The Critical Importance of Strategic Flashing Placement

When a homeowner in Washington, Wildwood, or Chesterfield invests in a new roof, the focus is often on the shingles. While the shingles provide the primary aesthetic and a bulk of the protection, the real “MVP” of any roofing system is the flashing. Flashing placement is the strategic installation of thin pieces of impervious material typically galvanized steel, aluminum, or copper designed to prevent water from entering the structure at intersections and joints.

In the roofing world, we have a saying: “Water always finds a way.” Without expert flashing placement, even the most expensive designer shingles will not protect your home from the heavy downpours common in Pacific or the melting snow in Union. At RC Roofing, we treat flashing as the most technical and vital stage of the entire installation process.

Why Flashing is the Vulnerable Point of Your Roof

A roof is rarely a single, flat plane. It is interrupted by chimneys, skylights, dormers, and valleys where two roof slopes meet. These “interruptions” create seams. Because gravity pulls water downward, these seams act as natural funnels. If the flashing placement is even a fraction of an inch off, water will seep behind the shingles, rotting the wooden decking and eventually dripping into your insulation and drywall.

Common Areas Requiring Precision Flashing:

• Chimneys: Perhaps the most notorious source of leaks.
• Dormer Walls: Where a vertical wall meets a sloped roof.
• Valleys: Where two roof planes intersect to form a “V” shape.
• Plumbing Vents: The pipes that exit your roof for sewage ventilation.
• Skylights: Beautiful for light, but a disaster if not flashed correctly.

Types of Flashing and the Art of Installation

Professional flashing placement involves different techniques depending on the specific geometry of the roof. At RC Roofing, we utilize a multi-layered approach to ensure a watertight seal in communities like Frontenac and Town & Country.

1. Step Flashing

Used where a roof meets a side wall. We install individual L-shaped pieces of metal with every course of shingles. This “stepping” ensures that water is shingled from one piece of metal to the next, eventually shedding onto the main roof surface.

2. Counter-Flashing

For masonry chimneys in Augusta or Eureka, step flashing isn’t enough. We perform “counter-flashing,” where a second layer of metal is embedded into the mortar joints of the brick and hangs down over the step flashing. This creates a “cap” that prevents water from running down the face of the brick and getting behind the roof line.

3. Valley Flashing

Valleys handle more water than any other part of the roof. In high-wind areas like Chesterfield, we prefer “open valleys” with heavy-gauge W-shaped metal flashing. This provides a smooth, unobstructed path for water and debris to flow directly into the gutters.

4. Drip Edge Flashing

This is installed along the eaves and rakes of the roof. Its job is to direct water away from the fascia board and into the gutter. Proper flashing placement at the drip edge prevents the “wicking” effect, where water clings to the underside of shingles and rots the edge of your roof deck.

How Missouri Weather Tests Flashing Integrity

Missouri’s climate is particularly harsh on metal components. From the intense UV rays in Washington to the sub-zero temperatures in Wildwood, the materials on your roof are constantly expanding and contracting.

Thermal Expansion and Sealant Failure

If flashing is nailed too tightly or if the wrong sealants are used, the metal will buckle as it heats up in the summer. This can pull fasteners loose or create gaps. Our flashing placement experts use high-grade solar-stable sealants and allow for the “breathing” of the metal, ensuring the seal remains intact through 100-degree temperature swings.

The Ice Dam Threat

In Pacific and Union, ice dams can cause water to back up under the shingles. If the flashing around a chimney or dormer isn’t integrated with a high-quality ice and water shield (a self-adhering membrane), that standing water will find the seam and enter the home. We overlap our flashing with these membranes to create a “bulletproof” barrier.

The Consequences of Poor Flashing Placement

Many “discount” roofing contractors try to save time by reusing old flashing or using excessive amounts of caulk to hide poor metalwork. This is a recipe for disaster for homeowners in Eureka and Town & Country.

• Structural Rot: Flashing leaks are often “slow leaks.” By the time you see a brown spot on your ceiling, the rafters and decking may have been rotting for months.
• Mold Growth: Damp attics are the perfect environment for mold, which can compromise the air quality of your entire home.
• Voided Warranties: Shingle manufacturers require proper flashing placement for their warranties to remain valid. If a leak is caused by poor flashing, you likely won’t be covered for any material damage.

The RC Roofing Standard for Metalwork

At RC Roofing, we don’t just “install” flashing; we craft it. We understand that every home in Frontenac, Augusta, and Chesterfield is unique.

Our Quality Assurance Process:

• Custom Fabrication: When off-the-shelf flashing won’t provide a perfect fit, we custom-bend our metal on-site to ensure a seamless match for your roof’s specific angles.
• Material Compatibility: We never mix certain metals (like copper and aluminum) because “galvanic corrosion” can cause them to eat through each other. We ensure all fasteners and flashing materials are chemically compatible.
• Double-Check Inspections: As part of our roof quality control, we perform a “hose test” on complex flashing areas to verify they are 100% watertight before we leave the job site.

Aesthetics Meet Function

While the primary goal of flashing placement is protection, we also care about how your home looks. We offer flashing in various colors and finishes to match your shingles or trim, ensuring that your roof is as beautiful as it is durable.

Final Thoughts: Protecting the Joints of Your Home

Your roof is only as strong as its weakest point, and that point is almost always a joint or a transition. By prioritizing professional flashing placement, you are closing the door on water intrusion and extending the life of your home’s interior. Whether you are in Washington, MO, or any of our surrounding communities, don’t let a small piece of metal become a big financial headache.