SafetyPaperwork
HVAC · Canada

FLHA for rooftop unit replacement

By Safety PaperworkBuilt from provincial OHS law and CCOHS guidance · How we write and check theseUpdated

Provincial OHS law requires hazards to be assessed and controlled before work starts. A field level hazard assessment (FLHA) for rooftop unit replacement is done on site at the start of the shift and again whenever conditions change.

It lists the tasks, hazards and controls, and every worker signs on before starting and signs off at the end of the shift. The main hazards are falling from a roof edge, falling through a fragile roof or skylight, electric shock from live wiring and public entering the work area.

Make this FLHA nowWord templatePDF

FLHA example: rooftop unit replacement

This is a complete FLHA for rooftop unit replacement, with 6 job steps. Open it in the builder to add your site, crew and signatures, change anything, and download a PDF. Or download the free Word template below and fill it in by hand.

Field Level Hazard Assessment (FLHA)
Rooftop unit replacement · HVAC · Example
Document FLHA-001 · Rev 1

Job steps, hazards and controls

#Job stepHazardsRisk beforeControlsRisk after
1Plan the crane lift and close the area below
  • Crane and lifting failure
  • Public entering the work area
  • Contact with overhead power lines
High
  • Barricade the lift zone and keep everyone out from under the load. Engineering (guarding)
  • Use a crane rated for the load at the radius, set up on firm ground with outrigger pads. Engineering
  • Check slings, chains, shackles and hooks before use. Remove anything damaged or not tagged. Engineering
  • Plan the lift: weight, radius, ground, path and landing area. Use a written lift plan for complex lifts. Administrative
  • Use certified crane operators and trained riggers and signallers, as your province requires. Administrative
  • Fence off the site with secure temporary fencing and lock the gates when you leave. Engineering (guarding)
  • Give pedestrians a safe, marked path around the work, with ramps for strollers and wheelchairs. Engineering (guarding)
  • Use hoarding, covered walkways or catch fans where work is above public areas. Engineering
  • Put signs at each entry: site name, contact number and "No unauthorised entry". Administrative
  • Make the site safe at the end of each day: cover holes, lower buckets and booms, remove ladders and lock tools away. Administrative
  • Ask the utility to de-energize, move or insulate the lines before work starts. Elimination
  • Use non-conductive (fibreglass) ladders near any power lines. Substitution
  • Mark the safe distance with flags, tape or goal posts and keep all equipment and people outside it. Engineering (guarding)
  • Keep to the provincial limits of approach and contact the utility before working near lines. Administrative
  • Use a dedicated spotter whenever equipment moves or raises anything near lines. Administrative
  • Treat all lines as live. If equipment touches a line, stay in the cab and keep everyone well away. Administrative
Medium
2Set up roof edge protection or harness anchors
  • Falling from a roof edge
  • Falling through a fragile roof or skylight
Critical
  • Do what you can from the ground or from a scaffold at the gutter line, for example pre-assemble parts on the ground. Elimination
  • Install edge protection or guardrails on all open roof edges before work starts. Engineering (guarding)
  • Use a perimeter scaffold with handrails and toe boards along the eaves where practical. Engineering
  • Where guardrails cannot be fitted, use fall restraint on certified roof anchors so workers cannot reach the edge. Engineering
  • Use one safe, controlled access point and keep others off the roof. Administrative
  • Stop roof work in strong wind or rain, and when the roof is wet, icy or covered in dust or frost. Administrative
  • Wear a harness clipped to a rated anchor when using restraint or fall arrest, and soft-soled non-slip boots. PPE
  • Work from underneath or from an aerial work platform so nobody stands on the fragile roof. Elimination
  • Cover or guard every skylight and fragile sheet with a fixed, marked cover or mesh before work starts. Engineering (guarding)
  • Install safety mesh under new roof sheeting, and use crawl boards or staging to spread the load on fragile surfaces. Engineering
  • Use fall arrest on rated anchors when working near fragile areas. Engineering
  • Treat all roof sheets as fragile until a competent person confirms they are not. Old fibre cement and plastic sheets are fragile. Administrative
  • Put "Fragile roof" signs at every roof access point. Administrative
  • Never walk on sheets between purlins or along skylights. Stay on boards or staging. Administrative
