cleaning team must also stay within the edge protection and on the walkway. Walking backwards while pulling a hose is a typical way of approaching the roof edge.
5. Subcontractors: If cleaning is done by an outside firm, its workers' work-at-height training, health reports and PPE should be checked before work starts.

Checklist before going onto the roof

• Is the work covered by a written permit under the permit to work system?
• Have the roof cladding, rooflights and load capacity each been addressed in the risk assessment?
• Have edge protection, the walkway and rooflight protection been installed?
• Have the lifeline and anchor points been checked; have harnesses passed pre-use inspection?
• Are the rescue plan and the person responsible for it clear?
• Are the stop criteria for wind, rain and icing written down?
• Have the locations of DC isolators and the person responsible for energy isolation been identified?
• Do workers have their fitness report for work at height and their training?

We prepare the risk assessment for roof and solar work as part of our risk assessment service, and monitor permits to work and site checks through our OHS specialist services. For site-type work, see also our construction sector page.

Frequently Asked Questions

Does solar installation on a factory roof count as construction work?

Annex 1 of the Regulation on OHS in Construction Work lists installation work and electrical installation work among construction work. For solar installation, the provisions on work at height and roof work in Annex 4 of the regulation should therefore be taken into account.

Is a full body harness enough on its own on a roof?

No. Collective measures such as edge protection, walkways, nets or platforms are applied first. The harness is used when collective protection cannot fully prevent falls, attached to a suitable anchor or lifeline.

Is it safe to work on the panels once the inverter is switched off?

No. Panels produce voltage whenever they receive light; switching off the inverter does not de-energise the DC cables between the panel and the inverter. Work on the panel side is done by authorised persons, with the DC isolator opened and without separating connectors under load.

Why do rooflights need separate protection?

Rooflight panels do not bear a person's weight, and when dusty they cannot be distinguished from the roof cladding. The regulation requires measures to prevent people inadvertently stepping on fragile surfaces; nets, mesh, covers or walkways are such measures.