Job Hazard Analysis: Flat roof membrane (TPO/EPDM)

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. Set up ladder access, the ground zone, and hoist materials to the roof.

   • Fall from the extension ladder while climbing to the roof.High
     • Use a hoist, forklift, or conveyor for materials. Never carry rolls or boards up the ladder.
     • Set the ladder at a 4-to-1 angle, extend it at least 3 ft above the roof edge, and tie it off at the top.
     • Inspect the ladder before use. Tag out any ladder with cracked rails or broken rungs.
     • Keep 3 points of contact and face the ladder when climbing.
   • Materials falling from the roof edge or hoist onto workers below.High
     • Barricade the hoisting area and drop zone with caution tape and signs.
     • Keep everyone out from under a hoisted load. Use a tag line to control it.
     • Wear a hard hat in the ground zone and at the hoist.
   • Overloading the roof deck or rolls and boards blowing off in wind.Medium
     • Spread loads out and stage them over beams or near walls, not at mid-span.
     • Keep materials at least 6 ft back from the edge and weight down loose boards and rolls.

2. 2. Install perimeter fall protection and cover skylights and roof openings.

   • Fall from the unprotected roof edge while setting stanchions and warning line.High
     • Set the warning line at least 6 ft back from the edge, flagged every 6 ft, before other work starts.
     • Anyone between the warning line and the edge must be on a personal fall arrest system, behind guardrail, or watched by a designated safety monitor where allowed.
     • Use roof anchors rated for fall arrest and installed per the manufacturer.
   • Fall through a skylight, roof hatch, or open deck hole.High
     • Cover every skylight and hole with a cover that holds at least twice the load on it. Screw it down so it cannot shift.
     • Mark each cover 'HOLE' or 'COVER' in bright paint.
     • Never sit, stand, or step on a skylight.

3. 3. Prep the deck and install insulation boards with screws and plates.

   • Back and shoulder strain from lifting insulation bundles and membrane rolls.Medium
     • Use a roof cart or dolly to move bundles and rolls.
     • Use two people for full membrane rolls. Lift with your legs, not your back.
   • Trips over boards, fastener boxes, hoses, and cords.Medium
     • Keep walk paths clear. Run cords and hoses along the same route, away from the edge.
     • Pick up packaging and scraps as you go.
   • Heat illness from sun, hot roof surface, and reflected heat off white TPO.High
     • Start early and schedule the heaviest work for the cooler hours.
     • Provide cool water on the roof and drink a cup every 15–20 minutes. Set up shade for breaks.
     • Ease new and returning workers into full shifts in the heat. Watch each other for dizziness, cramps, or confusion.
     • Stop roof work when lightning or high wind moves in and get off the roof.

4. 4. Roll out membrane and apply bonding adhesive (fully adhered systems).

   • Breathing solvent vapors from bonding adhesive, primer, or cleaner.Medium
     • Use low-VOC or water-based adhesive when the roof spec allows it.
     • Coordinate with the owner to shut down or cover rooftop air intakes near adhesive work.
     • Read the SDS before use and keep cans closed when not pouring.
     • Work upwind. Wear the respirator the SDS calls for if vapors build up.
   • Fire from flammable solvent adhesive and its vapors.High
     • No smoking, open flames, or grinders near adhesive. Post 'No Smoking' signs.
     • Keep a charged fire extinguisher within 50 ft of the adhesive area.
     • Bring up only what you need for the day. Store extra cans closed and in the shade.
   • Wind catching unrolled membrane and pulling a worker off balance toward the edge.Medium
     • Stop unrolling sheets when wind is strong enough to lift them.
     • Weight down or fasten each sheet right after it is positioned. Never stand between a loose sheet and the edge.
   • Slips on wet adhesive, dew, or frost on the membrane.Medium
     • Plan the adhesive layout so you work toward a dry exit, not into a corner.
     • Wait for dew or frost to dry. Wear soft-soled, slip-resistant boots.

5. 5. Weld TPO seams with the hot-air welder or prime and tape EPDM seams.

   • Burns from the hot-air welder nozzle and fresh seams.Medium
     • Set hand welders on their stand when not in use. Never lay a hot welder on the membrane or insulation.
     • Let the nozzle cool before changing tips. Wear leather or heat-resistant gloves.
   • Electric shock from damaged cords, wet connections, or the generator powering the robotic welder.High
     • Plug all welders and tools into GFCI protection.
     • Inspect cords and plugs every day. Remove any with cut jackets, missing ground pins, or taped splices.
     • Keep connections out of standing water. Use heavy-duty cords sized for the welder load.
   • Fire from the hot nozzle near insulation facers, wood nailers, or adhesive vapors.Medium
     • Do not weld until adhesive solvents have flashed off.
     • Do a fire watch of welded areas before leaving the roof.

6. 6. Install edge metal, termination bar, and flashings at the perimeter and curbs.

   • Fall from the roof edge while working outside the warning line.High
     • Wear a full-body harness connected to a rated roof anchor with a lanyard or self-retracting lifeline short enough to keep you from going over.
     • Inspect the harness and lanyard before each use. Remove any with cuts, burns, or a deployed shock pack.
     • Have a rescue plan ready to reach a suspended worker within minutes.
   • Cuts from sheet metal edges, snips, and hook knives.Medium
     • Use a self-retracting utility knife where possible and cut away from your body.
     • Wear cut-resistant gloves when handling and cutting metal.
   • Flying fragments and noise from drills, pneumatic nailers, and metal cutting.Low
     • Keep tool guards in place and point nailers away from people.
     • Wear safety glasses at all times and hearing protection while using loud tools.

7. 7. Clean up, lower debris, and take down fall protection.

   • Debris thrown or blown off the roof hitting people below.High
     • Lower debris in bins with the hoist or use an enclosed chute to the dumpster. Never throw it off the roof.
     • Keep the ground zone barricaded until the roof is cleaned.
   • Fire from adhesive-soaked rags and open cans left on the roof.Medium
     • Put solvent rags in a closed metal can and remove it from the roof daily.
     • Close and lower leftover adhesive and primer cans to proper storage.
   • Fall from the edge when removing warning lines and opening covers.High
     • Remove edge protection last, while tied off to an anchor. Leave skylight covers in place until the owner says otherwise.