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Ice Dam Risk Map · Winter 2026 · St. Catharines

St. Catharines Ice Dam Risk Map — Where Roofs Freeze First

TL;DR

In St. Catharines, ice dams form when attic heat melts snow that refreezes at the cold eave. High-risk zones share three traits: 1½-story rooflines, under-insulated attics (R-30 or lower), and undersized eavestroughs. Fixes: seal attic bypasses, add R-60 insulation, install heat cable at problem eaves, and upsize downspouts to 3"×4". Same-week diagnostic + estimate available across St. Catharines.

Call (437) 475-3344

Why ice dams are a St. Catharines problem

St. Catharines sits in a freeze-thaw corridor — daytime highs above 0°C and overnight lows well below. That cycle is the exact condition ice dams need. A warm attic melts the snow layer against the roof deck; the meltwater runs to the unheated eave; it refreezes into a dam; the next melt pushes water uphill under the shingles. Damage shows up as ceiling stains, peeling paint at the top of exterior walls, and rot at the fascia.

Homes built before the 1990 Ontario Building Code update are the most at risk — those attics were insulated to roughly R-20 and rarely had continuous soffit-to-ridge venting. Newer builds fail when pot lights, bath fans, or attic hatches leak warm air into the attic.

The four-step permanent fix

  1. Seal. Air-seal every attic bypass — pot lights, top plates, plumbing stacks, bath fan boots.
  2. Insulate. Blow cellulose to R-60 (about 16 inches) across the entire attic floor.
  3. Vent. Continuous soffit intake plus ridge exhaust — 1 sq ft NFA per 300 sq ft of attic floor.
  4. Drain. 5" or 6" K-style eavestrough, 3"×4" downspouts, and heat cable on chronic-dam eaves.

St. Catharines pricing snapshot

  • Ice-dam steam removal (emergency): $450–$950 per visit
  • Heat cable install (40 ft eave + downspout): $600–$1,100
  • Attic air-sealing + top-up to R-60: $2,800–$4,200
  • Full gutter replacement (2-storey detached): $2,400–$4,800

Neighborhood-by-neighborhood in St. Catharines

Ice dam risk isn't uniform across St. Catharines. Older housing stock, tree cover, and lot exposure to prevailing northwest winds all shift the risk profile. Below: risk read-outs for the neighborhoods we service most.

St. Catharines

Downtown St. Catharines

  • Risk band: Elevated — driven by 1½-storey builds and long eaves.
  • Typical fix in Downtown St. Catharines: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Downtown St. Catharines through March.
  • Free 30-minute attic + roof assessment for Downtown St. Catharines homeowners this winter.
St. Catharines

Port Dalhousie

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Port Dalhousie: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Port Dalhousie through March.
  • Free 30-minute attic + roof assessment for Port Dalhousie homeowners this winter.
St. Catharines

Grantham

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Grantham: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Grantham through March.
  • Free 30-minute attic + roof assessment for Grantham homeowners this winter.
St. Catharines

Facer

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Facer: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Facer through March.
  • Free 30-minute attic + roof assessment for Facer homeowners this winter.
St. Catharines

Fairview

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Fairview: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Fairview through March.
  • Free 30-minute attic + roof assessment for Fairview homeowners this winter.
St. Catharines

Merritton

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Merritton: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Merritton through March.
  • Free 30-minute attic + roof assessment for Merritton homeowners this winter.
St. Catharines

Western Hill

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Western Hill: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Western Hill through March.
  • Free 30-minute attic + roof assessment for Western Hill homeowners this winter.
St. Catharines

Louth

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Louth: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Louth through March.
  • Free 30-minute attic + roof assessment for Louth homeowners this winter.
St. Catharines

Vansickle

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Vansickle: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Vansickle through March.
  • Free 30-minute attic + roof assessment for Vansickle homeowners this winter.
St. Catharines

Martindale

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Martindale: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Martindale through March.
  • Free 30-minute attic + roof assessment for Martindale homeowners this winter.
St. Catharines

