SCAFFOLD SAFETY: WHAT EVERY ONTARIO WORKER MUST KNOW

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Scaffolds are essential on construction sites across Ontario — from high-rise builds in downtown Toronto to residential renovations in the suburbs. They provide elevated work platforms that let crews access areas that would otherwise be unreachable. But scaffolds also present serious hazards. Falls from scaffolds, scaffold collapses, and struck-by incidents involving scaffold components are responsible for a significant number of construction injuries and fatalities in this province every year.

Ontario Regulation 213/91 (Construction Projects) sets out detailed requirements for scaffold design, erection, use, and dismantling. This article covers the key rules every worker and supervisor needs to know.

Competent Persons Must Erect and Dismantle Scaffolds

Under O. Reg. 213/91, scaffolds must be erected, altered, and dismantled by or under the supervision of a competent person. This is not a vague guideline — "competent person" has a specific legal definition under the OHSA:

• Definition: A competent person is someone who is qualified because of knowledge, training, and experience to organize the work and its performance, is familiar with the OHSA and the regulations that apply to the work, and has knowledge of any potential or actual danger to health or safety in the workplace.
• What this means in practice: You cannot hand a pile of scaffold components to a couple of labourers and tell them to figure it out. The person directing the erection must understand the scaffold system being used, the manufacturer's instructions, load capacities, and the specific requirements of the regulation.
• Manufacturer's instructions: The scaffold must be erected in accordance with the manufacturer's instructions. If no instructions are available, a professional engineer must provide design drawings.

Inspection Before Each Shift

Ontario regulation requires that scaffolds be inspected by a competent person before use at the start of each work shift. This is not optional, and it is not something you can skip because "it was fine yesterday."

The inspection must check:

• Base and foundation: Mudsills or base plates must be on firm, level ground capable of supporting the scaffold and its intended loads. Settlement or erosion under the base is a red flag.
• Plumb and level: The scaffold must be plumb (vertical) and level (horizontal). Even slight leaning indicates a problem with the base or bracing that needs to be corrected before anyone gets on the scaffold.
• Bracing: All cross braces, horizontal braces, and diagonal braces must be in place and properly secured. Missing or loose bracing compromises the scaffold's structural integrity.
• Connections: All couplers, pins, locks, and connection points must be secure. Loose connections are a leading cause of scaffold collapse.
• Guardrails and toe boards: Must be in place and secure on all open sides and ends of the scaffold platform.
• Platform condition: Planks or platform decks must be in good condition, properly supported, and secured against displacement.

Guardrail Requirements

Guardrails on scaffolds are not optional decoration. O. Reg. 213/91 sets specific requirements:

• Top rail height: The top rail of a guardrail system must be between 0.9 metres (3 feet) and 1.07 metres (3.5 feet) above the platform surface.
• Mid rail: A mid rail must be installed approximately halfway between the top rail and the platform surface.
• Required on all open sides: Guardrails are required on every open side and end of a scaffold platform where a worker could fall. If the scaffold is against a wall, guardrails are still required on the outboard side and both ends.
• Strength: The guardrail system must be capable of resisting a 200-pound force applied at any point along the top rail in any outward or downward direction. Flimsy guardrails that bend when you lean on them do not meet the standard.

Never climb cross braces, end frames, or structural components to access scaffold platforms. This is one of the most common violations inspectors find — and one of the most common causes of scaffold-related falls.

Toe Board Requirements

Toe boards prevent tools, materials, and debris from falling off the scaffold platform onto workers below. They are required under the regulation:

• Minimum height: Toe boards must be at least 89 mm (3.5 inches) high, measured from the platform surface.
• No gaps: There must be no more than a 6 mm (quarter-inch) gap between the bottom of the toe board and the platform surface.
• All open sides: Required along all open sides and ends of the scaffold platform.
• Secured in place: Toe boards must be fastened so they cannot be displaced by contact or vibration.

Access Requirements

How workers get on and off the scaffold matters. Climbing the scaffold frame is not an acceptable access method.

