Job Hazard Analysis: Concrete cutting and coring

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 cut and locate embedded utilities

   • Cutting into energized conduit, gas lines, or post-tension cables inside the slab or wallHigh
     • Scan the cut area with GPR or X-ray and mark all conduit, rebar, and cables on the surface before cutting.
     • If the slab is post-tensioned, do not cut until the engineer or owner approves the cut location in writing.
     • Have the electrician shut off and lock out circuits running through the cut area.
     • Check both sides of walls and the floor below slabs for what could be hit or fall.

2. 2. Set up water, power, and barricades

   • Electric shock from extension cords and tools in wet slurryHigh
     • Plug every electric saw and core drill into a GFCI and test the GFCI before starting.
     • Inspect cords for cuts and missing ground prongs; tag out and remove damaged cords.
     • Hang cords up or route them away from water and slurry; keep connections off the floor.
   • Workers or public struck by falling cores or slab pieces on the floor below or other side of the wallMedium
     • Barricade and post signs on both sides of walls and below slab cuts before cutting.
     • Post a spotter or lock the area below if people could walk in.
   • Tripping over water hoses and cordsLow
     • Run hoses and cords along walls, out of walkways, and keep the work area clear of scrap.

3. 3. Anchor and run the core drill

   • Core drill spinning or kicking when the bit binds on rebarHigh
     • Bolt the drill stand with a proper anchor or use a vacuum base on smooth surfaces; check it is tight before starting.
     • Use a drill with a slip clutch and keep the bit speed right for the bit size.
     • Feed the bit slowly when you hit rebar, and never hold a stand-mounted drill by hand only.
     • No loose clothing, hanging gloves, or jewelry near the rotating bit.
   • Silica dust from drilling concreteMedium
     • Run water through the bit the whole time you drill; stop if water flow stops.
   • Core dropping out of a slab or wallMedium
     • Keep the area below barricaded and catch or secure the core before the final break-through.

4. 4. Cut the slab or wall with the saw

   • Kickback or blade failure on the handheld cutoff sawHigh
     • Use a diamond blade rated for the saw RPM; check it for cracks or missing segments before mounting.
     • Keep the blade guard in place and adjusted.
     • Hold the saw with both hands, stand to the side of the blade, and never cut above shoulder height.
     • Support the piece so the cut does not pinch the blade.
   • Respirable silica dust from sawingHigh
     • Use saws with built-in water delivery and keep enough water flowing to stop visible dust.
     • Never dry cut concrete.
     • Indoors or in enclosed areas, wear the respirator required by the company silica plan.
   • Carbon monoxide from gas-powered sawsHigh
     • Use electric or hydraulic saws indoors, in basements, and in other enclosed spaces.
     • If a gas saw must be used, open doors, run fans, and use a CO monitor.
     • Stop work and get fresh air if anyone has a headache, dizziness, or nausea.
   • Loud noise from sawsMedium
     • Keep other workers away from the saw and wear earplugs or earmuffs while saws run.

5. 5. Remove cut sections and cores

   • Cut slab or wall sections falling and crushing hands, feet, or workersHigh
     • Plan piece size so each section can be handled by your lifting equipment.
     • Shore or rig the section before the last cut so it cannot drop or tip.
     • Keep hands and feet out from under the piece and use bars, dollies, or a lift to move it.
   • Back strain lifting heavy concrete piecesMedium
     • Use a dolly, skid steer, or chain hoist; team lift anything over 50 lb.
   • Falling through new openings in floors or roofsHigh
     • Cover each hole right away with a secured cover that holds twice the expected load and mark it "HOLE" or "COVER".
     • Put guardrails around large openings or use a harness tied to an approved anchor at edges 6 ft or more above the lower level.

6. 6. Clean up slurry and demobilize

   • Slipping on wet concrete slurryMedium
     • Pick up slurry as you go with a wet vac and squeegee.
     • Wear rubber boots with slip-resistant soles.
   • Silica dust from dried slurryMedium
     • Do not dry sweep or use compressed air; use a HEPA vacuum or wet cleanup.
   • Skin burns from wet concrete slurryMedium
     • Wear waterproof gloves and wash skin with clean water right away if slurry gets on it.
     • Unplug tools before wiping them down or changing blades and bits.