How to Fix a Leaking Roof Around a Chimney: Step-by-Step Flashing Repair

A leaking roof around your chimney can quickly turn from a minor annoyance into a major problem. Water seeping through flashing gaps or worn materials can damage ceilings, walls, and insulation — and even cause mold growth. Fortunately, with the right tools and guidance, you can learn how to fix a leaking roof around a chimney safely and effectively. In this guide, we’ll walk through step-by-step flashing repair methods to help you stop leaks for good. For professional tools, materials, or expert roofing services, check out Pro Found Roofing.

1. Why Chimney Leaks Happen
2. Inspect the Damage Before Repairing
3. Tools and Materials You’ll Need
4. Step-by-Step Flashing Repair Guide
5. Safety Tips and Long-Term Prevention
6. Why Choose Pro Found Roofing for Chimney Repairs

1. Why Chimney Leaks Happen

Most roof leaks around chimneys occur due to damaged or poorly installed flashing — the metal barrier that seals the joint between the chimney and the roof. Over time, weather exposure, corrosion, and roof settling can weaken the flashing and allow water to seep through. Even small cracks in the mortar or roof shingles near the chimney can cause leaks during heavy rain.

Lance Roofing & Siding Inc. / lance roofing and siding

Enon Clark County Ohio

6903 Dayton Springfield Rd, Enon, OH 45323, USA

Common Causes

Some of the most frequent causes of chimney leaks include:

Rust or corrosion in the metal flashing
Cracked or missing caulk around flashing edges
Deteriorated mortar joints on brick chimneys
Poor overlap between step flashing and shingles
Improperly sealed counter flashing

Understanding what caused the leak helps you plan a more durable repair and avoid repeating the problem later.

Holden Roofing (Houston Corporate) / holden roofing

Rosenberg Fort Bend County Texas

2128 1st St, Rosenberg, TX 77471, USA

2. Inspect the Damage Before Repairing

Before diving into repairs, take time to carefully inspect both the interior and exterior of your chimney area. Inside your attic, look for water stains, damp insulation, or wood rot. Outside, examine where the chimney meets the roof — especially under shingles and along metal seams.

Pro Tip

Always perform inspections during dry weather and daylight. Wet surfaces can hide small cracks and make the roof slippery, increasing the risk of accidents.

3. Tools and Materials You’ll Need

Having the right tools ensures efficiency and safety during flashing repair. You’ll need:

Roofing cement or flashing sealant
Galvanized step and counter flashing pieces
Roofing nails and hammer
Utility knife and pry bar
Caulking gun
Wire brush (for cleaning old mortar)
Roofing gloves and safety harness

High-quality roofing materials can make all the difference in preventing future leaks. Pro Found Roofing offers durable flashing products designed to withstand harsh weather conditions.

4. Step-by-Step Flashing Repair Guide

Here’s a detailed process on how to fix a leaking roof around a chimney by repairing or replacing flashing effectively:

Step 1: Remove Old Flashing and Debris

Use a pry bar to gently remove old flashing and nails around the chimney base. Be careful not to damage nearby shingles. Clear out any remaining caulk or debris using a wire brush.

Step 2: Inspect the Underlying Surface

Check for water damage or rot on the roof decking or chimney mortar. If you find any, repair or replace these areas before installing new flashing. This ensures a solid foundation for the seal.

Step 3: Install New Step Flashing

Slide step flashing under each shingle row, ensuring it overlaps the chimney edge by at least two inches. Secure it with roofing nails at the upper edge, not the lower, to prevent leaks from nail holes.

Step 4: Add Counter Flashing

Install counter flashing over the step flashing and embed it into a groove cut into the chimney mortar joint. Seal the top edge with high-quality roofing sealant for added protection against water intrusion.

Step 5: Apply Roofing Cement and Seal Joints

Apply roofing cement where flashing pieces overlap and along any visible gaps. Smooth it out with a putty knife for a clean finish. Allow it to dry fully before exposing the area to rain.

Step 6: Test for Leaks

After completing the repair, spray water over the chimney and roof area with a garden hose for several minutes. Check inside the attic for any signs of leakage. If dry, your repair is complete.

5. Safety Tips and Long-Term Prevention

Working on a roof can be dangerous, so always prioritize safety. Use a sturdy ladder, wear non-slip shoes, and secure yourself with a harness. Never work in wet or windy conditions.

Prevent Future Leaks

Schedule annual roof inspections to catch issues early. Clear debris from gutters and around the chimney to maintain water flow. If your flashing is more than 10 years old, consider replacing it as part of regular maintenance.

6. Why Choose Pro Found Roofing for Chimney Repairs

For homeowners who prefer professional help, Pro Found Roofing offers reliable roof inspection and flashing repair services. Our experts use weather-resistant materials and precision installation to eliminate leaks for good. Whether it’s an emergency fix or preventive maintenance, you can trust our team to protect your home from costly water damage.

By following these steps — and knowing when to call a professional — you can ensure your chimney remains leak-free and your roof stays strong for years to come.