• Ladders or stairs: Proper access must be provided — either a built-in ladder system, an attached access ladder, or scaffold stairs. The access point must be within reasonable distance of the work area.
• Ladder extension: If a ladder is used for access, it must extend at least 900 mm (3 feet) above the platform landing point.
• Access openings: If the platform has a hatch or access opening, it must be equipped with a self-closing gate or cover to prevent falls through the opening when not in use.
• No climbing the frame: Workers must not climb cross braces, end frames, or structural components to access scaffold platforms. This is one of the most common violations inspectors find, and one of the most common causes of scaffold-related falls.

Planking and Platform Requirements

The platform you stand on must be solid, stable, and properly installed:

• Full planking: The scaffold platform must be fully planked or decked across its full width. Gaps between planks must not exceed 25 mm (1 inch). Workers should never have to step over open spaces between planks.
• Overlap: Where planks overlap on a support, the overlap must be at least 300 mm (12 inches) and both planks must rest fully on the support.
• Extension beyond supports: Planks must extend at least 150 mm (6 inches) beyond their end supports, but not more than 300 mm (12 inches) unless they are secured against tipping.
• Secured against displacement: Planks must be secured so they cannot slide, shift, or be lifted by wind. Unsecured planks are a collapse and fall hazard.
• Load capacity: Scaffold planks must be capable of supporting the intended load — workers, tools, and materials — with a safety factor. Damaged, split, or weakened planks must be replaced immediately.

Load Limits and Capacity

Every scaffold has a maximum load capacity, and exceeding it is one of the leading causes of scaffold collapse:

• Rated capacity: The scaffold must not be loaded beyond the capacity specified by the manufacturer or the engineer who designed it. This capacity must be posted on the scaffold or communicated to all workers.
• Uniform vs. point loads: Understand the difference. A scaffold rated for 75 lbs per square foot as a uniform load is not rated for 1,000 lbs concentrated in one spot. Heavy equipment, material stockpiles, and mortar tubs create point loads that can exceed the platform's capacity even when the total weight is within limits.
• Do not stockpile materials: Keep only the materials you need for immediate work on the scaffold. Do not use it as a storage area.

Common Scaffold Hazards

Being aware of the most common scaffold hazards helps you identify and avoid them:

• Scaffold collapse: Usually caused by overloading, improper erection, inadequate bracing, or foundation failure. Follow the manufacturer's instructions and do not exceed load limits.
• Falls from the platform: Caused by missing guardrails, gaps in planking, or workers climbing the frame instead of using proper access. Ensure all guardrails are in place before anyone works on the platform.
• Struck-by falling objects: Tools and materials falling from scaffold platforms injure workers below. Use toe boards, debris nets, and tool tethers. Barricade the area below the scaffold if overhead work is in progress.
• Electrocution: Scaffolds erected near overhead power lines create an electrocution hazard. Ontario requires minimum approach distances from power lines based on voltage. Ensure your scaffold maintains these clearances.
• Weather: Wind, rain, ice, and snow all create additional hazards. High winds can topple scaffolds that are not properly tied to the structure. Ice makes platforms treacherous. Stop work and secure the scaffold when conditions are unsafe.
• Moving scaffolds on uneven ground: Rolling scaffolds must have all casters locked before anyone climbs on. Never move a rolling scaffold while workers are on the platform.

Scaffold Tie-Ins

Scaffolds taller than three times their minimum base dimension must be tied to the building or structure to prevent overturning. The regulation specifies:

• Tie-in spacing: Ties must be installed at regular intervals — typically every 3 metres (10 feet) vertically and every 6 metres (20 feet) horizontally, though this depends on the scaffold type and manufacturer's requirements.
• Tie strength: Each tie must be capable of resisting both tension (pulling away from the building) and compression (pushing toward the building) forces.
• No removal without replacement: Ties must not be removed unless alternative support is in place. Removing ties to accommodate work (like installing cladding) without providing replacement bracing is a serious violation.

The Bottom Line

Scaffold safety is not complicated, but it requires discipline. Erect scaffolds properly with competent supervision. Inspect before every shift. Keep guardrails, mid rails, and toe boards in place. Use proper access — never climb the frame. Do not overload the platform. And tie the scaffold to the structure when height requires it.

If your crew works on scaffolds, they need to understand both scaffold-specific safety and general fall protection. Working at Heights training covers the fundamentals of fall protection that apply every time a worker is elevated — on a scaffold, a ladder, a roof, or any other structure.