Flashing is a key roofing element. It plays a vital role in protecting your Alpha, NJ home from leaks. You’ll find flashing along your roof’s edges and around all roof protrusions. This thin layer of sheet metal surrounds skylights, dormer openings, exhaust vents, and chimneys. Flashing keeps moisture out and directs runoff toward your gutters and landscape drainage.

The Role of Flashing in Roofing

Residential roofs have multiple layers. For instance, if you have an asphalt shingle roof, your shingles sit atop a thin underlayment and a watertight ice and moisture barrier. With this multi-layer design, if a shingle falls off or any other component fails, your home will maintain a modest amount of temporary leak protection.

Flashing is one of the many layers that make up your roof. It’s installed in all areas most vulnerable to water leaks. You’ll find it in any space where a horizontal plane meets a vertical surface. In addition to your roof’s protrusions and edges, flashing is also installed at all roof valleys or areas where two sections of roofing meet. Without flashing, water would eventually make its way into the crevices at these junctures and enter homes.

Not only does flashing provide a physical barrier against moisture, but its slick surface and angled position prevent water from pooling. Flashing directs water onto asphalt shingles, and the tiny, pebble-like granules on asphalt shingles move it toward downspouts and gutters.

Flashing at Front and Side Walls

Flashing or flashings are also installed at all front and side walls. These are the areas where roofs connect with buildings. Here, flashing prevents water from seeping behind siding, saturating insulation, and creating problems like blistered paint, discolored walls and ceilings, and warped materials in the building interior.

What Happens When Flashing Fails?

Damaged or failing flashing means more than just the loss of leak protection. Damaged flashing can also lead to serious issues with mildew and mold, pest infestations, and loss of home efficiency.

Mold and Mildew Development

When flashing isn’t snug and watertight, moisture can slip into tiny gaps and permeate building materials. While other moisture barriers exist, slow and hidden flashing leaks will eventually overcome these barriers and cause problems in attics, behind siding, and in drywall and wood framing. According to the Centers for Disease Control (CDC), wet building materials can develop mold spores within just 48 hours of moisture exposure.

If left unchecked, flashing leaks can even create changes in indoor humidity. According to the United States Environmental Protection Agency (EPA), when indoor humidity rises above 60%, indoor mold proliferates. Thus, flashing damage can additionally have a significant impact on your indoor air quality (IAQ) and resident health.

Pest Infestations

Certain insects love wet building materials and pockets of moisture. Not only do they provide a generous supply of water, but they also create the perfect breeding grounds for egg-laying insects. If you have unchecked flashing damage on your home, you have a much higher likelihood of developing ant, mosquito, and wasp infestations. Perpetually wet wood features can even attract cellulose-loving termites.

Progressive moisture damage weakens roofing materials and makes it easier for climbing animals to create points of ingress. Torn flashing around chimneys and exhaust vents will eventually provide entrance for rodents and other pests seeking concealed shelter.

Decreased Home Efficiency

Just behind your home’s siding lies a thick mat of insulation. This insulation keeps warm, conditioned air trapped inside during the winter months and prevents hot outdoor air from seeping in during summer. It helps lower your heating and cooling costs and keeps your household’s carbon footprint in check.

Unfortunately, most insulation types can lose 50% or more of their insulating abilities when saturated. If you have torn flashing at your front or side walls or near dormer openings and eaves, you could have wet insulation behind your siding and in your attic. Worse still, wet insulation in these areas can take a long time to dry out, even when flashing isn’t actively leaking.

Sagging Building Elements and Premature Roof Failure

The moisture damage caused by flashing leaks is progressive. The longer that you neglect a flashing repair, the more your home will suffer. You can eventually expect to see warped, bowed, and sagging wood elements. You can also expect your roof to have a significantly shorter lifespan overall. Moreover, an unchecked flashing leak can mean the difference between needing a basic roof replacement and having to replace portions of your home’s rough framing as well.

What Are the Most Common Causes of Flashing Problems?

After every severe storm, it’s best to schedule a storm damage inspection. Extreme weather events take a toll on all roofing elements, including flashing. Flashing is also prone to sustaining age-related wear, damages caused by repeated temperature fluctuations, and changes in its integrity due to foundation problems.

Seasonal Temperature Fluctuations

When exposed to high temperatures, flashing expands. It contracts when the mercury plummets. These temperature-related movements wear flashing down over time. They can also loosen flashing to create leaks. This type of damage has the highest likelihood of occurring when flashing is nailed too tight to accommodate temperature-related movement.

Foundation Cracks

Foundation problems can affect your home all the way to its topmost layer. If you have a slab leak, shifting soils causing settlement issues, or other foundation problems, these could cause your flashing to warp and crack over time.

Hail, Falling Branches, and Other Heavy, Hard-Hitting Items

Hail is hard-hitting, fast-moving, and often quite heavy. On average, the state of New Jersey experiences just two hailstorms a year, and they’re rarely long-lasting or extremely destructive. However, even small hail can create indentations and gaps in flashing that impact its moisture-blocking abilities.

If you have low-hanging trees in your yard, be sure to prune them regularly. Pruning or limbing trees eliminates dead, diseased, and weak limbs and branches before they come crashing down on roofs.

Strong Winds

Strong, heavy winds can pull flashing back to create visibly lifted or torn sections. Strong wind can also create tiny, inconspicuous gaps between flashing and building materials that allow moisture in.


Flashing is frequently comprised of metals like galvanized steel, copper, or aluminum. However, some roofing companies also use durable plastic flashing at roof valleys and in other highly conspicuous areas. All flashing has a finite lifespan. Fortunately, this lifespan often matches or exceeds the average lifespans of roofs themselves. Thus, if your flashing is experiencing age-related failure, there’s a good chance that your roof is ready for replacement, too.


Animals are far smarter than people give them credit for. Climbing animals that are known to infest attics, HVAC air ducts, and various aspects of roofing systems recognize roofs’ weak points. Whether because flashing is bright and reflective or easy to transgress, many climbing animals take advantage of these features to enter homes.

Just as flashing damage can lead to pest infestations, aggressive pests can cause flashing problems where none existed before. Even when pests don’t intentionally pull or tamper with flashing, fast-moving animals like heavy raccoons can have an impact on flashing’s integrity.

This makes it important for all homeowners with low-hanging trees to practice diligent pest management. While pest treatment is performed to eliminate existing infestations, pest management is everything that homeowners do to preventatively ward off animals and insects that naturally thrive within the local environment.

Your Trusted Roofing Professionals

We proudly serve residents of Alpha, NJ and the surrounding communities with top-notch roof repair, replacement, maintenance, and storm damage services. We also provide expert siding, gutter, and commercial roofing services. If you have flashing problems, give Warren Thompson & Son Roofing & Siding a call now.

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