ROOFING SAFETY: HOW TO PREVENT FALLS ON ONTARIO ROOF JOBS

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Roofing is one of the most dangerous activities in construction. Falls from roofs account for a significant portion of construction fatalities in Ontario every year. Between the heights involved, the pitched and often slippery surfaces, unprotected edges, and skylights that can give way without warning, roof work presents hazards that demand serious planning and rigorous fall protection.

Under Ontario Regulation 213/91 (Construction Projects), fall protection is required at 3 metres (10 feet) — a threshold that virtually every roof job exceeds. This article covers the fall protection systems, equipment requirements, and practical precautions that keep roofers alive.

Why Roofing Falls Happen

Understanding why roofers fall is the first step to preventing it. The most common contributing factors include:

• Unprotected edges: Working near the edge of a roof without guardrails, fall arrest, or travel restraint is the single most common scenario in roofing fatalities. Workers step back to admire their work, trip on debris, or lose footing on a slope and slide off the edge.
• Fragile surfaces: Skylights, corroded metal decking, deteriorated sheathing, and fiberglass panels can look solid but will not support a worker's weight. Stepping on or near an unprotected skylight is a frequent cause of fatal falls.
• Weather conditions: Rain, frost, ice, and morning dew make roofing surfaces extremely slippery. Wind gusts can knock workers off balance, especially when carrying large sheets of material.
• Complacency: Experienced roofers who have worked at heights for years sometimes stop using fall protection because "nothing has ever happened." This attitude kills people.
• Inadequate access: Climbing on and off the roof is itself a fall hazard. Improperly set ladders, missing ladder tie-offs, and climbing onto roofs without a proper access point contribute to falls.

Guardrail Systems

Guardrails are the preferred method of fall protection on roofs because they are passive — they protect every worker in the area without requiring individual action. Under Reg. 213/91, guardrail systems on construction projects must meet specific requirements:

• Top rail height: Between 0.9 metres (3 feet) and 1.07 metres (3.5 feet) above the working surface.
• Mid rail: A mid rail is required, installed approximately midway between the top rail and the working surface.
• Strength: The guardrail system must be capable of withstanding a load of 890 newtons (200 lbs) applied at any point along the top rail in any direction.
• Toe board: A toe board at least 89 mm (3.5 inches) high is required where there is a risk of tools or materials falling off the edge.

On flat or low-slope roofs, temporary guardrail systems can be installed along the perimeter using weighted bases (no penetrations required) or clamp-on systems. On steep-slope roofs, guardrails at the eave are more difficult to install and are often supplemented or replaced by personal fall protection systems.

Personal Fall Arrest Systems

When guardrails are not practical — which is common on steep-slope residential roofing — a personal fall arrest system (PFAS) is the standard protection method. A PFAS consists of three components that must all be in place:

• Full-body harness (CSA Z259.10): The only acceptable body-holding device for fall arrest. Safety belts are not permitted. The harness must fit properly and be inspected before each use.
• Connecting device: A shock-absorbing lanyard (CSA Z259.11) or self-retracting device (CSA Z259.2.2) that connects the harness to the anchor. The connecting device must limit the maximum arresting force on the worker's body to 8 kN (1,800 lbs).
• Anchor point: Must support at least 5,000 lbs (22.2 kN) per worker or be engineered for the specific loading. On roofs, this typically means a roof anchor specifically designed and rated for fall arrest.

When using a fall arrest system on a roof, you must calculate your total fall distance to ensure there is enough clearance below the edge to arrest the fall before you hit the ground or a lower level. The fall distance calculation includes: free fall distance + shock absorber deployment (up to 1.07 metres) + harness stretch (up to 0.3 metres) + your height below the D-ring + a safety factor of at least 0.6 metres.

Always calculate your total fall distance before starting roof work with a fall arrest system. If the building is not tall enough to allow for free fall, shock absorber deployment, harness stretch, and a safety factor — a fall arrest system will not save you. Use travel restraint instead.

Travel Restraint Systems

Travel restraint is an alternative to fall arrest that prevents the worker from reaching the edge in the first place. The system uses a harness and lanyard connected to an anchor, but the lanyard length is set so the worker physically cannot get close enough to the edge to fall.

• Advantage: If a worker cannot reach the edge, they cannot fall. No fall means no fall distance calculation, no shock loading on the body, and no rescue scenario.
• Limitation: Only works when the anchor can be positioned so the lanyard length prevents the worker from reaching any edge or opening. On small roofs or near skylights, this may not be practical.
• Setup: The anchor must be positioned and the lanyard length set so that the worker cannot get closer than 0.5 metres from the edge under any circumstances. This requires careful measurement and a lanyard that cannot extend further than intended.

Travel restraint is often the better choice on flat commercial roofs where a central anchor can keep workers away from the perimeter. On pitched residential roofs, fall arrest is usually necessary because the worker needs to access the edge to install materials.

