Scaffolding Safety Inspection

Per CSA Z797 and provincial OH&S regulations, scaffolding exceeding 10 m in height or subject to unusual loading must be designed by a professional engineer. The design must account for dead load, live load, wind load, and any imposed loads from hoisting equipment. Engineering drawings must be available on site. A competent person must review the scaffold design before erection begins.

1. Verify engineered scaffold drawings are available on site and stamped by a professional engineer where required by CSA Z797 and provincial regulations

2. Confirm the scaffold design accounts for all anticipated loads including workers, materials, wind, and any hoisting equipment

3. Check that the scaffold type (frame, tube and coupler, system scaffold) is appropriate for the application and site conditions

4. Verify the design addresses site-specific conditions including sloped ground, proximity to power lines, and adjacent traffic

5. Confirm a competent person has reviewed the design and a pre-erection meeting has been conducted with the erection crew

- Engineering drawings not obtained for scaffolds exceeding the height threshold requiring design by a professional engineer

- Wind loading not adequately addressed in the design for exposed or high-elevation scaffolds

- Scaffold design not updated when site conditions change (e.g., additional loads, modified configuration)

- Pre-erection planning meeting not conducted leaving erection crew unclear on design intent

Per CSA Z797 Clause 7 and provincial OH&S regulations, scaffold bases must be set on firm, level ground capable of supporting the imposed loads without settlement. Base plates and mudsills must be used to distribute loads. Screw jacks must be used for levelling and must not be extended beyond the manufacturer's maximum extension. The base must not be placed on unstable materials such as loose fill, ice, or frozen ground subject to thaw.

1. Verify scaffolding is erected on firm, level ground and mudsills (minimum 50 mm x 250 mm timber or equivalent) are provided under all base plates

2. Confirm base plates are installed on all standards (uprights) and are properly seated on the mudsills

3. Check that screw jacks are used for levelling and are not extended more than the manufacturer's maximum (typically 300-600 mm)

4. Verify the ground surface is adequately drained and not subject to undermining by water, excavation, or vehicle traffic

5. Confirm mudsills extend a minimum of 150 mm beyond the base plate on each side per CSA Z797

- Scaffold erected on soft or uncompacted fill settling under load causing the scaffold to become unlevel

- Base plates placed directly on soil without mudsills leading to point loads and sinking

- Screw jacks over-extended beyond manufacturer's limits reducing structural capacity

- Ground surface subject to frost heave or water erosion undermining scaffold stability

Per CSA Z797 and CSA S269.2, scaffolding must be erected by competent workers under the supervision of a competent person. All components must be from the same manufacturer and system (no mixing of systems). Components must be visually inspected for damage, corrosion, and deformation before use. Scaffold erection must follow the engineered drawings or manufacturer's erection guide.

1. Verify scaffold components are from the same manufacturer and system with no mixing of incompatible parts

2. Inspect all components for visible damage including bent tubes, cracked welds, excessive corrosion, and damaged locking mechanisms

3. Confirm scaffold is being erected in sequence per the engineered drawings or manufacturer's guide with bracing installed at each lift

4. Check that all connections (couplers, wedge pins, locks) are fully engaged and tightened to the required torque

5. Verify scaffold tubes are straight with no visible bends, dents, or wall thickness reduction from corrosion

- Components from different scaffold systems mixed together creating incompatible and unsafe connections

- Damaged or corroded scaffold tubes and frames used without inspection or rejection

- Bracing not installed at each lift during erection leaving the scaffold unstable during construction

- Locking mechanisms not fully engaged on system scaffolds due to debris or damage

Per CSA Z797 and provincial OH&S regulations, scaffold platforms must be fully decked with scaffold-grade planks or manufactured platform units. Platform width must be a minimum of 500 mm (510 mm in some provinces) for working platforms. Gaps between planks must not exceed 25 mm. Access must be provided by internal ladders, stair towers, or approved access systems. Workers must not climb scaffold frames to access work platforms.

1. Verify platforms are fully decked with no gaps exceeding 25 mm between planks and no more than 25 mm gap at the edge to the guardrail

2. Confirm platform planks are scaffold-grade lumber or manufactured metal/composite decks rated for the anticipated loads

3. Check that all planks extend a minimum of 150 mm beyond the bearer (ledger) support and are secured against displacement by wind or movement

4. Verify safe access is provided via internal ladders with rest platforms at maximum 9 m intervals or stair towers per CSA Z797

5. Confirm platform planks are free of knots, cracks, warping, and other defects that reduce load capacity

- Platform not fully decked with gaps left between planks creating fall and trip hazards

- Workers climbing scaffold frames instead of using designated ladder or stair access

- Planks not secured against displacement by wind uplift or accidental impact

- Access ladders not extending above the platform landing by a minimum of 900 mm for safe dismount

Per CSA Z797 and provincial OH&S regulations, guardrails must be installed on all open sides of scaffold platforms where workers could fall more than the height specified by the applicable provincial regulation (typically 2.4 m to 3.0 m). Guardrails must consist of a top rail at 950-1050 mm above the platform, a mid-rail, and a toeboard at least 100 mm high. Guardrails must withstand a 900 N point load per CSA Z797.

1. Verify guardrails are installed on all open sides and ends of scaffold platforms where a fall hazard exists

2. Confirm top rail height is between 950 mm and 1050 mm above the platform surface per CSA Z797

3. Check that mid-rails are installed approximately midway between the top rail and the platform

4. Verify toeboards are installed on all open sides with a minimum height of 100 mm to prevent tools and materials from falling

5. Confirm guardrail connections are secure and capable of withstanding a minimum 900 N point load applied in any direction

- Guardrails removed for material loading and not reinstalled after loading is complete

- Top rail height below minimum due to platform decking raising the working surface

- Toeboards missing allowing tools and debris to fall from the platform to workers below

- Guardrail couplers not tightened allowing rails to rotate or detach under load

Per CSA Z797 Clause 8 and provincial OH&S regulations, scaffolds must be tied to the building structure at prescribed intervals to prevent overturning and lateral displacement. Typical tie spacing is every 4 m vertically and 6 m horizontally, or per the engineered design. Ties must be connected to structurally adequate points on the building. Diagonal bracing must be installed per the manufacturer's guide or engineered drawings.

1. Verify scaffold ties are installed at the required vertical and horizontal spacing per CSA Z797 or the engineered scaffold design

2. Confirm ties are connected to structurally adequate anchorage points on the building (not to window frames, downpipes, or non-structural elements)

3. Check that all diagonal and horizontal bracing is installed per the manufacturer's guide or engineered drawings

4. Verify ties are not removed without the approval of the competent person and that compensating measures are in place where ties must be temporarily removed

5. Confirm the scaffold does not rely solely on friction or gravity to resist lateral forces (ties must be positive connections)

- Ties missing or spaced too far apart allowing the scaffold to sway or overturn in wind

- Ties connected to non-structural building elements (window frames, gutters) that cannot resist the required loads

- Diagonal bracing omitted or removed to accommodate work activities reducing scaffold stability

- Ties removed for cladding work and not replaced with compensating ties at adjacent locations