| Fall from height from the roof pitch, eaves, verges or scaffold lift while carrying out PV installation | Operatives. A fall can cause fatal or life-changing injuries. | Independent scaffold with double guardrails at eaves and ladder access bay, supplied by others. Operatives trained in working at height. | 3×5=15 | Avoid roof work where possible by assembling and staging materials from the scaffold. Check the scaffold edge protection extends to the verges and covers the roof pitch and slope length. If it does not, stop and get the scaffolder to add measures before roof work begins. No one goes onto the roof pitch without the roof ladder correctly hooked over the ridge or secured and without a second operative present. Work planned and carried out in line with the Work at Height Regulations 2005. No operative works alone on the roof. Keep the scaffold boards clear and never lean over guardrails. Safety footwear with good grip (EN ISO 20345) and a helmet with chinstrap as the last line of defence. | Medium |
| Scaffold defects or unauthorised alteration (scaffold supplied by others) | Operatives and anyone below if the scaffold fails or a guardrail is missing. | Scaffold handover certificate from the scaffolder. | 2×5=10 | Check the handover certificate and carry out a visual check before use on both days, including ties, boards, guardrails, toe boards and the ladder bay. Do not remove or move any scaffold component. If anything needs changing, ask the scaffolder. Confirm the scaffold is inspected as required by the Work at Height Regulations 2005. Tag as not in use and stop work if defects are found. | Medium |
| Slips and trips on roof tiles and roof ladder, including wet, moss-covered or loose tiles, and access onto and off the pitch | Operatives. Falls on the pitch, or when stepping on or off the scaffold, can cause serious injury. | Roof ladder or cat ladder for pitch access, scaffold ladder bay, trained operatives. | 3×4=12 | Inspect the roof for loose tiles, moss and fragile areas such as rooflights before stepping onto it. Mark any fragile areas and keep clear of them. Walk on the roof ladder or on crawling boards and keep three points of contact when moving. Only work on the pitch when it is dry. Keep the working area tidy of offcuts, packaging and cable. Safety footwear with good grip (EN ISO 20345) as backup. | Medium |
| Falling objects such as tools, tiles, rails, fixings or a module dropped from the roof or scaffold | Operatives, household members, neighbours, passing public and other trades below. A strike can cause serious head injury or death. | Scaffold toe boards. Barriers at ground level. | 3×4=12 | Set an exclusion zone at ground level below the work area before work starts, with barriers and signs. Check the scaffold brickguards and netting or debris protection if the scaffolder provides it. Keep tools in tool bags with lanyards where used on the roof, and do not leave anything loose on the pitch or the scaffold edge. Lower waste in a bag or container, never throw it. Hard hats worn by all on the scaffold and roof (EN 397 with chinstrap) as backup. | Medium |
| Manual handling of PV modules, rails and inverter, including up the scaffold and on the pitch | Operatives. Back, shoulder and hand injuries, and dropping a module while overbalanced at height. | Three operatives. Trained in manual handling. | 4×3=12 | Follow the Manual Handling Operations Regulations 1992. Use two people for each module, carry them on edge and keep them flat when working out of the wind. Stage materials on the scaffold with a hoist or ladder lift where possible so lifting from ground to roof is not by hand over guardrails. Check module weights and size on delivery and plan the carry route. Take rest breaks and rotate the heavy tasks. Gloves with good grip as backup. | Medium |
| Wind, rain, cold and sun exposure, with modules acting as sails in gusts and wet roof surfaces | Operatives on the roof and anyone below if a module is blown or dropped. Heat and cold stress. | Weather forecast check. Supervisor decides on starting. | 3×4=12 | Check the forecast at the pre-start and again at each break. Do not carry or fit modules in gusty conditions. Stop roof work in rain, ice, lightning or high wind, secure materials and leave the roof. Keep modules secured as soon as they are placed. Provide shade, drinking water and warm drinks in the vehicle. Sun cream, suitable layers and waterproofs as backup. | Medium |