Roof Anchors

The anchor is arguably the most critical component of any roof fall protection system. A harness and lanyard are useless if the anchor fails. Roof anchors fall into several categories:

• Permanent roof anchors: Installed through the roof membrane into the structural members below. Must meet CSA Z259.15 or Z259.16 and support 5,000 lbs per worker. These are common on commercial buildings and are designed to be left in place permanently, with the roof membrane sealed around them.
• Temporary roof anchors: Designed to be installed and removed for specific jobs. Ridge-mounted anchors that straddle the peak of a residential roof are a common type. They must still meet the same strength requirements as permanent anchors.
• Engineered anchor systems: Where standard anchors are not suitable, a professional engineer can design a custom anchor system with a lower capacity, provided it is certified as part of a complete fall protection system with a specific safety factor.

Never use roof vents, plumbing stacks, satellite dishes, chimneys, or any other rooftop component as an anchor point. These are not designed to handle fall arrest loads and will fail catastrophically.

Slope Considerations

Roof slope dramatically affects both the risk of a fall and the type of protection required:

• Low slope (less than 4:12 pitch): Workers can generally stand and walk without sliding. Guardrails along the perimeter are often the primary protection, supplemented by personal fall protection near edges and openings. Warning line systems may be used in combination with other measures on large flat roofs.
• Conventional slope (4:12 to 8:12 pitch): The risk of sliding increases significantly. Personal fall arrest is typically required. Workers need to position anchors carefully and may need additional traction devices such as roof brackets (toe boards) nailed to the decking to provide footing platforms.
• Steep slope (greater than 8:12 pitch): Standing and walking on the surface is extremely difficult. Personal fall arrest is mandatory. Roof brackets and planking are essential to provide stable working platforms. Workers must be tied off at all times. The fall arrest system must account for the increased slide distance on a steep surface before the worker goes over the edge.

Skylight Protection

Skylights are one of the deadliest hazards on any roof. Many skylight covers — especially older plastic dome skylights — cannot support a worker's weight. They look solid, but a worker who steps on one will go straight through.

Under Reg. 213/91, every skylight and roof opening must be:

• Covered: With a cover capable of supporting a load of at least 2.4 kN (550 lbs) or twice the maximum expected load, whichever is greater. The cover must be secured so it cannot be accidentally displaced and clearly marked "OPENING" or "SKYLIGHT."
• Guarded: With guardrails on all sides if a cover is not installed. The guardrails must meet the same specifications as edge guardrails.
• Included in fall protection planning: Every skylight location must be identified in the fall protection plan. Workers must be made aware of every skylight on the roof before they start work.

Do not rely on the skylight itself to support any weight. Treat every skylight as an open hole unless it has been properly covered and the cover has been load-tested.

Leading Edge Work

Leading edge work — installing roofing material at the edge of a roof where no permanent edge protection exists — is among the highest-risk activities in construction. The worker is at the unprotected edge, handling materials, and often leaning or reaching.

• Fall arrest is mandatory: There is no alternative to personal fall arrest at a leading edge. Guardrails cannot be installed ahead of the work because the edge is being created as the work progresses.
• Anchor positioning: The anchor must be positioned so the fall distance calculation accounts for the maximum possible free fall. On a leading edge, the anchor is often behind and above the worker, which increases the swing distance during arrest.
• Self-retracting devices: SRDs are generally preferred over lanyards for leading edge work because they limit the free fall distance to approximately 0.6 metres (2 feet) regardless of the worker's position. Some SRDs are specifically rated for leading edge applications — check the manufacturer's specifications.

Weather Conditions

Ontario's climate creates significant additional hazards for roof work:

• Rain: Wet surfaces reduce traction dramatically. Shingle surfaces that are perfectly safe when dry become dangerously slippery when wet. Stop roof work during rain and wait until surfaces have dried.
• Frost and ice: Morning frost on a roof surface is nearly invisible and extremely slippery. In spring and fall, check roof surfaces for frost before starting work, especially on metal roofs.
• Wind: Wind gusts above 40 km/h create significant risk for workers on roofs, especially when handling large sheets of material (plywood, membrane, metal panels) that act as sails. Most roofing contractors have wind speed limits for specific activities.
• Heat: In summer, roof surfaces can exceed 65 degrees Celsius. Heat stress is a serious risk for roofers. Dehydration and heat exhaustion impair judgment and coordination, increasing fall risk.
• Lightning: Workers on a roof are the highest point in the area. Stop roof work immediately when lightning is within 10 kilometres and do not resume until 30 minutes after the last flash.

Emergency Rescue Planning

Every roof job that uses fall arrest requires a written rescue plan before work begins. This is not optional — it is required by Reg. 213/91. The rescue plan must address:

• How to reach the fallen worker: After a fall arrest on a roof, the worker may be suspended over the edge. How will the rescue team reach them? Is there a ladder, aerial lift, or other means of access?
• Equipment available: Rescue kits, additional ropes, descent devices, and first aid equipment must be identified and readily accessible before work starts.
• Time frame: Suspension trauma can incapacitate a worker within 10 to 30 minutes. Your rescue plan must get the worker down well within that window. If your plan relies on calling 911 and waiting, it is not a rescue plan — it is a hope.
• Trained personnel: At least one person on site must be trained in rescue procedures and know how to execute the plan. Practice the rescue before you start working at heights.

Roofing fatalities are preventable. The fall protection systems, equipment, and procedures exist to keep every roofer safe. The question is whether they are used — consistently, correctly, every single time. No roof is worth a life.