What Is Chimney Flashing in Residential Roofing?

If you own a home in Colorado, protecting your roof from water damage is critical—especially around your chimney. One small area that can cause big problems is your chimney flashing.

Let’s break it down.

What Is Chimney Flashing?

Chimney flashing is the metal (usually aluminum, galvanized steel, or copper) installed where your chimney meets your roof. Its job is simple but vital: keep water from leaking into your home at this joint.

Chimney flashing typically includes:

• Step flashing: L-shaped metal pieces layered with shingles up the chimney sides.

• Counter flashing: Installed into the brick or mortar to cover the step flashing.

• Cricket (or saddle flashing): A ridge built behind large chimneys to divert water.

Without proper flashing, even a well-installed roof will leak.

Why Chimney Flashing Matters in Colorado

Colorado weather is rough on roofs—sun, snow, ice, wind, and hail all in one year. Flashing is often the first defense in preventing water intrusion, especially with ice dams in winter and wind-driven rain during storms.

Bad or missing flashing leads to:

• Leaks in the attic or ceiling

• Rotten wood and mold behind walls

• Chimney brick damage

• Higher heating bills

Signs You Need Chimney Flashing Repair

Keep an eye out for:

• Water stains on the ceiling near your chimney

• Rusted or loose flashing visible on the roof

• Cracked brick or mortar around the chimney

• Shingles pulling up near the chimney base

If you see any of these, it's time to call Roof Nuts CO at 303-276-2403.

Repair vs. Replacement: What to Expect

Sometimes flashing just needs resealing with roofing cement. But often, especially if it's more than 15–20 years old or poorly installed, full replacement is smarter.

Here’s what a professional repair may involve:

• Removing old flashing and inspecting wood deck underneath

• Installing new step and counter flashing

• Sealing with roofing-grade caulk or solder (for copper)

• Ensuring proper integration with roofing and chimney materials

All flashing work should meet current IRC/IBC codes and follow NRCA installation guidelines.

Best Flashing Materials for Colorado Homes

• Aluminum: Affordable and rust-resistant, but not ideal near masonry unless coated.

• Galvanized steel: Common, cost-effective, but eventually rusts.

• Copper: Premium choice. Long-lasting, looks great, and doesn't corrode. Perfect for upscale homes or historic properties.

FAQs

What causes chimney flashing to fail?

Most often, it’s poor installation, age, or weather damage. Thermal expansion and freeze/thaw cycles common in Colorado cause cracking over time.

How long should chimney flashing last?

With proper materials and installation, it can last 20–30 years. Copper can last even longer.

Can I repair chimney flashing myself?

Small repairs may seem DIY-friendly, but it’s easy to miss underlying damage. Always get a pro to inspect and quote the work—especially in storm-prone areas.

Need Chimney Flashing Help in Colorado?

If you’re in Denver, Colorado Springs, Fort Collins, or anywhere nearby, we’re ready to help. At Roof Nuts CO, we specialize in permanent roofing solutions—including chimney flashing done right the first time.

Call us at 303-276-2403 or visit RoofNutsCO.com to schedule an inspection.