Ontario winters hit construction sites hard. Between November and March, freezing rain, black ice, compacted snow, and sub-zero wind chills turn every walkway, scaffold platform, and access ramp into a potential injury zone. Slip-and-fall incidents spike dramatically during winter months, and on construction sites — where uneven terrain, open structures, and elevated work surfaces are the norm — the consequences can be severe.
According to the Workplace Safety and Insurance Board (WSIB), slips, trips, and falls consistently rank among the top causes of lost-time injuries in Ontario construction. Many of these injuries are preventable with proper planning, consistent housekeeping, and the right equipment. This guide covers the essential strategies every Ontario construction site should implement when temperatures drop.
De-Icing Protocols That Actually Work
Reactive de-icing — waiting until someone slips to throw down salt — is not a protocol. An effective winter de-icing program is proactive and systematic.
Pre-treat before freezing events — apply granular salt, calcium chloride, or sand to walkways, access ramps, scaffold platforms, and loading areas before freezing rain or overnight temperature drops. Pre-treatment prevents ice from bonding to surfaces and is far more effective than trying to break ice after it has formed.
Assign de-icing responsibility — designate specific workers or a rotating crew to handle de-icing duties at the start of each shift. If nobody owns the task, nobody does the task.
Stock materials on-site — keep bulk quantities of de-icing salt, calcium chloride pellets, and coarse sand at multiple locations around the site. Workers should not have to walk 200 metres across an icy site to retrieve a bag of salt.
Monitor temperature transitions — the most dangerous conditions often occur when temperatures hover around the freezing mark. Melt-freeze cycles create black ice that is nearly invisible. Increase de-icing frequency during these transitions.
Document applications — log when de-icing was performed, which areas were treated, and which materials were used. This documentation supports due diligence and can be critical in the event of an incident investigation.
Winter Housekeeping Standards
Good housekeeping matters year-round, but in winter it becomes a direct safety intervention. Snow accumulation hides tripping hazards, and ice makes every obstruction more dangerous.
Clear snow continuously — do not wait for the end of the day. Assign workers to clear walkways, stairs, ramps, and scaffold platforms throughout the shift. A few centimetres of compacted snow on a scaffold plank is an accident waiting to happen.
Keep drainage paths open — blocked drains lead to standing water, which freezes overnight. Ensure drainage channels, floor drains, and runoff paths are clear of debris and snow.
Remove snow from materials and equipment — snow on stored lumber, steel, or equipment creates slip hazards when workers handle those materials. Brush off materials before moving them.
Mark hidden hazards — snow can obscure floor openings, changes in elevation, protruding rebar, and other hazards. Use high-visibility markers, flags, or barriers to indicate known hazards that may be buried under snow.
Heated Shelter Requirements
Ontario Regulation 213/91 (Construction Projects) does not set a general heated-shelter rule for outdoor work, but the OHSA requires employers to take every precaution reasonable in the circumstances to protect workers, and in cold weather that means a heated shelter workers can reach.
The shelter should be located within reasonable proximity to the work area. Workers need access to warm, dry space to prevent hypothermia, frostbite, and cold stress, and to dry wet clothing that can accelerate heat loss.
Beyond regulatory compliance, heated shelters improve safety indirectly. Cold, fatigued workers have slower reaction times, reduced grip strength, and impaired judgment — all factors that increase slip-and-fall risk. Regular warm-up breaks help workers maintain alertness and physical coordination throughout the shift.
Ice Cleats and Winter Footwear
Standard CSA-approved safety boots are not designed for ice. The rubber soles that perform well on dry concrete or gravel lose traction on frozen surfaces. Winter-specific traction devices are essential.
Strap-on ice cleats — tungsten carbide or hardened steel spikes that attach over safety boots. These provide excellent traction on ice and packed snow. Look for models rated for industrial use, not consumer-grade walking cleats.
Winter safety boots with built-in traction — some manufacturers produce CSA-approved boots with integrated ice-grip soles (such as Green Diamond or Arctic Grip technology). These eliminate the need for separate cleats.
Insulated boots — cold feet lead to reduced sensation and poor balance. Insulated, waterproof safety boots rated to at least -30 degrees Celsius help maintain circulation and grip control.
Replacement schedule — ice cleats wear down. Inspect them weekly during winter and replace any cleats with worn or missing spikes. A cleat with three missing studs is worse than no cleat at all because it creates a false sense of security.
Covered Walkways and Access Routes
Where feasible, construct covered walkways or temporary canopies over primary access routes, stairways, and high-traffic areas. Covered walkways prevent snow and ice accumulation on walking surfaces and reduce the de-icing burden significantly.
Plywood sheeting, corrugated metal, or heavy-duty tarps stretched over framed structures can provide effective overhead protection. The investment in materials and labour pays for itself quickly when you consider the cost of a single lost-time injury — not to mention the project delays that follow a serious incident.
For scaffold access, consider enclosed scaffold stairways with roofing panels. These keep stair treads dry and ice-free, which is critical since scaffold stairways are where many winter falls occur.
Snow Load Monitoring
Snow accumulation on temporary structures — scaffolding, formwork, temporary roofs, and material storage areas — creates load hazards that can lead to structural collapse. This is a distinct risk from slip-and-fall, but it is equally important during winter operations.
Know the design loads — every temporary structure has a rated load capacity. Fresh snow weighs approximately 1.0 to 1.5 kN per cubic metre, but wet or compacted snow can exceed 3.0 kN per cubic metre. Ice is even heavier.
Monitor accumulation daily — assign someone to measure snow depth on scaffold platforms, temporary roofs, and formwork after each snowfall.
Remove snow before it becomes dangerous — do not wait for the structure to show signs of distress. Clear snow from temporary structures regularly, and do so safely — workers removing snow at height need fall protection.
Watch for drifting — wind can cause uneven snow accumulation, concentrating loads on one side of a structure. Drifted snow against a scaffold or temporary wall can impose lateral loads the structure was not designed to handle.
Slip Hazard Assessment
A formal slip hazard assessment should be conducted at the start of winter and updated as conditions change. This assessment identifies high-risk areas, assigns control measures, and establishes monitoring responsibilities.
Map high-risk zones — entrances, ramps, scaffold access points, loading areas, and any surface exposed to precipitation or runoff. These areas get priority treatment.
Evaluate lighting — winter means shorter days and longer periods of darkness. Ice and snow hazards that are visible in daylight become invisible at dawn and dusk. Increase lighting intensity in high-traffic areas during winter months.
Review at each toolbox talk — make winter slip hazards a standing agenda item at daily toolbox talks. Conditions change rapidly — what was safe at 7 AM may be a sheet of ice by 10 AM after a temperature drop.
Incident Statistics and the Case for Prevention
Musculoskeletal injuries from slips and falls increase during winter months across Ontario workplaces, with construction among the hardest-hit sectors. Fractured wrists, broken ankles, hip injuries, and head trauma from falls on ice are common — and many result in weeks or months of lost time.
A lost-time slip-and-fall injury in Ontario construction is expensive when you factor in WSIB claims, replacement labour, investigation time, and project delays. A comprehensive winter safety program — ice cleats, de-icing materials, heated shelters, and covered walkways — costs a fraction of that per worker per season.
Prevention is not just cheaper. It is the legal obligation of every constructor and employer under the Occupational Health and Safety Act. Take winter seriously, prepare early, and keep your crews on their feet.
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