Leaking Chimney Flashing? (5 Step Repair Guide)

If you’re a homeowner, maintaining your property is likely high on your list of priorities. One common issue for your home exterior is leaking chimney flashing. Over time, even well-constructed roofing systems may encounter this problem, leading to:

• Water damage
• Mold growth
• Other structural issues

Our guide today will walk you through everything you need to know about leaking chimney flashing, from identifying leaks to fixing them effectively.

What is Chimney Flashing?

Chimney flashing is a waterproof barrier that seals the joints between the chimney and the roof to prevent water infiltration. Typically made from materials like aluminum, copper, or galvanized steel, flashing is crucial for ensuring that water does not seep into your home, causing leaks and subsequent damage.

Parts of Chimney Flashing

• Step Flashing: L-shaped pieces that are woven into the shingles and extend up the sides of the chimney.
• Counter Flashing: Installed into the mortar joints of the chimney, covering the step flashing for additional protection.
• Base Flashing: Placed at the base of the chimney, directing water away from the joint between the chimney and roof.
• Cricket (or Saddle): A peaked structure installed behind the chimney to divert water around it.

Signs of Leaking Chimney Flashing

Identifying a leak early can save you a lot of trouble down the road. Here are some common signs of leaking chimney flashing to watch out for:

• Water Stains: Look for water stains on ceilings and walls near the chimney.
• Musty Odors: Persistent damp smells can indicate water infiltration.
• Visible Rust or Corrosion: Check the chimney flashing for any visible rust or wear.
• Peeling Paint or Wallpaper: Water can cause paint and wallpaper to peel or bubble.
• Mold Growth: Mold thrives in damp environments; its appearance is a clear sign of moisture issues.

Common Causes of Leaking Chimney Flashing

Understanding the root causes of leaks can help you address and prevent them:

• Poor Installation: Faulty or rushed installation is a primary reason for leaking flashing.
• Weather Damage: Wind, rain, snow, and temperature fluctuations can cause wear and tear.
• Age: Over time, materials can degrade and lose their effectiveness.
• Cracked Mortar: Cracks in the chimney’s mortar can allow water to seep in.
• Animal Intrusion: Birds, squirrels, and other animals can damage flashing as they attempt to nest.

How to Inspect Chimney Flashing

Regular inspection can help catch problems before they become severe. Here’s how to do it:

• Safety First: Ensure you have a stable ladder and wear non-slip shoes. Safety harnesses are advisable for steep roofs.
• Visual Inspection: Look for any obvious signs of damage, such as rust, cracks, or gaps.
• Water Test: Use a garden hose to run water along the flashing and check for leaks inside the house.
• Interior Check: Examine the attic and areas around the chimney for any signs of water damage.

Tools and Materials Needed for Repairs

Before you begin any repair work, gather the necessary tools and materials:

• Ladder
• Safety harness
• Pry bar
• Roofing cement
• Flashing material (aluminum, copper, etc.)
• Roofing nails
• Trowel
• Mortar mix
• Caulking gun
• Sealant

5 Step Guide to Fixing Leaking Chimney Flashing

Addressing leaking chimney flashing requires some DIY skills, but many homeowners can tackle it themselves.

Step 1: Remove Damaged Flashing

• Access the Roof: Safely set up your ladder and climb onto the roof.
• Remove Old Flashing: Use a pry bar to carefully remove the old flashing. Be cautious not to damage the surrounding shingles.

Step 2: Prepare the Area

• Clean the Surface: Remove any debris, old nails, and remnants of the previous flashing.
• Inspect the Chimney: Look for cracks or damage in the chimney’s mortar and repair as necessary.

Step 3: Install New Flashing

• Install Step Flashing: Cut pieces to size, ensuring they overlap each shingle layer. Secure step flashing with roofing nails.
• Install Base Flashing: Place at the base of the chimney, ensuring it directs water away. Secure with nails and roofing cement.
• Install Counter Flashing: Cut slots into the mortar joints using a grinder. Insert the counter flashing into these slots, covering the step flashing. Seal with mortar and roofing cement.
  Step 4: Seal the Flashing
  • Apply Roofing Cement: Use a trowel to apply roofing cement to all joints and seams.
  • Use Sealant: Apply a high-quality sealant to ensure a watertight seal.
• Step 5: Final Inspection
  • Check Your Work: Inspect all flashing for proper installation.
  • Water Test: Run water along the flashing and check for leaks inside.

Preventive Measures
Preventing leaks before they start is the best course of action. Here are some tips:

• Routine Inspections: Regularly inspect your chimney flashing, especially after severe weather.
• Timely Repairs: Address any minor issues immediately to prevent them from becoming major problems.
• Professional Maintenance: Consider hiring a professional for annual inspections and maintenance.

When to Call a Professional
While many homeowners can handle flashing repairs on their own, there are times when it’s best to call in a professional:

• Severe Damage: Extensive damage may require a pro’s expertise.
• High Roofs: For safety reasons, professional help is advisable for multi-story homes.
• Complex Repairs: If you’re unsure about the extent of the damage or the repair process, consult a professional.

Chimney Leak Repair That Works For You

Leaking chimney flashing can cause significant damage if left unaddressed. By understanding the signs, causes, and repair methods, you can protect your home and ensure its longevity. Regular inspections and preventive measures are key to maintaining your chimney flashing in optimal condition.

If you’re unsure or feel uncomfortable tackling this project yourself, don’t hesitate to reach out to a professional roofing contractor. Your home is an investment worth protecting, and proper chimney maintenance is a crucial part of that.
For more home maintenance tips and guides, stay tuned to our blog and feel free to reach out to our team at Trust Roofing with any questions.