How Snow and Ice Can Damage Your NEPA Roof (and How to Spot It)

Scranton, Pennsylvania, averages around 41” of snowfall annually, putting it over 10” above the national average. 

Much of that snow will stick to your roof all winter long, placing heavy pressure on your roof and eroding asphalt shingles, which can lead to structural damage. 

However, the real danger of snowfall comes from ice dams, which form on the perimeter of your roof as snow melts and freezes. Most modern roofs are now built with ice and water barriers, but if your roof is old or outdated, it may not have proper protection. 

Ice can also freeze standing water in gutters, forcing melting snow to accumulate around your foundation. 

This guide will discuss several winter threats to roofs in Northeast Pennsylvania and ways to winterize your roof for Pennsylvania’s frigid winters. 

How Winter Weather Puts Roofs at Risk

Your roof is built to withstand a lot in order to protect your home, but older or poorly installed roofs may suffer from eroded shingles, ice dams, or leaks that put your home and attic at risk. During the winter, a combination of moisture, freezing temperatures, and the weight of snow and ice can push roofing materials and structures past their limits.

Here are a few of the key culprits to watch out for this winter:

• Snow accumulation: Even light, fluffy snow adds up in weight. Wet, heavy snow can weigh up to 20 pounds per cubic foot, creating thousands of pounds of stress on your roof.
  
• Ice formation: When snow melts and refreezes, it forms thick layers of ice that trap moisture and block proper drainage.
  
• Freeze-thaw cycles: Repeated melting and freezing cause roofing materials to expand and contract, weakening seals and loosening shingles.

Together, these forces can cause a chain reaction of roof damage that starts small but worsens rapidly with every storm.

Top 6 Winter Threats to Roofs in Pennsylvania

1. Ice Dams

Ice dams form when warm air from your attic melts the underside of the snow on your roof. As meltwater runs down to the roof edge, where it’s colder, it refreezes, creating a ridge of ice.

Once that ice dam forms, new meltwater can’t drain off properly, causing the water to pool behind the dam and seep under shingles and flashing, leaking into your attic or walls.

Many homeowners are largely unaware of ice dams and may ignore obvious signs, such as icicles hanging from the edges of their roof. 

Signs of Ice Dam Damage

• • Water stains or bubbling paint on ceilings and walls
    
  • Icicles hanging from eaves or gutters
    
  • Mold growth in the attic or insulation
    
  • Damp or compressed attic insulation
    

How to Prevent Ice Dams

• • Improve attic insulation and ventilation: Proper airflow keeps your roof’s surface cold and prevents uneven melting.
    
  • Seal attic leaks: Warm air escaping from vents, chimneys, or light fixtures contributes to snow melt.
    
  • Use a roof rake: Gently remove snow buildup near the edges after major storms (without climbing onto the roof).
    
  • Consider heat cables: Electric de-icing cables can help melt ice along the eaves in problem areas.
    

2. Structural Stress from Heavy Snow

A little snow looks harmless, but when accumulation builds up, your roof can experience extreme weight loads. This is especially risky for older homes, flat or low-pitched roofs, or structures with aging support beams or damaged sheathing. 

Wet snow can be particularly heavy. For example:

• 10 inches of fresh snow = roughly 5 pounds per square foot
  
• 10 inches of wet snow = up to 20 pounds per square foot
  

If several storms pile on before melting, that weight can cause sagging, cracking, or even collapse.

Signs of Snow Load Damage

• • Sagging rooflines or ceilings
    
  • Cracking or popping sounds in the attic
    
  • Doors and windows that suddenly stick or misalign
    
  • Leaks around roof penetrations (vents, chimneys, skylights)
    

How to Relieve Accumulated Snow Pressure

• • Use a roof rake from the ground to remove excess snow.
    
  • Hire a professional for deep or compacted snow removal—never climb onto a snow-covered roof.
    
  • If you notice sagging or cracking, call a roofing or structural expert immediately.
    

3. Shingle and Flashing Damage

The constant freezing and thawing of winter can be brutal on asphalt shingles and metal flashing. As water seeps into small cracks or under lifted shingles, it freezes, expands, and causes further separation. Over time, this leads to broken seals, curling shingles, and corrosion.

Signs of Shingle or Flashing Damage

• • Missing, cracked, or curled shingles
    
  • Exposed nail heads or flashing that’s lifting
    
  • Dark streaks or granule loss on shingles
    
  • Water stains around chimneys, skylights, or vents
    

Maintenance Tips for Shingles and Flashing

• • Inspect your roof before and after winter storms.
    
