What is Counterflashing on My Chicago Shingle Roof & Why Does It Matter?

If you're a homeowner in Chicago with a shingle roof, you've probably heard the term "flashing," but perhaps "counterflashing" is less familiar. Yet, this often-overlooked component plays an absolutely critical role in protecting your home from water damage, especially around areas where your roof meets a vertical surface, such as a wall or a chimney.

Why is Counterflashing So Important?

Think of your roof's flashing system as a series of overlapping shields designed to shed water. When a shingle roof meets a vertical wall, for instance, step flashing is installed in layers with the shingles, directing water down the roof. However, step flashing alone isn't enough. Its upper edge could still allow water to seep behind it and into your home.

This is where counterflashing comes in. Counterflashing is typically a piece of metal installed over the top edge of the step flashing. It acts as a protective cap, embedding into the vertical wall (often into the mortar joints of brick or beneath siding) and extending down to overlap the step flashing.

Here's why it's so vital:

Protects the "Vulnerable Spots": It creates a critical barrier that prevents water, wind-driven rain, and melting snow from getting behind the primary (base or step) flashing and seeping into your roof deck or walls.

Ensures a Watertight Seal: By overlapping the step flashing, counterflashing works in tandem to create a continuous, watertight seal where your roof meets a vertical obstruction. Without it, even perfectly installed step flashing can fail.

Enhances Longevity: Proper counterflashing extends the lifespan of both your flashing system and your entire roof by effectively diverting water and preventing rot, mold, and structural damage to the underlying components.

Adds Durability: Made from durable materials like galvanized steel, aluminum, or copper, counterflashing stands up to harsh Chicago weather, including heavy rains and snow.

At Anchor Point Roofing, we understand that a truly leak-free roof relies on every component working in harmony. Our expert roof repair services in Chicago include meticulous attention to detail on all flashing components. If you have concerns about leaks around walls, chimneys, or other vertical intersections on your shingle roof, or if you simply want to ensure your counterflashing is up to the task, contact Anchor Point Roofing today for a thorough inspection. We're here to provide lasting solutions and peace of mind.

Location: Chicago, IL