Understanding The Roof Flashing

Roof flashing is a vital protective layer, typically made from metals like galvanized steel, copper, or aluminum. It is installed at intersections such as walls, vents, chimneys, and dormers to form a watertight seal that directs rainwater away from seams and joints. By covering these vulnerable points—placed under shingles or above metal panels—it prevents moisture from penetrating the roof deck and causing leaks.

Types of Roof Flashing

☆Base Flashing

A metal strip placed where the roof meets a vertical surface (like a wall or chimney). It’s covered by another flashing layer, and both can move freely as the roof expands or contracts.

☆Step Flashing

Small L-shaped metal pieces installed along the side of a wall or chimney. They help direct water downward and away from the roof-wall connection.

☆Chimney Flashing

Specialized flashing used to seal the area around a chimney, preventing water from entering where the chimney meets the roof.

☆Counter Flashing

A second layer of flashing placed over step flashing to make sure water can’t get behind it. It’s often used on walls or chimneys.

☆Drip Edge Flashing

An angled metal strip installed along the edges of the roof (eaves and rakes) to direct water into the gutters and protect the roof and fascia.

☆Headwall Flashing

An L-shaped piece installed where a roof meets a wall (headwall). It’s placed behind the wall’s siding and over the shingles to block water.

☆Valley Flashing

A V-shaped or W-shaped flashing installed in roof valleys (where two slopes meet). It channels rainwater safely toward the gutters.

☆Gutter Apron Flashing

A type of eaves flashing that sits under the shingles and over the gutter to prevent water from leaking behind the gutter.

☆Continuous Flashing

A long single piece of metal used to waterproof areas where the roof meets a wall. Also called “apron flashing.”

☆Skylight Flashing

Custom-shaped flashing built to seal the gap between the skylight frame and the roof, keeping water out.

☆Kickout Flashing

Installed at the end of a roof-wall intersection, it “kicks” water away from the wall and into the gutter.

☆Vent Flashing

A collar-like flashing that fits around plumbing vents on the roof. It’s placed under shingles to let water flow around the vent without leaking.

Without properly installed or maintained flashing, water can seep into gaps, leading to interior damage, wood decay, or even structural issues. Common trouble spots include areas around chimneys, crickets, and dormers, where leaks often occur due to damaged or incorrectly fitted flashing.

In summary, roof flashing plays an essential role in preserving the integrity of the roofing system. It helps maintain a dry and secure home by shielding critical points where water intrusion is most likely.