Preventing Ice Dams and Winter Home Hazards:

Insights from George Mendes, C.M.I.

 

Winter presents unique challenges for homeowners, with ice dam formation being a prevalent 

and preventable issue. As a Certified Master Inspector (C.M.I.) and owner of Home Suite Home 

Inspections, I’ve observed that many of these problems are self-inflicted and can be avoided 

with proper maintenance and awareness.

What Causes Ice Dams?

Ice dams occur when heat escapes from the living space into the attic, warming the roof and 

causing snow to melt. This water then refreezes at the eaves, creating a buildup of ice that 

traps additional melting snow, leading to potential water intrusion under shingles and into the 

home.

Key contributors include:

• Inadequate attic insulation: Allows heat to escape, warming the roof unevenly.

• Improper ventilation: Prevents cold air from maintaining a consistent attic 

temperature.

• Clogged gutters: Debris-filled gutters impede proper drainage, leading to ice buildup.

• Unsealed air leaks: Gaps around vents, chimneys, and attic access points permit 

warm air to enter the attic.

Preventing Ice Dams and Winter Roof Damage

To mitigate these issues, consider the following steps:

1. Assess Attic Insulation and Ventilation

While adding insulation is beneficial, neglecting proper ventilation can trap warm air, heating 

the roof from within. I’ve encountered situations where homeowners install bathroom vent fans 

but fail to insulate or extend the ductwork to a dedicated roof vent, leading to moisture 

problems and mold growth in the attic. Ensure any modifications are correctly executed, and 

consider a professional inspection for verification.

2. Maintain Clean Gutters and Downspouts

Regularly clear gutters of leaves and debris to prevent water pooling and freezing. Extending 

downspouts away from the foundation aids in directing melting snow and rain away from the 

roofline.

3. Monitor Furnace and Water Heater Vents

Heavy snowfall can obstruct furnace and hot water tank vents, posing a silent but deadly 

carbon monoxide hazard. A simple check after each snowfall can prevent this serious health 

risk.

4. Utilize Roof Rakes for Snow Management

Excessive snow accumulation, especially near the eaves, can be managed with a roof rake to 

reduce ice dam formation. Exercise caution to avoid damaging shingles.

5. Seal Attic Bypasses and Air Leaks

Prevent warm air from escaping into the attic by sealing gaps around chimneys, plumbing vents, 

and attic hatches, maintaining a consistent attic temperature.

6. Install Roof De-Icing Cables

Roof de-icing cables, also known as heat cables, can be an effective solution to prevent ice 

dams. These cables are installed along the roof’s edge, gutters, and downspouts to create a 

clear path for melting snow and ice to drain away from your home. When installing de-icing 

cables, it’s essential to:  

• Use a Ground Fault Circuit Interrupter (GFCI) Outlet: Plug the de-icing cables into a 

GFCI-protected outlet to prevent electrical hazards. If a GFCI outlet is not available near the 

installation area, consider hiring a licensed electrician to install one.  

• Follow Proper Installation Guidelines: Install the cables in a zigzag pattern along the 

roof edge, ensuring they extend into the gutters and downspouts. This setup facilitates 

effective melting and drainage of snow and ice. Always adhere to the manufacturer’s 

installation instructions and safety precautions.  

• Regularly Inspect and Maintain the System: Before the winter season, inspect the 

cables for any signs of wear or damage. Ensure all connections are secure and the system is 

functioning correctly.

Final Thoughts

At Home Suite Home Inspections, we’ve witnessed the damage that ice dams and inadequate 

winter maintenance can cause. Proactive measures are essential. If you’re uncertain about your 

attic’s insulation, ventilation, or roof drainage systems, have them inspected before winter 

intensifies. Regularly checking that furnace and water heater vents are free from snow and ice 

is crucial for your family’s safety.

A small investment in regular maintenance can prevent significant repairs and ensure your 

home remains safe and warm throughout the winter months.

About the Author

George Mendes, C.M.I., is a Certified Master Inspector and the owner of Home Suite Home 

Inspections. Serving the Hamilton-Niagara Region since 2006, the company has expanded to 

Mississauga, Brampton, Milton, and Oakville. Home Suite Home Inspections has been honored 

with the Consumer Choice Award for eight consecutive years, reflecting their commitment to 

excellence in home inspection services.

Consumer Choice Awardhttps://www.ccaward.comHome Suite Home Inspections

For more information or to schedule an inspection, visit www.homesweethomeinspections.ca 

(https://www.homesweethomeinspections.ca) or call 905-324-HSHI (4744).