When homeowners in Chicagoland think about roof problems, shingles often take the spotlight. Curling, missing, or cracked shingles are easy to notice and are commonly blamed for roof leaks. But what many don’t realize is that one of the most critical components of a roof—and one of the first to fail—is the roof flashing.
Flashing is the thin layer of protection that seals some of the most vulnerable parts of your roofing system. And when it starts to fail, the effects can be far-reaching. At Sammy’s Roofing, we’ve seen everything from attic leaks in Evanston bungalows to major interior water damage in historic homes on Chicago’s South Side, all caused by deteriorating or poorly installed flashing.
So what exactly is flashing, why is it so important, and what makes it one of the most common sources of roof failure? Let’s break it down.
Think of roof flashing as your home’s unsung hero. It’s not as visible as your shingles or gutters, but it plays an essential role in protecting your property from water damage. Flashing is typically made of metal—often aluminum or galvanized steel—and is installed in areas where your roof intersects with other features of your home. These areas include the base of chimneys, around roof vents, skylights, valleys where two roof slopes meet, and along any vertical wall that joins the roof.
These intersections naturally create small gaps or seams, which are especially vulnerable to water intrusion. Without flashing, water would find its way into these openings every time it rained or snowed. Flashing works by directing that water away from the joint and down the slope of the roof, where it can safely run into your gutters and away from the home’s foundation.
This small piece of metal is what keeps moisture out of places it absolutely doesn’t belong—like your attic insulation, drywall, and electrical systems. In cities like Chicago and Aurora, where the climate swings from freezing winters to humid summers, flashing is even more critical. Ice dams, heavy snow, and rapid thawing can all put stress on your roof system, and flashing is on the front lines of defense.
Despite its importance, flashing is frequently one of the first roofing elements to fail. This happens for several reasons, and in our years serving homeowners across Chicago neighborhoods and suburbs like Oak Park, Naperville, and Evanston, we’ve encountered them all.
One major factor is exposure. Flashing is placed in the most weather-vulnerable areas of the roof. Over time, exposure to wind, rain, snow, and UV rays causes flashing to expand and contract. This thermal movement can eventually warp the metal or break the seal between the flashing and the roof. Once gaps form, water starts creeping in unnoticed until visible damage shows up inside the house.
Installation is another big issue. In our experience, we’ve found that many older homes in places like Evanston or Berwyn have flashing that was installed incorrectly—or in some cases, not installed at all. Improper nailing, lack of sealant, or using the wrong material can make a roof look fine from the outside while silently failing beneath the surface.
Even flashing that was properly installed can become compromised due to shifting building materials. Roof decking, framing, and masonry all expand and contract over time, especially with the dramatic seasonal changes we see in the Chicago area. That movement can pull flashing loose or open small gaps that give rainwater a perfect entry point.
Then there’s simple aging. While shingles might be rated for 20 to 30 years, flashing often wears out faster, especially if it was made from thinner material or wasn’t adequately maintained. We’ve repaired dozens of homes throughout Aurora and suburban Cook County where the shingles still looked good, but the flashing had rusted through or lifted entirely.
If your flashing is failing, the signs might not be obvious right away. Many times, homeowners in places like Skokie or the West Loop only realize something’s wrong when they notice a water stain on the ceiling or wall. But by the time that stain appears, the water has usually been leaking for quite some time, slowly damaging insulation, drywall, and even structural wood framing.
Other warning signs include rusted or visibly lifted flashing around chimneys or vent pipes, cracked mortar joints near flashing points on brick chimneys, or even shingles that appear misaligned or buckled near flashing seams.
Because flashing issues are subtle and slow-moving, they’re often misdiagnosed. We’ve been called out for “roof leaks” that were actually small flashing gaps letting in water during wind-driven rain. On a calm day, the roof seemed fine. But every time a storm rolled through, moisture found its way inside.
Many homeowners delay flashing repairs, especially if the leak seems minor. Unfortunately, that decision can lead to much more serious—and expensive—repairs down the line.
In our time working throughout the greater Chicago area, we’ve seen flashing failures that led to rotted decking, mold growth in attic spaces, and even damage to electrical systems when water dripped onto ceiling-mounted fixtures.
Fixing a flashing problem early might involve replacing a few feet of metal and resealing a joint. Letting that same problem go unchecked for months could require removing large sections of roofing, replacing sheathing, and addressing interior water damage—all of which can multiply your repair bill.
At Sammy’s Roofing, we take flashing seriously. Whether we’re doing a full roof replacement in Chicago or a simple repair job on a two-story home in Elmhurst, we inspect and test all flashing points during our work.
When we install new flashing, we use high-quality, corrosion-resistant materials that are built to handle Chicagoland’s challenging weather. We also make sure flashing is properly integrated with the roofing underlayment, not just surface-sealed with caulk or roofing cement. And in cases where a home has older brickwork or custom trim, we ensure the flashing is tailored to the structure—no shortcuts, no “one-size-fits-all” solutions.
For homeowners with newer roofs who want peace of mind, we also offer flashing inspections and maintenance plans. These regular checkups can help catch early signs of wear or loosening before a leak develops. This service has been especially popular in areas like Downers Grove and Oak Lawn, where older homes are being updated with modern roofing materials.
The flashing challenges we see in Chicagoland are very much shaped by our region’s climate. Homes near Lake Michigan, including neighborhoods like Rogers Park or Hyde Park, are more susceptible to wind-driven rain and ice buildup. Homes in western suburbs like Naperville or Glen Ellyn may face more frequent freeze-thaw cycles that put extra stress on roofing seams.
That’s why it’s so important to work with a local contractor who understands the unique conditions your home faces. At Sammy’s Roofing, we’ve worked on everything from classic Chicago two-flats to brand-new suburban builds. We know what materials hold up best, where weak points typically occur, and how to address problems that are specific to your type of roof and your area.
If you haven’t had your roof inspected recently—or if you’ve noticed signs of water damage and can’t pinpoint the cause—flashing could be the culprit. It’s a small detail that has a big impact on your roof’s performance and your home’s safety.
Don’t wait until a small leak becomes a major repair. The sooner flashing problems are identified and fixed, the better protected your home will be against costly water damage.
Call Sammy’s Roofing today to schedule a comprehensive roof inspection in Chicago, Aurora, Evanston, or anywhere in the greater Chicagoland area. We’ll check all flashing points, explain what we find, and recommend the right fix to keep your roof watertight and worry-free.