🧊 The Real Problem: Ice Dams

 When homeowners in South Jersey notice a roof leak, it often happens during the winter—not during heavy rain, but when snow is sitting on the roof. This can feel confusing, but the cause is usually very specific and preventable.

Let’s break down exactly why this happens.

🧊 The Real Problem: Ice Dams

The most common reason roofs leak during snow is something called an ice dam.

🔍 What is an ice dam?

An ice dam forms when:

1. Snow builds up on your roof

2. Heat from your attic melts the snow

3. Melted water flows down toward the edges

4. The colder edges refreeze

5. Ice builds up and traps water behind it

That trapped water has nowhere to go—so it starts pushing back under your shingles.

💧 Why It Leaks During Snow (But Not Rain)

🌧️ During Rain:

• Water flows quickly off the roof

• Shingles are designed to shed water downward

• No blockage = no problem

❄️ During Snow:

• Snow melts slowly

• Ice blocks proper drainage

• Water sits on the roof longer

• Water gets forced under shingles, flashing, and into your home

👉 Roofing systems are designed for shedding water—not holding it.

🏠 Common Leak Areas During Snow

Leaks usually show up in these areas:

• Roof valleys (where two slopes meet)

• Around chimneys and flashing

• Near roof vents and skylights

• Along the edges/eaves of the roof

These are the most vulnerable spots where water can back up.

🌡️ The Hidden Cause: Poor Attic Insulation & Ventilation

This is where most homeowners don’t realize the real issue.

🔥 What’s happening:

• Warm air escapes into the attic

• It heats the roof from underneath

• Snow melts unevenly

• Refreezing happens at the edges

👉 This temperature difference is what creates ice dams.

⚠️ Signs You Have an Ice Dam Problem

• Icicles hanging from gutters

• Water stains on ceilings or walls

• Dripping during cold weather (not rain)

• Snow melting unevenly on your roof

If you see these signs, your roof is at risk.

🛠️ How to Prevent Roof Leaks in Winter

✅ 1. Improve Attic Insulation

Keeps heat inside your home—not escaping to the roof.

✅ 2. Proper Roof Ventilation

Allows cold air to circulate and keeps roof temperature even.

✅ 3. Install Ice & Water Shield

A waterproof barrier under shingles that protects against backup.

✅ 4. Keep Gutters Clean

Prevents ice buildup at the edges.

✅ 5. Remove Excess Snow

Safely removing snow reduces the chance of ice dams forming.