| Electric shock from live DC string cabling and modules. Modules produce voltage whenever there is daylight and cannot be switched off. | Operatives. Electric shock, burns or a fall caused by a shock reaction. | Double-insulated DC cabling, DC isolator, MCS accredited installers with 18th Edition and PV Code of Practice training. | 3×5=15 | Work to the Electricity at Work Regulations 1989, BS 7671 Section 712 and the IET Code of Practice for Grid-connected Solar PV. Keep modules face-down or covered until they are ready to connect. Make the string connections last, with the DC isolator open and with the inverter not yet energised. Use matching MC4 connectors and the correct crimp tool. Keep the strings short-circuit and open-circuit voltage readings on the test sheet. Never disconnect a loaded string. Use a DC-rated meter with GS38 compliant leads. Insulating gloves and insulated tools where live DC parts could be touched. | Medium |
| Live AC services: work at the existing consumer unit and AC cabling, with the supply interrupted for the household | Operatives, and household members if a circuit is energised during the work or by being left without power. | Electrical isolation permit for the AC side. Competent electricians with 18th Edition. | 3×5=15 | Work under the Electricity at Work Regulations 1989 and BS 7671. Safe isolation with a lock-off and tag, proving dead with a GS38 compliant tester and proving unit before and after. Only the person who locked off removes the lock. Tell Ms Bramley the time and extent of the power cut and agree arrangements for any vulnerable people, fridges and medical equipment. No live working. Test and certify before re-energising, and make sure the inverter cannot back-feed the supply when the AC is isolated. | Medium |
| Arcing, overheating and fire from poor MC4 connections, damaged cable or mismatched connectors | Operatives, the household and neighbours. Fire in the roof space or on the array. | Double-insulated cable, correct tools, trained installers. | 2×4=8 | Use only matching MC4 connectors and the correct crimp tool, check each crimp and pull test it. Route and clip the cable clear of sharp edges and tile contact and avoid tight bends. Carry out insulation resistance and polarity tests before energising. Have a suitable extinguisher in the vehicle for incipient fire only. Record faults found. If a fire cannot be put out with an extinguisher, evacuate and call 999, telling the fire service there is a PV system, because the DC side stays live in daylight. | Low |
| Occupied site: the household (Ms Bramley, family members, visitors and pets) living in the house during the works | Household members, who could be struck by falling objects, come into contact with tools, cables or the scaffold, or be affected by an interrupted power supply. | Client contact. Work is on the roof and exterior. | 3×3=9 | Agree with Ms Bramley at the pre-start which areas are out of bounds and keep household members and pets away from the scaffold, the drop zone and the van area. Barrier the zone off, keep it tidy and lock away tools and materials at the end of each day. Keep the supply interruption to the shortest time needed and warn the household in advance. Keep the ladder access closed off to the household and children and do not leave ladders resting where someone could climb them. Tell the household which route to the WC is used and keep it clear of the work. | Low |
| Public and other trades nearby: pedestrians and neighbours near the property, and the scaffolders and any other trades using the scaffold or the surrounding space | Passers-by, neighbours, children and other trades. They could be struck by falling objects, vehicles or the delivery of modules, or interfere with the scaffold or the work. | Scaffold supplied by others. Barriers. | 3×4=12 | Set barriers and signs on the ground exclusion zone and keep a person as a banksman if deliveries or the exclusion zone are next to the pavement or road. Deliver and unload modules only with the ground zone controlled. Agree with the principal contractor and the scaffolder that no other trade works on the scaffold or underneath while the roof is being worked on, and keep the scaffold gates and ladder bay secured when no one is working. Check the zone is intact at each return and after any break. | Medium |
