Planning for winter work
The September schedule update puts the level 1 slab pour in mid-December and exterior framing into January. The estimate carries a single round number for winter conditions. The project manager asks the superintendent what that number is supposed to buy.
Winter adds cost and time an estimate rarely shows: enclosures, fuel, heater tending, snow clearing, short days, slower crews, and materials that cannot go in below their minimum temperature. It is also regulated work, and the rules differ: the Canadian Centre for Occupational Health and Safety notes that some Canadian jurisdictions set acceptable temperature ranges while others use published cold-stress limits.
- List the temperature-sensitive work, such as concrete, masonry, roofing, sealants and coatings, with minimum conditions from the specification and product data.
- Decide enclosure and heat for each activity: who supplies and tends it, at what cost, and what the Division 01 sections on temporary utilities and enclosures say. In British Columbia, bracing for a scaffold enclosed by tarps or another cover must follow a professional engineer's instructions.
- Treat heaters as a hazard: fuel-fired heaters give off carbon monoxide. Ontario's construction health and safety association advises indirect-fired heaters for enclosed spaces and testing heated areas for carbon monoxide, and says only workers holding a record of training may operate propane, gas or oil heaters there. US federal rules add requirements for fresh air and for clearance from combustible tarps.
- Agree cold-weather concreting before the first cold pour: the specification, the concrete standard it cites and the engineer set protection, temperatures, curing and stripping times. US ready-mix industry guidance says fresh concrete should be protected from freezing, with protection ready before placement and fuel-fired heaters in enclosed spaces vented, for safety and to protect the fresh surface. Add these to the pre-pour check.
- Plan crew welfare to your jurisdiction's cold-stress rules. Where workers may be exposed to cold stress, British Columbia requires a cold stress assessment, a cold exposure control plan and, below an equivalent chill temperature of −7 °C, a nearby heated shelter; the national centre also advises scheduling heavy work in the warmer part of the day and a buddy system.
- Plan snow and ice: who clears it, where it goes (never on laydown, fire routes or drains), sanding, and lighting for short days.
- Keep winter items separate in the estimate and schedule, check them against the forecast each week, and record the days weather stops work.
Checklist
Before the first cold week
- Sensitive work listed with its minimum conditions
- Enclosures and heat assigned, priced and ordered
- Heater type, ventilation and carbon monoxide testing planned
- Cold-weather concreting agreed with the engineer
- Cold-stress plan and warm shelter ready
- Snow clearing and storage assigned
Check your understanding
Why is "winter conditions: $40,000" a weak line in an estimate?
Show the answer
Because nobody can check it against what the winter will need. Split into items tied to activities and periods, it shows what the money buys, can be tracked, and can be compared with moving the work out of the cold.
Sources
- Cold Environments – Control Measures
- OHS Regulation Part 7: Noise, Vibration, Radiation and Temperature (sections 7.33 to 7.36, Cold exposure)
- OHS Regulation Part 13: Ladders, Scaffolds and Temporary Work Platforms (section 13.11)
- Heaters (safety talk)
- 29 CFR 1926.154 Temporary heating devices
- CIP 27 – Cold Weather Concreting
- NMS table of contents (Division 01: 01 51 00 Temporary Utilities; 01 56 00 Temporary Barriers and Enclosures)
