Frozen pipe prevention checklist for Canadian cold snaps

Practical steps to reduce frozen-pipe risk before prolonged cold, especially around exterior walls and vulnerable service lines.

Updated September 28, 2026

Know which pipes are vulnerable

Toronto identifies plumbing near exterior walls and where the water service enters the foundation as common freeze locations. Ottawa notes that prolonged severe cold can freeze underground water-service pipes at vulnerable properties.

Prepare before the coldest night

Know the location of the main water shutoff, keep vulnerable indoor areas warm, and follow any municipality-specific instructions if your property receives a run-water advisory or similar notice. Do not invent a constant-drip strategy when local authorities have provided different instructions for your service line.

Create a response plan

If water stops, determine whether the problem affects one fixture or the whole property. If a pipe is cracked, bulging or leaking, shutoff readiness matters because damage can appear as the pipe thaws. Toronto specifically warns against using an open flame to thaw pipes.

Primary sources

City of Toronto — Prevent or Thaw Frozen PipesCity of Ottawa — Frozen water service pipes