  • Wear a full body harness clipped to a rated anchor. PPE
Medium
3Isolate power and gas, apply lockout and tags
  • Electric shock from live wiring
  • Gas and fuel lines
Critical
  • Isolate the power before any work. Do not work live. Elimination
  • Lock out and tag the isolation point with your own personal lock and danger tag. Engineering (guarding)
  • Test before you touch: prove dead at the point of work with a tested voltage tester. Engineering
  • Only licensed electricians do electrical work, to the Canadian Electrical Code and provincial rules. Administrative
  • Check for back feeds from solar, batteries and generators that can keep a circuit live after the main switch is off. Administrative
  • If energized work cannot be avoided, use a permit, a safety observer and insulated tools, following CSA Z462. Administrative
  • Wear insulated gloves, arc-rated clothing and a face shield when testing or working near live parts. PPE
  • Isolate and purge the line before work, with the owner's approval. Elimination
  • Lock off and tag the isolation valve. Engineering (guarding)
  • Check for leaks with a gas detector before and during work, and ventilate the area. Engineering
  • Only licensed gas fitters work on gas lines. Administrative
  • Remove ignition sources: no smoking, no hot work and no sparking tools near the line. Administrative
  • Know where the shut-off valve is and what to do if a leak happens. Administrative
  • Wear safety glasses and gloves, and keep a fire extinguisher close by. PPE
Medium
4Recover refrigerant before disconnecting
  • Refrigerant leaks
Medium
  • Recover refrigerant into an approved cylinder before opening the system. Never vent it. Engineering (guarding)
  • Ventilate closed spaces and use a leak detector during the work. Engineering
  • Only certified refrigeration technicians handle refrigerants, as your province requires. Administrative
  • With flammable refrigerants (such as R32 or R290), remove ignition sources and use spark-free tools. Administrative
  • Wear cold-rated gloves and safety glasses or a face shield. PPE
Low
5Lift out the old unit and set the new one, keeping clear of the load
  • Crane and lifting failure
  • Falling tools and materials
  • Strong wind and storms
High
  • Use tag lines to control loads and agree on clear radio or hand signals. Administrative
  • Stop lifting in high wind or when the operator cannot see the signaller. Administrative
  • Never ride on a load or hook. Administrative
  • Crane and lifting failure: see step 1 for the full controls Administrative
  • Barricade and sign the drop zone under overhead work so nobody walks beneath. Engineering (guarding)
  • Fit toe boards, kick plates and mesh screens on scaffolds and edges. Engineering
  • Use catch fans, debris netting or covered walkways where people pass below. Engineering
  • Tether hand tools when working at height. Engineering
  • Keep platforms tidy. Do not stack materials near edges or above toe board height. Administrative
  • Check the forecast each morning and plan work at height and lifting around the weather. Elimination
  • Tie down or weigh down loose sheets, panels, boards and rubbish at the end of each shift. Engineering
  • Set wind limits for roof work, platforms and cranes, using the manufacturer's limits, and stop when they are reached. Administrative
  • Stop work and get down in lightning. Wait 30 minutes after the last thunder before going back up. Administrative
  • Check scaffold, fencing and edge protection after strong wind before anyone uses them. Administrative
Medium
6Connect, commission and clean the roof
  • Electric shock from live wiring
  • Poor housekeeping and waste
Critical
  • Electric shock from live wiring: see step 3 for the full controls Administrative
  • Order materials to size and send packaging back where you can. Elimination
  • Put waste bins and chutes close to the work. Engineering
  • Clean as you go, and do a full clean up at the end of each day. Administrative
  • Keep exits, stairs and walkways clear at all times. Administrative
  • Stack materials neatly on level ground, away from edges. Administrative
  • Wear gloves when handling waste. PPE
Medium

PPE

CSA green triangle safety boots (CSA Z195)Hard hat (CSA Z94.1)Full body harness (fall arrest)High-visibility vest (CSA Z96)Work glovesSafety glasses (CSA Z94.3)Sun protection (sunscreen, hat, long sleeves)Rubber insulating glovesArc flash PPE (CSA Z462)Face shield

Plant and equipment

Mobile crane: Provincial crane operator certification, qualified riggerHand toolsElectrical test meterExtension ladder

Permits and plans

Lift planRoof access permitFall protection planLockout permit

Emergency

Call 911. Add the nearest hospital, the muster point and the first aid attendant for your site.