| Disturbing unidentified asbestos-containing materials when drilling into, fixing to or lifting existing roof, loft, wall or ceiling fabric (building age not confirmed) | Operatives, household members and neighbours, who could breathe in fibres. The health effects can be fatal and appear years later. | Competent installers. Asbestos management survey or register to be checked with the client. | 2×5=10 | Check the client's asbestos register or management survey for the roof, loft, cable route and inverter area before work starts, as required by Regulation 5 of the Control of Asbestos Regulations 2012. If the building is pre-2000 or its age is not confirmed and the register does not cover these areas, a refurbishment survey of those areas is needed first. This is a check to be made, not a finding that asbestos is present. Stop-work rule: if suspect material is found, stop, keep people away, do not touch or clean it up, and report it to the client and the principal contractor before work carries on. Brief all operatives on this at the start. | Medium |
| Respirable crystalline silica (RCS) dust from drilling or fixing into masonry, brick, block or concrete (inverter wall fixings and cable entries) and from cutting or drilling roof tiles | The operatives doing the work and anyone nearby, including the household and neighbours, breathing the dust. Long-term exposure can cause serious lung disease. | Competent installers. Work is limited to a small number of fixings and cable entries. | 3×4=12 | Plan the work to reduce drilling and cutting, for example using existing cable routes and clips where possible and not cutting tiles. Use on-tool extraction (M-class or H-class vacuum) or water suppression on every drill used on masonry, concrete or tile. Keep others away from the work area and clean up with an H-class or M-class vacuum, never dry sweeping or compressed air. Controlled under the Control of Substances Hazardous to Health Regulations (COSHH) 2002, following HSE Construction Information Sheet CIS36 Construction dust and the RCS workplace exposure limit of 0.1 mg/m3 (8-hour TWA) in HSE EH40/2005. Then RPE with an assigned protection factor of at least 20 (FFP3 disposable or equivalent), face-fit tested and worn clean shaven. | Medium |
| Cuts, abrasions and hand injuries from sharp aluminium rail edges, broken tiles, crimp tools and hand tools | Operatives. Lacerations to hands and forearms. | Competent installers. Tools in good condition. | 4×2=8 | Deburr or file cut ends of rails and cable trays before fitting. Keep tool blades, crimp tools and drills in good condition and check them before use under the Provision and Use of Work Equipment Regulations (PUWER) 1998. Use tool bags and keep sharp parts covered when not in use. Stack broken tiles safely and remove them from the roof. Cut-resistant gloves (EN 388) as backup. | Low |
| Working in the loft space for cable runs: falling through the ceiling, low light, heat, restricted movement and insulation fibres | Operatives. Falls through the ceiling, strains, heat stress and skin or breathing irritation. | Competent installers. Loft access by hatch. | 3×3=9 | Confirm the loft is boarded or lay a crawling board between the joists and never step on the ceiling. Use task lighting and keep the loft work to the minimum time. Move or fold back insulation carefully and put it back after. Keep the household out of the room below when work is overhead. Check for asbestos register information for the loft first. Disposable overalls, gloves and a dust mask or RPE as backup. | Low |
| Roof structure or fixing failure: roof anchors or rails fixed to rafters of unknown condition, increasing load on an existing roof | Operatives and the household if the structure or array is not sound. Water ingress and damage to the property. | Competent installers. Manufacturer's mounting instructions. | 2×4=8 | Inspect the rafters and roof covering from the loft and from the roof before fixing and confirm the roof is suitable for the array. If rafters are damaged, rotten or undersized, stop and get advice from a structural engineer or the manufacturer before going on. Fix anchors to rafters only, to the manufacturer's spacing and fixing instructions, and weather each penetration properly. Do not stack heavy loads on one part of the roof. | Low |
| Trips and snagging on cables, hoses, packaging and tools on the scaffold, roof and ground | Operatives, household members and anyone entering the work area. | Operatives trained. Housekeeping. | 4×2=8 | Tidy as you go: clip cabling as it is laid and keep walkways and scaffold boards clear. Have waste bags and a place for offcuts and packaging. Keep leads and extraction hoses off the scaffold gangway. Take everything away at the end of each day and do not leave cables across the household's paths. Safety footwear (EN ISO 20345) as backup. | Low |