What Is Roof Flashing and How Does It Protect You From Big Leaks?
When most homeowners think about roof protection, shingles and gutters usually come to mind. But there’s another crucial component that often goes unnoticed: roof flashing. Though small in size, flashing plays a big role in keeping your home dry, especially during heavy rain or snow. Without it, even the most well-installed roof can be vulnerable to leaks, water damage and costly repairs.
What Is Roof Flashing?
Roof flashing is a thin layer of metal, usually aluminum or galvanized steel, installed in areas of the roof that are most prone to water intrusion. Its main job is to direct water away from roof penetrations, critical joints, seams or transitions in the roofing system, places where shingles alone can't provide full coverage.
Common flashing areas include:
- Chimneys
- Skylights
- Roof valleys
- Vents and pipe penetrations
- Dormers and wall intersections
- Eaves and rakes
Flashing acts like a weatherproof barrier, guiding rainwater or melting snow away from the seams and into your gutters, rather than into your attic and home.
How Flashing Prevents Leaks
Water is incredibly persistent. It naturally seeks out low points, cracks and any place it can infiltrate. Flashing reinforces vulnerable areas and provides a sealed, angled path for water to flow off the roof safely. Its primary purposes is:
- Redirection: Flashing channels water away from seams, preventing pooling or seepage.
- Sealing Gaps: It closes the space around vents, chimneys and junctions, places where shingles would leave gaps.
- Expansion Tolerance: Metal flashing can flex slightly with temperature changes, helping maintain a water-tight seal over time.
When flashing is missing, damaged or improperly installed, water can seep into your roof deck, attic, insulation and eventually ceiling and walls, leading to mold, rot and serious structural issues.
Types of Roof Flashing
There are several types of flashing used for different parts of the roof. The right type depends on your roof’s layout and the features that need protection.
- Step Flashing: Used where the roof meets a vertical wall (like a dormer), it overlaps like stairs to guide water downward.
- Valley Flashing: Installed in roof valleys (where two slopes meet) to channel water to the gutters.
- Chimney Flashing: A combination of base, step and counter-flashing that seals the chimney perimeter.
- Vent Pipe Flashing: Custom-shaped pieces that surround plumbing pipes or exhaust vents.
- Drip Edge Flashing: Installed along eaves and rakes to prevent water from getting underneath the shingles and damaging the fascia.
- Skylight Flashing: Pre-made or custom pieces that seal the edges of skylights to prevent leaks around the housing.
Signs Your Flashing May Be Failing
Flashing can last for many years, especially when installed correctly, but exposure to harsh weather, temperature changes and corrosion can lead to wear and tear over time. Signs that your flashing may need repair or replacement include:
- Water stains or leaks in your attic or ceiling
- Loose or missing flashing pieces
- Rusted or bent flashing
- Cracked caulking or sealant around flashing
- Shingles curling near chimneys or vents
If you’re seeing any of these issues, it’s important to act quickly before a small problem becomes a major leak.
Why Professional Flashing Installation Matters
Flashing may look simple, but proper installation requires precision, skill and knowledge of your roof’s design. Incorrectly installed flashing is one of the top causes of roof leaks, even on relatively new roofs. A professional roofer knows how to:
- Choose the right type and material of flashing
- Layer flashing with shingles for a watertight seal
- Use proper fasteners and sealants
- Handle tricky intersections and irregular surfaces
- Ensure long-term protection without compromising aesthetics
Our Puget Sound Roofers Have Decades of Experience Properly Installing and Repairing Flashing
At Chet’s Roofing & Construction Inc., we take every detail of your roof seriously, including the flashing. Our experienced team knows how to properly inspect, install and maintain roof flashing to prevent leaks and extend the life of your roof.
Call us at (877) 611-1514 for a professional roof inspection or flashing repair and enjoy peace of mind knowing your home is protected.