Sign-off

Supervisor and every worker sign to confirm they have read and understood this FLHA, then sign off at the end of the shift.

Free FLHA template for rooftop unit replacement

Word (.docx) and PDF, Letter landscape, no email needed. Fill in your site details, then print or send it.

Word template (.docx)PDF template

Make yours in 2 minutes

Same document, filled in for your job. Answer a few yes or no questions, the crew signs on the phone, and you send the PDF.

Start this FLHA

Pre-start checklist for rooftop unit replacement

Tick these off before work starts. They come from the hazards, permits and equipment in this job.

The safe sequence of work

  1. Plan the crane lift and close the area below
  2. Set up roof edge protection or harness anchors
  3. Isolate power and gas, apply lockout and tags
  4. Recover refrigerant before disconnecting
  5. Lift out the old unit and set the new one, keeping clear of the load
  6. Connect, commission and clean the roof

Hazards to watch on rooftop unit replacement

The hazards most specific to this job, and the step where each one comes up.

Step 4Refrigerant leaksRefrigerant gas causes frostbite, pushes oxygen out of small rooms, and some types catch fire.
Step 2Falling through a fragile roof or skylightA worker steps on a skylight, clear sheet or old fibre cement roof and falls through to the floor below.
Step 1, 5Crane and lifting failureA load falls or swings, or the crane tips, crushing workers under or near the lift.
Step 1Contact with overhead power linesA ladder, aerial work platform, crane, dump truck or long length of material touches or gets close to an overhead line and electrocutes people.
Step 3Gas and fuel linesDamaging or opening a gas or fuel line causes a leak, fire or explosion.
Step 5Strong wind and stormsWind blows sheets, panels and people off roofs and scaffolds, and storms and lightning make work at height and lifting unsafe.
Almost certainLikelyPossibleUnlikelyRareHow bad it could be: First aid only to FatalityBA
Highest risk on rooftop unit replacement: Critical before controls (B), down to Medium after controls (A), on the Canada 5 by 5 risk matrix (likely and fatality becomes unlikely and serious injury).

What changes on your site

This example covers the job itself. Your site may add more. Add controls for any of these that apply (the builder asks you these as yes or no questions):

  • Could anyone fall 3 metres or more, or fall any distance into machinery, water, a hazardous substance or through an opening?
  • Will anyone use a ladder or stepladder?
  • Will anyone work on a roof?
  • Will you use a scaffold or mobile tower?
  • Will you use an aerial work platform (scissor lift or boom lift)?

Licences and legal requirements in Canada

Equipment on this job that needs a licence, ticket or training:

  • Mobile crane: Provincial crane operator certification, qualified rigger

Employers must identify hazards before work starts and control them, and workers must be told about them. A field level hazard assessment is done on site, at the start of each shift or task, and reviewed again when conditions change.

Rules that apply: Provincial OHS regulation, cranes and hoisting; Provincial OHS regulation, fall protection; Provincial OHS regulation, electrical safety, and CSA Z462.

Why FLHAs get rejected

Prime contractors and COR auditors send documents back for these reasons. This example avoids them, but check yours too.

  • End of shift boxes already say "None" when the form was signed at the start of the shift.
  • One FLHA reused for days or weeks, or a "review by" date a month away, when the work and conditions change daily.
  • No time of assessment and no record of any revision, which Alberta s.7(3) requires.
  • Workers signed that they "read" it, but nothing shows they took part, which Alberta s.8(1) requires.
  • Work at height with no fall protection plan where the province requires one, or no written rescue procedure for workers using fall arrest.
  • Permits or locates required on site but no permit or ticket numbers recorded.
  • No re-assessment entry after an obvious change such as weather, a new task or a new crew member.

