What Is Flashing on a Roof? A Simple Guide

Are You Sure Your Roof Is Leak-Proof? The Hidden Importance of Roof Flashing

If water still seeps inside your roof after a hard downpour despite having a strong roof with high-quality shingles, it may be due to broken or missing flashing. Many homeowners neglect this important part, which can result in mould growth, leaks, and expensive repairs. You can avoid these headaches by being aware of what is flashing on a roof and what it does. The fundamentals of roof flashing, including types, installation and maintenance, will be covered in this tutorial.

What Is Roof Flashing?

Roof flashing is a thin material, typically metal, installed at roof joints to seal gaps where water could sneak in. It’s placed where the roof surface meets vertical structures like:

• Chimneys

• Vents & skylights

• Walls (where the roof meets the siding)

• Valleys (where two roof slopes meet)

Without flashing? Water seeps into your attic, rots wood, and causes mould & structural damage.

Why Is Roof Flashing Important?

Flashing serves as a protective barrier at points where water is most likely to penetrate:

• Roof valleys where two slopes meet

• Chimneys, vents, and skylights

• Edges of the roof

• Junctions where the roof meets the walls

Without proper flashing, these areas become susceptible to leaks, leading to structural damage, mould growth, and interior water stains.

Common Roof Flashing Materials

Different materials are used for flashing, each with its pros and cons:

• Galvanised Steel: Durable and corrosion-resistant, commonly used due to its affordability.

• Aluminium: Lightweight and easy to work with, but may corrode if not coated, especially near masonry.

• Copper: Highly durable and corrosion-resistant, offering longevity but at a higher cost.

• Lead: Malleable and long-lasting, but less commonly used today due to health concerns.

• Rubber or Plastic: Flexible and easy to install, but less durable over time.

6 Main Types of Roof Flashing

Understanding the various roof flashing types helps in identifying and addressing specific needs:

• Step Flashing: Installed where the roof meets vertical walls, such as chimneys or dormers. It consists of multiple pieces that overlap in a step-like fashion to direct water away.

• Continuous (Apron) Flashing: A single piece of metal that runs along the joint between a vertical wall and a sloped roof, directing water down the roof.

• Valley Flashing: Placed in roof valleys to channel water into gutters, preventing pooling and leaks.

• Drip Edge Flashing: Installed along the edges of the roof to guide water into the gutters, protecting the underlying roof components.

• Chimney Flashing: Combines step and counter flashing to seal the area around a chimney.

• Vent Pipe Flashing: Seals around pipes protruding from the roof to prevent water entry.

Flashing Roof to Wall: Installation Basics

Proper installation of flashing where the roof meets a wall is crucial:

1. Clean the Area: Ensure the surface is clean and dry.

2. Install Step Flashing: Place step flashing pieces at each shingle course, overlapping them to direct water away.

3. Secure with Nails: Fasten the flashing to the roof deck, not the wall, to allow for movement.

4. Apply Counter Flashing: Install over the step flashing, attached to the wall, to cover and protect the step flashing.

5. Seal Joints: Use appropriate sealant to ensure a watertight seal.

Improper installation can lead to water infiltration, so it’s often best to consult a professional.

Signs Your Roof Flashing Needs Attention

Be vigilant for these indicators that your flashing may require repair or replacement:

🚩 Rust or cracks in metal flashing
🚩 Loose or bent sections (wind damage)
🚩 Water stains on ceilings/walls near chimneys
🚩 Shingles curling near flashing edges
🚩 Caulk failing (temporary fix—flashing shouldn’t rely on it!)

Regular inspections, especially after severe weather, can help catch these issues early.

✅ Advantages of Proper Roof Flashing

• Prevents Leaks: Protects vulnerable areas from water intrusion.

• Extends Roof Lifespan: Reduces the risk of water damage and associated repairs.

• Energy Efficiency: Prevents moisture-related insulation issues.

• Cost Savings: Minimises potential for expensive structural repairs.

❌ Disadvantages and Challenges

• Installation Complexity: Requires precision; improper installation can cause more harm than good.

• Material Degradation: Exposure to elements can lead to wear over time.

• Maintenance Needs: Regular checks are necessary to ensure ongoing protection.

How Much Does Roof Flashing Cost?

 

Cheap fix now = expensive repairs later. Quality flashing pays off!

Our Solution: Expert Roof Flashing Services

Understanding what is flashing on a house is just the beginning. Ensuring it’s correctly installed and maintained is vital for your home’s protection. Our team of experienced professionals specialises in:

• Assessing Your Roof’s Needs: Identifying areas requiring flashing or repair.

• Using Quality Materials: Selecting the best flashing materials suited to your home’s environment.

• Expert Installation: Ensuring flashing is installed correctly to provide maximum protection.

• Ongoing Maintenance: Offering regular inspections to keep your roof in top condition.

FAQs

What is the purpose of flashing on a roof?

The purpose of roof flashing is to prevent water from leaking into your home at roof joints, valleys, and around roof features like chimneys, skylights, and vents. It directs water away from these vulnerable areas, protecting the structure from moisture damage.

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What does a roof flashing look like?

Roof flashing typically looks like thin, flat metal strips—often made of aluminum, galvanized steel, or copper. It’s shaped and installed at roof intersections and edges to guide water safely off the roof.

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What is another name for roof flashing?

Another name for roof flashing is weatherproofing metal or drip edge (specifically for the roof edge). These terms may vary based on where the flashing is used on the roof.

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Why do they call it flashing?

It’s called flashing because historically, metal was “flashed” or fastened in overlapping pieces to create a continuous water barrier. The term comes from the old practice of layering thin metal sheets for protection against water.

Conclusion

Flashing is a small component with a significant impact on your roof’s integrity. By understanding its importance and ensuring it’s correctly installed and maintained, you can prevent leaks, extend your roof’s lifespan, and protect your home from water damage.

Don’t wait for a leak to take action—contact us today to schedule an inspection and ensure your roof is equipped with the best flashing solutions.