Can you test air conditioning in winter?

No. Operating an air conditioner when the outdoor temperature is below about 15°C (60°F) may damage the compressor. Inspectors perform a visual assessment only.

How is the roof inspected when it is covered in snow?

When roof access is unsafe, inspectors assess the roof from the ground using visual observation (often with binoculars) and check the attic for signs such as water stains, excess humidity (frost on nails), and structural indicators.

Is a home inspection more expensive in the winter?

No. Pricing remains consistent year-round. Winter may offer better scheduling availability compared to busier seasons.

The #1 Reason Montreal Roofs Leak in Winter: Ice Damming

You’re sitting on your sofa, enjoying a quiet winter evening, when you suddenly hear it: drip… drip… drip.

You investigate and find water staining your ceiling or pooling on the carpet. Your first thought is that there must be a hole in the roof — but in a Montreal winter, the culprit is usually ice damming.

At Mose Home Inspection, we see the damaging effects of ice dams every year, especially in duplexes, triplexes, condos, and older homes across Greater Montreal. Understanding why they form is the first step toward protecting your property from costly water damage.

What Is an Ice Dam?

An ice dam is a ridge of ice that forms along the edge of your roof (the eaves).
While it may look decorative, it acts like a wall that traps melting snow behind it. With nowhere to drain, water backs up under shingles and seeps into ceilings, walls, and insulation.

Over time, this can lead to:

Water stains
Mold growth
Structural damage
Insulation failure
Insurance claims

The Anatomy of a Leak: How Ice Dams Form

Ice damming is caused by temperature imbalance on your roof and usually follows this process:
1. The Warm Attic
Heat escapes from your living space into the attic, warming the roof surface.
2. The Runoff
Snow melts in warmer roof areas and flows downward.
3. The Freeze
At the colder roof edge, water refreezes and forms a solid ice barrier. Over time, this barrier grows and traps more water behind it.

The Main Culprit: Why Your Attic Is Too Warm

If your home has ice dams, it almost always has a warm attic problem.
This is typically caused by:
Insufficient Insulation
Not enough insulation allows heat to rise into the attic.
Air Leaks (Bypasses)
Warm air escapes through:

Pot lights
Attic hatches
Plumbing stacks

Electrical openings
Poor Ventilation
Blocked soffit or roof vents prevent cold air from flushing warm air out.

When insulation, air sealing, and ventilation are out of balance, ice dams form.

Quick Ice Dam Risk Checklist

Your home may be at risk if you notice:

✔️ Thick icicles along eaves 
✔️ Uneven snow melting 
✔️ Drafty upper floors 
✔️ High winter heating bills 
✔️ Repeated ceiling stains

If two or more apply, a professional inspection is recommended.

Low-Slope Roofs and Older Montreal Homes

Homes with low-slope roofs are more vulnerable because water moves slowly, giving it more time to freeze.

Many older Montreal properties also have limited insulation space near the eaves, creating a permanent cold/warm boundary — the perfect condition for ice dams.

Why Ice Dams Matter During a Sale

Ice dam damage discovered during an inspection can:

Delay closings
Trigger renegotiations
Affect insurance eligibility
Reduce buyer confidence

Identifying attic heat loss early protects your transaction and your investment.

How Mose Inspectors Evaluate Ice Dam Risk

During an inspection, our team evaluates:

Attic insulation depth and coverage
Air leakage points
Ventilation pathways
Roof-edge conditions
Signs of past moisture intrusion

This allows us to assess current risk and recommend corrective actions when needed.

How to Handle an Active Ice Dam (Safely)

If you notice winter leaks:
❌ Don’t Attempt Dangerous DIY
Climbing ladders or chipping ice can cause serious injury and roof damage.
✅ Call a Professional
Steam-based removal is the safest method.
✅ Reduce Short-Term Risk
Using a roof rake from the ground to remove excess snow near roof edges may help temporarily.
✅ Address Interior Damage Quickly
Dry affected areas promptly to prevent mold.

The Permanent Fix: Summer Preparation

The best time to prevent ice dams is in warm weather.
Improve Insulation
Ensure even, adequate attic coverage.
Seal Air Leaks
Use foam and caulking around penetrations.
Upgrade Roofing Protection
Install ice and water shield membranes 6–8 feet from eaves during roof replacement.
Maintain Ventilation
Keep soffit and roof vents clear.

Protect Your Home Before Winter Problems Start

Ice dams are not caused by weather — they are caused by attic conditions.
A professional inspection helps identify risks before they become expensive repairs.

Book your home inspection today

and prevent costly winter water damage.