Winter construction in the GTA: a builder's checklist

Updated October 2026 · By GTA Tarping INC, Newmarket

When to plan around freeze-up

Freeze-up in the GTA usually starts in November. Plan winter protection in early fall: confirm which homes will have masonry or envelope work in the cold months, and book tarping, heat and frost protection before demand peaks.

Enclosures and heaters: Ontario rules

• Tarp scaffolds on the elevations where work continues.
• O. Reg. 213/91 (Construction Projects), Section 49, sets rules for heaters used in enclosures and under tarpaulins. Keep clearance between heaters and tarps or materials, and ventilate the enclosure.
• Confirm who supplies, fuels and monitors heaters.
• Check enclosures after every wind event.

See winter scaffolding tarping.

Masonry in the cold

Ontario Building Code 9.20.14.1 requires mortar and masonry at 5 °C or warmer during installation and for at least 48 hours after, and no frozen materials. Keep materials covered and warm and protect new work. Read Cold-weather masonry in Ontario.

Envelope exposure over winter

House wrap and membranes have manufacturer limits on UV exposure and application temperature. If cladding is delayed over winter, plan the wrap schedule so it isn't exposed past the limit, and install self-adhered membranes only within the manufacturer's temperature range. See Tyvek and Blueskin building envelope.

Frost protection (straw, blankets)

Protect footings, slabs and backfill from frost with straw or insulated blankets as your engineer or supervisor directs. Don't place concrete or backfill on frozen ground.

Site safety

• Keep walkways, ladders and scaffold platforms clear of snow and ice.
• Keep enclosures ventilated where fuel-fired heaters are used.
• Brief crews on cold stress and PPE.
• Re-inspect scaffolds and enclosures after storms.

Download the checklist

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• [ ] Winter homes and elevations identified
• [ ] Tarping booked and measured before freeze-up
• [ ] Heater supply, fuel and monitoring confirmed
• [ ] Masonry materials covered and kept warm
• [ ] Envelope exposure and temperature limits checked
• [ ] Frost protection planned for footings, slabs and backfill
• [ ] Snow and ice plan for access and scaffold platforms
• [ ] Post-storm inspection routine in place

Get a quote · Related guide: What winter tarping costs in the GTA