Job Hazard Analysis: Scaffold erection

A general example for this task. Your JHA should reflect your crew, equipment and site — review it with a competent person before work starts.

Steps, hazards and controls

1. 1. Plan the layout and inspect the site and all scaffold parts

   • Contact with overhead power lines while raising frames or planksHigh
     • Look up and locate all overhead lines before setting the first frame.
     • If the scaffold will come within 10 ft of a line, call the utility to de-energize, move, or cover it first.
     • Assign a spotter whenever frames or planks are carried or raised near a line.
   • Damaged or mismatched frames, braces, pins, or planks causing collapseMedium
     • Inspect every frame, brace, coupling pin, and plank before use; look for bends, cracks, rust, and split wood.
     • Tag damaged parts 'Do Not Use' and set them aside.
     • Do not mix parts from different manufacturers unless the competent person approves.

2. 2. Unload and stage scaffold materials

   • Back and shoulder strain lifting 40–60 lb frames and planksMedium
     • Use a forklift or telehandler to unload bundles when available.
     • Carry frames and long planks with two workers.
     • Stage material close to where each section goes up to shorten carries.
   • Struck by vehicles or falling bundles in the staging areaMedium
     • Barricade the unloading area and post signs.
     • Stack frames and planks flat on level ground, cross-stacked and not too high.
     • Stay out from under suspended loads.
   • Pinched fingers when stacking or handling bracesLow
     • Keep hands off the ends and contact points when setting parts down.
     • Wear work gloves.

3. 3. Set the base: mudsills, base plates, screw jacks, and level the first lift

   • Scaffold settling or collapsing on soft, frozen, or uneven groundHigh
     • Set base plates on full mudsills (solid wood pads) on compacted, level ground.
     • Never use bricks, block, or loose shims to level the scaffold; use screw jacks within the manufacturer's extension limit.
     • Check plumb and level with a level before going up.
     • Keep the base away from trench edges and freshly backfilled soil.
   • Hand injuries adjusting screw jacks and base platesLow
     • Keep fingers clear of threads and the frame leg when lowering.
     • Wear work gloves.

4. 4. Erect frames and cross braces lift by lift

   • Falls from the scaffold while erecting upper liftsHigh
     • The competent person decides how erectors are protected and checks it before work starts.
     • Fully plank the lift you are standing on before raising the next frames.
     • Wear a full-body harness and tie off to an anchor the competent person approves when it is feasible.
     • Never climb cross braces; use the built-in or attached ladder.
   • Frames, braces, pins, or tools dropped on workers belowHigh
     • Barricade the area below and keep everyone not erecting out of it.
     • Raise parts with a hand line or gin wheel, not by tossing.
     • Wear a hard hat at all times.
   • Partly built scaffold tipping in high wind or stormsMedium
     • Stop erecting during high wind, storms, or lightning, and come down.
     • Install cross braces on each frame as soon as it is set, and lock all pins.

5. 5. Install planks, guardrails, toeboards, and access ladder

   • Falls through gaps or off open sides and ends of the platformHigh
     • Plank the full width of each working level with no wide gaps between planks or at the wall.
     • Install top rails at 38–45 in, midrails, and toeboards on all open sides and ends 10 ft or higher.
     • Install the access ladder or stair as the scaffold goes up.
   • Planks sliding, tipping, or breakingMedium
     • Use only scaffold-grade planks or manufacturer decks.
     • Extend planks 6 to 12 in past supports, cleat or hook them, and overlap at least 12 in over a support.
     • Never use a plank that is split, warped, or covered with dried mortar.

6. 6. Tie the scaffold to the building and set outriggers if needed

   • Scaffold tipping over from missing ties or heavy brick and block loadsHigh
     • Install ties to the structure at the spacing in the manufacturer's instructions once height is more than 4 times the base width.
     • Tie only to solid structure, never to windows, pipes, or fresh masonry.
     • Do not remove ties until the scaffold above is taken down.
   • Silica dust when drilling masonry for tie anchorsMedium
     • Use a hammer drill with a dust shroud and HEPA vacuum.
     • Wear a respirator if dust controls are not available.

7. 7. Inspect and tag the scaffold before use and each shift

   • Crew using an incomplete or overloaded scaffoldMedium
     • The competent person inspects before each shift and after any storm or impact.
     • Hang a green tag when ready and a red tag when not; no one climbs a red-tagged scaffold.
     • Know the platform load rating; stack brick, block, and mortar tubs over the frames, not mid-span.

8. 8. Clean up the area and secure leftover materials

   • Trips over loose pins, straps, and debris around the baseLow
     • Pick up pins, clips, and scraps and keep walkways clear.
     • Stack spare frames and planks in a marked storage area.
   • Tools or debris left on platforms falling laterMedium
     • Clear tools and loose items off every platform before leaving.
     • Keep barricades in place until the scaffold is tagged green.