  • Keep gutters and downspouts clear so meltwater can drain properly.
    
  • Replace damaged shingles or flashing promptly to prevent leaks.
    

4. Gutter and Downspout Issues

Gutters play a vital role in directing meltwater away from your roof and foundation, but when they’re clogged or frozen, it can allow water to accumulate around your foundation.

Additionally, ice accumulation in gutters can cause them to pull away from the roofline, damage fascia boards, and create dangerous icicles. When meltwater has nowhere to go, it can also back up under shingles and into your home.

Signs of Gutter Trouble

• • Ice hanging off the roof edges
    
  • Water dripping down siding even when it’s not raining
    
  • Detached or sagging gutters
    
  • Pooling water around the foundation
    

How to Maintain Gutters During Winter

• • Clean gutters thoroughly before winter.
    
  • Make sure downspouts extend several feet away from your home.
    
  • Add gutter guards or heating cables if ice buildup is a recurring issue.

5. Hidden Water Intrusion and Mold Growth

Not all winter roof damage is visible right away. Water that seeps through the roof deck or insulation can take weeks—or even months—to show up as visible staining or mold.

Over time, trapped moisture weakens your attic structure, reduces insulation performance, and fosters unhealthy air conditions.

How to Spot Hidden Moisture Damage

• • A musty odor in the attic or upper floors
    
  • Peeling paint or bubbling drywall
    
  • Damp insulation or visible mold patches
    
  • A sudden increase in heating bills (a sign that insulation has been compromised)
    

If you suspect moisture damage, it’s best to have a professional roof or insulation inspection. Thermal imaging can also help identify hidden wet spots before they spread.

6. Freeze-Thaw Damage on Flat Roofs

Homes and commercial buildings with flat or low-slope roofs face unique winter challenges, as meltwater tends to pool instead of draining, allowing it to refreeze overnight and damage membrane seams.

How to Identify Flat Roof Damage

• • Ponding water that lasts more than 48 hours after melting
    
  • Cracked seams or bubbles in the roofing membrane
    
  • Leaks appearing around vents or rooftop equipment
    

Keeping drains and scuppers clear is key. Professional maintenance before and after the season can save thousands in repair costs.

How to Inspect Your Roof After Winter

The best way to prevent winter roof damage is to conduct an inspection before and after the winter season. 

Perform a visual inspection in the fall, winter, and spring to spot potential issues as they manifest on your roof, looking for:

• Uneven snow melt (which can indicate poor insulation or ventilation)
  
• Missing shingles, sagging areas, or exposed wood
  
• Gutters containing icicles, ice dams, or debris buildup
  
• (Attic) Damp insulation, mold, or daylight that can be spotted through the roof boards
  

If you spot any warning signs, schedule a professional roof inspection. A home inspector can safely assess hidden damage and recommend targeted repairs before leaks and rot take hold.

Protecting Your Roof Year-Round

Winter roof damage is often preventable with the right preparation and maintenance. Here’s how to stay ahead this winter:

1. Schedule a pre-winter roof inspection: A professional can identify weak spots before the first snow falls.
   
2. Add insulation and ventilation: A balanced attic temperature prevents ice dams and reduces energy costs.
   
3. Clean gutters and downspouts regularly: Proper drainage is your roof’s first line of defense.
   
4. Trim overhanging branches: Snow-laden limbs can break and damage shingles or gutters.
   
5. Address small repairs immediately: A minor leak in December can become major water damage by March.

By keeping on top of basic maintenance and performing a visual inspection of your roof each season, you can spot issues before they compound. When issues do pop up, be sure to contact a professional inspector immediately to determine the next steps. 

FAQs

How can I tell if ice dams are forming on my roof?

Look for large icicles hanging from the eaves, water stains on your ceiling or walls, and uneven snow melt across the roof. These are all common signs of ice dam formation.

Is it safe to remove snow from my roof myself?

You should never climb onto a snow-covered roof. Use a roof rake from the ground to remove excess snow, or hire a professional if buildup is heavy or difficult to reach.

How much snow is too much for a roof to handle?

Most roofs can support about 20 pounds of snow per square foot. Wet, compacted snow weighs much more than fresh powder—if your roof starts to sag or creak, call a roofing expert immediately.