Rules by province for rooftop unit replacement

Province or territoryKey local ruleRegulator
OntarioFall protection (O. Reg. 213/91 s.26) applies at a fall of more than 3 m, more than 1.2 m where the work area is used as a path for a wheelbarrow or similar equipment, and at any height into operating machinery, water or other liquid, a hazardous substance, or through an opening.Ontario Ministry of Labour, Immigration, Training and Skills Development
British ColumbiaFall protection is required where a fall of 3 m or more may occur (s.11.2). A written fall protection plan is required at 7.5 m or more where there are no permanent guardrails (s.11.3).WorkSafeBC
AlbertaA hazard assessment must be done before work begins, and before a new work site is built (OHS Code s.7(1)). The results must be written down with the controls (s.7(2)).Alberta Occupational Health and Safety
QuebecGuardrails (Safety Code s.2.9.1, as amended by Decret 63-2025) are needed where a worker could fall into liquid or a hazardous substance, onto moving parts or dangerous equipment, 1.2 m or more when using a vehicle, 1.5 m or more when handling a load, and more than 3 m in all other cases.CNESST (Commission des normes, de l'equite, de la sante et de la securite du travail)
ManitobaA prime contractor is required whenever more than one employer or self employed person works on the site at the same time (Act s.7).Manitoba Workplace Safety and Health Branch
SaskatchewanAn occupational health committee is required at 10 or more workers of one employer (Act s.3-22).Saskatchewan Ministry of Labour Relations and Workplace Safety, OHS Division
Nova ScotiaWorkers must be trained in fall protection before using it or working in, supervising or planning work in a fall protection area, with a refresher at least every 3 years (WHSR s.21.19).Nova Scotia Department of Labour, Skills and Immigration, Safety Branch (OHS)
New BrunswickFall protection is needed from 3 m above water or the nearest permanent safe level (Reg 91-191 s.49(1)(a)(i)).WorkSafeNB
Newfoundland and LabradorGive written notice to the minister before starting a construction project that will last 30 days or more, with the site, location, type of work and number of workers (Regs s.8).Government Services, Occupational Health and Safety Division
Prince Edward IslandFall protection is needed from 3 m above the nearest safe surface or water (Fall Protection Regulations s.2(1)(a)).Workers Compensation Board of PEI, OHS Division
YukonEvery employer must do hazard assessments with the committee, representative or workers, and redo them after significant changes or incidents (Regs s.1.03.01).Yukon Workers' Safety and Compensation Board
Northwest TerritoriesFall protection is needed from 3 m, or lower if there is a risk of injury (s.119(1)). Guardrails are needed for falls of 1.2 m to 3 m at permanent work sites (s.119(2)).Workers' Safety and Compensation Commission (WSCC)
NunavutNo 911. To reach the RCMP in an emergency, dial your community's first three digits then 1111 (Iqaluit: 979-1111). Put the local fire, ambulance and RCMP numbers on every FLHA.Workers' Safety and Compensation Commission (WSCC)

Questions

Do I need an FLHA for rooftop unit replacement?

Provincial OHS law requires hazards to be assessed and controlled before work starts. A field level hazard assessment (FLHA) for rooftop unit replacement is done on site at the start of the shift and again whenever conditions change.

Who signs the FLHA?

The supervisor and every worker take part in the assessment and sign on before work starts, then sign off at the end of the shift. Review it and re-sign whenever the task or conditions change.

How long do I keep it?

Keep completed hazard assessments for at least 3 years (COR auditors sample the last 12 months). Review this FLHA and re-sign whenever the task, crew or conditions change.

What PPE is needed for rooftop unit replacement?

Usually CSA green triangle safety boots (CSA Z195), Hard hat (CSA Z94.1), Full body harness (fall arrest), High-visibility vest (CSA Z96), Work gloves, Safety glasses (CSA Z94.3), Sun protection (sunscreen, hat, long sleeves), Rubber insulating gloves, Arc flash PPE (CSA Z462), Face shield. The site rules may add more, so check with the general contractor.

More hvac FLHAs

FLHADuctless Mini Split Installation10 stepsFLHACentral Air Installation6 stepsFLHAFurnace Replacement6 stepsFLHAHVAC Maintenance5 stepsFLHADuctwork Installation5 stepsFLHARefrigerant Recovery and Regas6 steps

Related jobs in other trades

ScaffoldingScaffold ErectionAlso involves contact with overhead power linesExcavation and earthworksTrenchingAlso involves gas and fuel lines

Toolbox talks for this job

Toolbox talkOverhead Power LinesToolbox talkExtension Leads and Power ToolsToolbox talkCrane and Lifting Safety

Blank FLHA template: free FLHA templates. Also for other countries: Australia (SWMS) · United Kingdom (RAMS) · United States (JHA)

Sources