Expert Flashing Repair in Southwest London

Chimney Flashing Repair – All Work Guaranteed. Battersea Power Station The Engine Room London

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Need Chimney Flashing Repaired?

If you've experienced chimney leaks, noticed rust around your fireplace, or seen water stains near your chimney, it's time to take action. At Knights Roofing, our skilled team offers professional chimney flashing repair services to protect your home from water damage and costly structural issues. Read more here about why chimney mainenance is so important.

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chimney breast leak, chimney crown leak, chimney flashing leak, chimney leaking repair, chimney leaning
chimney breast leak, chimney crown leak, chimney flashing leak, chimney leaking repair, chimney leaning

What Is Chimney Flashing and Why Does It Matter?

Chimney flashing is a thin sheet of metal installed at the intersection where the chimney meets the roof. Its primary purpose is to create a watertight seal, preventing rainwater from seeping into your home.

Without proper flashing—or if the flashing becomes damaged—water can leak into your attic, walls, or ceilings, leading to mold, wood rot, and even structural damage.

 

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Types of Chimney Flashing

Aluminum

Pros: Aluminum is affordable, resistant to rust, and suitable for most roof types.
Cons: It may corrode when in contact with certain building materials, such as treated wood or concrete.

Galvanized Steel

Pros: This material is durable and cost-effective, making it a common choice for many applications.
Cons: Over time, galvanized steel can rust, especially if its protective zinc coating is damaged.

Copper

Pros: Copper is long-lasting, highly resistant to weathering, and adds a visually appealing aesthetic to buildings.
Cons: It is the most expensive option among the materials listed.

PVC/Vinyl

Pros: PVC or vinyl is a low-cost material, making it budget-friendly.
Cons: It is only suitable for use in warm climates and is prone to cracking in colder weather.

When to Repair Your Chimney Flashing

Properly installed flashing can last up to 30 years, but various factors (like weather exposure or improper installation) can shorten its lifespan. It's time to schedule a repair if you notice:

  • Leaks near the chimney or inside the fireplace
     
  • Dripping sounds or puddles near the hearth
     
  • Rust spots around the chimney base
     
  • Stained walls or ceilings near the chimney
     
  • Visible cracks or gaps in the flashing sealant
     

Even if you're not seeing signs inside your home, chimney flashing should be inspected regularly—especially after severe weather.

 

How to Repair Chimney Flashing: The Process

Our professionals follow a step-by-step approach to ensure your chimney is properly sealed:

1. Inspect and Diagnose

We examine the condition of your existing flashing to assess the damage—cracks, corrosion, poor sealing, or structural gaps.

2. Prepare the Area

We clean the flashing area, remove old caulk or sealant, and clear away any debris to ensure proper adhesion.

3. Repair or Replace

  • Minor Gaps: Sealed with silicone or high-heat roofing sealant
     
  • Major Damage: Remove old flashing and install new materials (base, step, and counterflashing)
     

4. Secure the Seal

We fasten the flashing securely and reinforce the seal with premium caulking to prevent leaks.

5. Final Inspection

We test the repairs, check for leaks, and ensure the seal is weatherproof and watertight.

DIY chimney flashing repair is risky and typically requires climbing on a roof. For safety and effectiveness, we highly recommend professional service.

Cost of Chimney Flashing Repair

The cost to repair or replace chimney flashing can vary based on several factors, including the type of material used, the size of the chimney, the slope of the roof, and how extensive the damage is.

  • Basic repairs, such as minor sealing, typically cost between $200 and $300.
  • Full flashing replacement for a metal chimney usually ranges from $300 to $500.
  • For brick or stone chimneys, the cost is higher, often between $500 and $1,000 or more, due to the complexity and materials involved.
  • Large chimneys with multiple flues or vents can cost anywhere from $1,000 to $1,500, depending on the scope of the work.
     

In addition to material and project-specific costs, labor rates also influence the total price. These typically range from $75 to $100 per hour, varying by location and the complexity of the job.

Should You DIY or Hire a Pro?

While small flashing issues may seem manageable, professional repair ensures long-term protection, safety, and compliance with local building codes.

Hire a trusted company like Knights Roofing to:

  • Ensure correct materials and installation
     
  • Detect hidden damage or leaks
     
  • Safely work at heights
     
  • Provide a warranty on the repair
Quotation Mark

Professional service repairing our roof, good value, would recommend.

Mr Bennett, Wimbledon

Complete chimney repointing and roof repair at our property to a very high Standard.

Mr and Mrs Howe, Clapham

Repaired our lead flashing and completed maintenance work to our leaking roof, great job.

Daniel, Richmond

chimney breast leak, chimney crown leak, chimney flashing leak, chimney leaking repair, chimney leaning

Why Choose Knights Roofing?

Knights Roofing knows the importance of maintaining your property's health and safety. That's precisely why we provide an extensive chimney repair solution aimed at ensuring your chimney remains in optimal condition. Our company also has valid certificates FSC and PEFC

Don’t let faulty flashing threaten your home—schedule your chimney inspection today and receive a free estimate.

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FAQs: Chimney Flashing Repair

Q: What is chimney flashing?

It’s a metal barrier that seals the intersection between your chimney and roof, preventing water from leaking into your home.

Q: How do I know if my flashing is damaged?

Look for rust stains, dripping water, wet ceilings near the chimney, or visible gaps in the flashing.

 

Q: Can I patch chimney flashing myself?

 

Minor patches are possible, but most repairs require expertise in roofing and chimney systems. It's safer and more effective to hire a pro.

Contact us for Chimney Flashing Repair!