Job Hazard Analysis: Deck construction

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. Lay out the deck, confirm utility locates, and set up power and tools.

   • Hitting buried gas, electric, or water lines when digging.High
     • Call 811 before digging and wait for all lines to be marked.
     • Move footing locations away from marked lines when the design allows.
     • Hand dig within 18 in. of any marked line.
   • Electric shock from damaged extension cords or ungrounded outlets.Medium
     • Plug all tools into a GFCI outlet or portable GFCI.
     • Inspect cords before use; tag out and remove any with cuts or missing ground pins.
     • Keep cords out of puddles and off walkways.
   • Contact with overhead power lines when carrying long lumber or ladders.High
     • Locate the service drop and overhead lines before work starts and point them out to the crew.
     • Keep ladders, lumber, and tools at least 10 ft from power lines.
     • Use fiberglass ladders only.

2. 2. Dig footing holes and pour concrete footings.

   • Power auger kickback or twisting when the bit hits a rock or root.Medium
     • Use a towable or frame-mounted auger with a torque arm instead of a handheld one when possible.
     • Run handheld augers with two workers, feet planted, and the kill switch within reach.
     • Keep loose clothing and gloves away from the spinning bit.
   • Chemical burns to skin and eyes from wet concrete.Medium
     • Mix in a wheelbarrow or mixer, not by hand.
     • Keep clean water on site to rinse skin and eyes right away.
     • Wear alkali-resistant gloves, safety glasses, and long sleeves; wash off any concrete on skin.
   • Back strain from lifting 60-80 lb concrete bags.Medium
     • Use a hand truck or wheelbarrow to move bags.
     • Lift with your legs and get help for heavy loads.
   • Tripping or twisting an ankle in open holes.Low
     • Cover or flag open holes until they are poured.

3. 3. Install the ledger board on the house and set the posts.

   • Fall from a ladder while installing the ledger.Medium
     • Work from a rolling platform or scaffold instead of a ladder when the ledger is long or high.
     • Set extension ladders at a 4-to-1 angle on firm, level ground; open stepladders fully and lock the spreaders.
     • Keep three points of contact and do not stand on the top two steps.
   • Drilling into hidden wiring or plumbing inside the house wall.Medium
     • Check inside the house for panels, outlets, and pipes behind the ledger line before drilling.
     • Shut off the circuit at the panel if wiring is near the drilling area.
   • Posts or a heavy ledger falling on workers before they are braced.Medium
     • Brace each post in two directions right after setting it.
     • Use two workers to lift and hold the ledger while it is fastened.

4. 4. Frame the beams and joists.

   • Falling 6 ft or more while walking on beams or open joists.High
     • Build as much framing as possible from the ground, then raise it into place.
     • Install temporary guardrails on open sides, or use a personal fall arrest system tied to a rated anchor.
     • Lay temporary plywood over joists for a work surface; do not walk the top of joists.
   • Nail gun puncture wounds from accidental firing or nails passing through wood.High
     • Use full sequential trigger nailers only.
     • Keep your free hand at least 12 in. from the nailing point and never point the nailer at anyone.
     • Disconnect the air hose before clearing jams, moving, or handing off the nailer.
     • Wear safety glasses at all times when nailing.
   • Being struck by dropped lumber, hangers, or tools from above.Medium
     • Keep workers out from under overhead framing work.
     • Wear a hard hat when anyone is working overhead.

5. 5. Cut and install the deck boards.

   • Cuts and kickback from the circular saw.High
     • Make repeat cuts on a miter saw with a stand when possible.
     • Check that the lower blade guard returns freely; never pin it back.
     • Support boards on both sides of the cut and keep your body out of the blade line.
     • Unplug the saw before changing blades.
   • Falling off the open edge of the deck.High
     • Keep temporary guardrails in place on open sides 6 ft or more above grade until permanent railings are installed.
     • Work facing the edge, not backing toward it.
   • Wood dust, splinters, and noise from cutting treated or composite boards.Low
     • Cut outdoors downwind of the crew and use saws with dust bags when available.
     • Wear gloves, safety glasses, hearing protection, and a dust mask when cutting.
     • Wash hands before eating after handling treated lumber.
   • Knee and back strain from kneeling and bending.Low
     • Rotate tasks and take short stretch breaks.
     • Wear knee pads.

6. 6. Build the stairs and install the railings.

   • Falling from the deck edge or stair opening before railings are complete.High
     • Remove temporary guardrails one section at a time only as permanent rail goes in.
     • Barricade the stair opening until stairs and handrails are installed.
     • Use fall arrest when working outside the rail line at 6 ft or more.
   • Cuts from the miter saw when cutting balusters and stringers.Medium
     • Clamp short pieces; keep hands at least 6 in. from the blade.
     • Let the blade stop fully before raising it.
   • Ladder tip-over on uneven ground near the stairs.Medium
     • Level the ground or use ladder levelers; never stack blocks under ladder feet.

7. 7. Clean up the site and store tools and materials.

   • Stepping on nails or tripping over scrap lumber and cords.Medium
     • Pick up scrap and bent nails throughout the day, not just at the end.
     • Sweep the area with a magnet for loose nails and screws.
     • Coil cords and hoses and keep paths clear.
   • Lumber stacks falling over.Low
     • Stack lumber on level blocking, crossed or banded, no higher than you can safely reach.