Roof Flashing Tips to Avoid Ice Dam Disasters

Ice dams are one of the most damaging winter roofing problems homeowners face in Rock County and the greater Janesville area. When heavy snow accumulates and fluctuating temperatures cause melting and refreezing, water can back up behind the ice and creep under shingles — often leading to leaks, soaked insulation, interior damage, and costly repairs.

At DMR Exteriors, we’ve seen how many of these issues could have been prevented with one crucial but often overlooked component: proper roof flashing. Combined with solid ventilation and pre-winter maintenance, flashing is your roof’s frontline defense against ice dam disasters.

Here’s what homeowners need to know before winter arrives.

What Roof Flashing Does — and Why It’s Critical

Flashing is the thin metal material installed in vulnerable areas of your roof. Its job is simple: move water away from seams and intersections where leaks are most likely.

Key areas protected by flashing include:

• Chimneys
• Skylights
• Roof valleys
• Pipe boots and vents
• Step flashing along walls and dormers
• Eaves and rake edges

If flashing is loose, corroded, cracked, or improperly installed, water will find its way underneath — and winter only makes the problem worse.

Ice Dams Target Flashing Weak Points

Ice dams form when warm air escapes from the attic and melts the underside of the snowpack. As the meltwater refreezes along the roof edge, water pools behind the dam — often flooding weak points in flashing.

Warning signs your flashing may be at risk:

• Rust or discoloration
• Gaps where metal meets shingles
• Loose step flashing along walls or dormers
• Cracked caulk or missing sealant
• Water stains in attic corners or around chimneys

Fixing these issues before winter is far more affordable than repairing water intrusion later.

Proper Attic Ventilation Reduces Ice Dam Risk

Even perfect flashing can’t compensate for excessive heat loss in your attic. Ventilation plays a major role in preventing ice dams by maintaining a cold roof deck.

Healthy attic ventilation includes:

• Adequate soffit vents for air intake
• Ridge vents or gable vents for exhaust
• Balanced airflow across the entire attic
• Insulation that doesn’t block soffits

If warm air can’t escape properly, your roof warms unevenly — increasing the likelihood of ice dam formation.

Pre-Winter Roof Inspection Checklist

Before temperatures drop, a professional roofing inspection from DMR Exteriors can identify problems early. During a winter-prep visit, we check for:

Flashing Issues

• Loose or lifted step flashing
• Deteriorating chimney flashing
• Storm damage around roof penetrations
• Improperly sealed valleys

Ventilation Problems

• Blocked soffits
• Inadequate ridge ventilation
• Crushed or misaligned insulation
• Signs of heat escape in the attic

Exterior Winter Risks

• Clogged gutters (a leading cause of ice dams)
• Damaged shingles
• Debris buildup in valleys
• Exposed nail heads or fasteners

Early detection helps homeowners avoid expensive emergency repairs during peak winter storms.

Simple Fixes That Prevent Big Winter Problems

Many ice dam issues can be prevented with straightforward upgrades, including:

• Installing ice & water shield under lower roof sections
• Resealing flashing around chimneys and skylights
• Adding heat cables in problem areas
• Improving attic insulation to slow heat loss
• Ensuring gutters drain properly before the first snow

These small investments significantly reduce the risk of winter water intrusion.

Protect Your Home From Ice Dam Damage With DMR Exteriors

Your roof is your home’s first defense against Wisconsin’s winter, and flashing is one of its most important protective components. At DMR Exteriors, we help Janesville-area homeowners prepare their roofs for snow, ice, and freezing temperatures with expert inspections, repairs, and pre-winter maintenance.

Get ahead of winter — schedule your flashing and roof inspection today.

Prevent leaks, protect your home, and enjoy peace of mind all season long.