Why Roof Flashing Fails and How to Fix It

The Small Metal Detail That Prevents Big Leaks

Roof flashing might not get the spotlight, but it’s one of the most important elements of a waterproof roof system. Flashing is the thin metal installed around chimneys, vents, skylights, valleys, and roof edges—anywhere the roofing material meets a vertical surface or joint.

When flashing is damaged, loose, or improperly sealed, it’s one of the most common places for roof leaks to start.

🧲 What Causes Flashing to Fail?

Over time, even high-quality flashing can deteriorate. Common causes include:

• Age-related corrosion or rust

• Improper installation or sealing

• Hail or wind damage

• Movement from freeze-thaw cycles

• Settling or shifting of the structure underneath

Sometimes, the problem isn’t the flashing itself—it’s the caulk or sealant around it that has dried out and cracked.

💧 How to Spot Flashing Failure

Warning signs include:

• Water stains on ceilings near walls or chimneys

• Visible gaps or rust in flashing around penetrations

• Shingles lifting near metal seams

• Mold growth in attic corners

These issues often go unnoticed until major water damage has already begun.

🔧 Flashing Repair vs. Replacement

In some cases, flashing can be resealed or re-caulked, especially if it’s relatively new. But if it’s rusted, bent, or improperly installed, it should be replaced.

During a professional inspection, we’ll check:

• Chimney counter flashing

• Step and valley flashing

• Skylight frames

• Pipe boot seals

Flashing should be part of any full roof replacement—and done right, it can outlast the shingles.

🏠 Don’t Let a Small Detail Cause a Big Leak

At Twin Bridge Roofing and Construction, we inspect all flashing components during every job, because we know that’s where leaks love to hide.

📞 Schedule a flashing checkup at (563) 655-4902
🌐 Learn more at www.roofqc.com

One strip of metal could save you thousands in repairs—make sure it’s doing its job.