Grapeview

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Grapeview: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Grapeview through March.
  • Free 30-minute attic + roof assessment for Grapeview homeowners this winter.
St. Catharines

Glendale

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Glendale: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Glendale through March.
  • Free 30-minute attic + roof assessment for Glendale homeowners this winter.
St. Catharines

Glenridge

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Glenridge: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Glenridge through March.
  • Free 30-minute attic + roof assessment for Glenridge homeowners this winter.
St. Catharines

Queenston

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Queenston: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Queenston through March.
  • Free 30-minute attic + roof assessment for Queenston homeowners this winter.
St. Catharines

Secord Woods

  • Risk band: Elevated — driven by 1½-storey builds and long eaves.
  • Typical fix in Secord Woods: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Secord Woods through March.
  • Free 30-minute attic + roof assessment for Secord Woods homeowners this winter.
St. Catharines

Lakeport

  • Risk band: Elevated — driven by 1½-storey builds and long eaves.
  • Typical fix in Lakeport: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Lakeport through March.
  • Free 30-minute attic + roof assessment for Lakeport homeowners this winter.
St. Catharines

Lakeshore

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Lakeshore: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Lakeshore through March.
  • Free 30-minute attic + roof assessment for Lakeshore homeowners this winter.
St. Catharines

Bunting

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Bunting: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Bunting through March.
  • Free 30-minute attic + roof assessment for Bunting homeowners this winter.
St. Catharines

Ridley

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Ridley: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Ridley through March.
  • Free 30-minute attic + roof assessment for Ridley homeowners this winter.
St. Catharines

Old Glenridge

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Old Glenridge: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Old Glenridge through March.
  • Free 30-minute attic + roof assessment for Old Glenridge homeowners this winter.
St. Catharines

Burleigh Hill

  • Risk band: High — driven by 1½-storey builds and long eaves.
  • Typical fix in Burleigh Hill: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Burleigh Hill through March.
  • Free 30-minute attic + roof assessment for Burleigh Hill homeowners this winter.
St. Catharines

Power Glen

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Power Glen: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Power Glen through March.
  • Free 30-minute attic + roof assessment for Power Glen homeowners this winter.
St. Catharines

Silvan

  • Risk band: Elevated — driven by 1½-storey builds and long eaves.
  • Typical fix in Silvan: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Silvan through March.
  • Free 30-minute attic + roof assessment for Silvan homeowners this winter.
St. Catharines

Rykert

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Rykert: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Rykert through March.
  • Free 30-minute attic + roof assessment for Rykert homeowners this winter.
St. Catharines

Applewood

  • Risk band: Elevated — driven by 1½-storey builds and long eaves.
  • Typical fix in Applewood: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Applewood through March.
  • Free 30-minute attic + roof assessment for Applewood homeowners this winter.
St. Catharines

Haig

  • Risk band: Moderate — driven by 1½-storey builds and long eaves.
  • Typical fix in Haig: attic air-sealing + R-60 top-up, plus heat cable on the north-facing eave.
  • Emergency steam removal available same-day across Haig through March.
  • Free 30-minute attic + roof assessment for Haig homeowners this winter.

FAQ — Ice Dam Risk in St. Catharines

Are ice dams covered by insurance in St. Catharines?+

Most Ontario policies cover the interior water damage from an ice dam but not the ice dam itself, and repeated claims can trigger non-renewal. Fixing the root cause (insulation + venting) is usually cheaper than one deductible.

Will heat cable alone stop ice dams?+

No. Heat cable is a symptom manager. Without attic air-sealing and proper insulation, dams will still form above the cable. Use it as a supplement, not a fix.

How fast can you respond to an active ice dam?+

Same-day emergency steam removal across St. Catharines. Do not chip ice with hammers or use rock salt on the roof — both void most shingle warranties.

What R-value should my attic be?+

Ontario's current target is R-60. Anything under R-40 is a strong ice-dam predictor.

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