In scaffolding, a plank (often called a scaffold board) is a horizontal, load‑bearing component that forms the working platform on which workers stand, walk, and place materials. Planks are laid across the scaffold’s ledgers or bearers to create a safe, stable surface at various heights.

🔧 Key Characteristics & Requirements
Material

Wood – Traditionally made from species like spruce, pine, or fir. Wood planks must be graded for scaffolding use (e.g., “scaffold grade”) and free of knots, splits, or other defects.

Metal – Aluminium or steel planks are lighter (aluminium) or more durable (steel). They often have slip‑resistant surfaces and interlocking ends.

Composite / Fibreglass – Used where electrical non‑conductivity is critical (e.g., near power lines).

Dimensions

Typical thickness: 38–50 mm (1.5–2 inches).

Width: 225 mm (9 inches) is common; minimum is often 150 mm (6 inches) for walking surfaces.

Length: from 1.5 m to 4 m (5–13 ft), depending on the span between supports.

Load Rating

Planks are rated for light, medium, or heavy duty.

A single plank must support at least 4 times its intended load (factor of safety).

Overloading or spanning too far between supports can cause bending or breakage.

Safety Features

Slip resistance – Grooved, serrated, or coated surfaces reduce slipping.

End markings – Colour‑coded ends (e.g., yellow bands) indicate the plank is scaffold‑grade.

Metal reinforcement – Some wood planks have metal plates at the ends to prevent splitting.

Guardrails & toeboards – Planks alone do not prevent falls; guardrails and toeboards are required above 10 ft (3 m).

🛠️ Installation & Inspection Rules
Overlap – When using multiple planks end‑to‑end, they must overlap support points by at least 150 mm (6 inches).

Support spacing – Maximum unsupported span depends on plank thickness and load. For a 38 mm wood plank, typical max span is 1.5 m (5 ft) under light load.

No overhang – Planks should not extend beyond the end support more than 4 times their thickness (e.g., ~150 mm for a 38 mm plank) to prevent tipping.

Daily inspection – Check for cracks, warping, rot (wood), dents or corrosion (metal), and damaged anti‑slip surfaces. Defective planks must be removed immediately.

⚠️ Common Mistakes to Avoid
Using ordinary construction lumber instead of scaffold‑grade planks – never allowed.

Planks placed on unstable or missing ledgers.

Walking on planks that are wet, icy, or covered in debris.

Exceeding the rated span – a plank can snap under weight.

📋 Summary
A scaffold plank is the primary horizontal component that directly supports workers and materials. It must be made of approved materials, be correctly sized and rated, be inspected daily, and be installed according to span and overlap rules to ensure a safe working platform.