Can concrete work be done in winter?

Concrete work can be done in winter in Ottawa, but it requires special precautions and techniques that significantly increase costs and complexity. Most contractors avoid pouring concrete when temperatures drop below -10°C, and the work becomes increasingly challenging as temperatures fall.

Cold Weather Concrete Challenges

When concrete freezes before it reaches sufficient strength (typically within the first 24-48 hours), the water in the mix expands and can permanently damage the concrete's structure. In Ottawa's harsh winter climate, this means concrete work requires heated enclosures, special cold-weather concrete mixes with accelerators, and extended curing protection. The concrete must be kept above 10°C during the initial curing period, which can last several days depending on the mix and thickness.

What's Possible vs. What's Practical

Small interior concrete work like basement floors or utility pads can often proceed in winter with proper heating of the space. However, exterior work like driveways, sidewalks, foundations, or patios becomes much more complex. Contractors need to use insulated blankets, heated enclosures, or even temporary heated structures. The concrete itself requires special winter mixes with accelerators and potentially heated aggregates, which can increase material costs by 20-40%.

Ottawa Permit Considerations

The City of Ottawa doesn't prohibit winter concrete work, but inspectors may require additional documentation about cold-weather procedures. For foundation work, you'll need to demonstrate proper frost protection measures. Building permits remain valid through winter, but scheduling inspections can be more challenging due to weather delays.

Cost and Timeline Impact

Winter concrete work typically costs 25-50% more than summer work due to special materials, heating requirements, and weather delays. A simple driveway that might cost $8-12 per square foot in summer could run $12-18 per square foot in winter. Timeline uncertainty increases significantly - a project planned for 3 days might stretch to a week due to weather windows.

Professional Recommendation

Unless it's an emergency repair or critical timeline issue, most experienced Ottawa contractors recommend waiting until spring for major concrete work. The frost line in Ottawa extends 4 feet deep, so any excavation work becomes much more difficult once the ground freezes. For urgent repairs, consult with contractors experienced in cold-weather concrete techniques.

Next Steps

If you must proceed with winter concrete work, get quotes from multiple contractors experienced with cold-weather pours, ensure your permit allows for seasonal construction methods, and build extra time and budget into your project timeline.