Your roof does a lot of work to keep your home warm, dry, and protected from the outside elements. But it's not just tiles or shingles doing the hard work. Roof flashings keep the water out and warm air in.
What Are Flashings on a Roof?
Every roof has vulnerable areas. These weaker parts can become entry points for water penetration, without roof flashing. This thin material is designed to prevent leaks from entering through potential weaknesses, like chimneys, skylights, roof vents, pipes, and other roof penetrations. It might also be installed around areas where joins meet, such as a gutter or door and window frames.
Roof flashing is typically made from materials like metal, plastic, or rubber, and is installed whenever the roof meets a vertical surface or protrusion. The flashing materials overlap to create a watertight seal and encourage water to flow away from the roof surface. This weather-resistant barrier system protects your home's structural integrity and longevity.
What Happens if You Don't Have Roof Flashing?
Skipping roof flashing installation or using low-quality flashing can have consequences for your roof's durability. Without it, water can infiltrate weak spots, causing mould, rotting wood, or structural damage within your home.
And the longer you ignore these issues, the more expensive they become to fix, and this can sometimes lead to a complete roof replacement. The solution? Ensure your roof flashing is properly installed (roping in the help of roofing professionals), and use quality roofing materials to give your home the protection it needs.
Benefits of Roof Flashing
- Flashing channels water away from vulnerable areas and prevents water from entering your building and causing damage
- Maintains the structural integrity of your roof and walls by creating a watertight seal to ensure the longevity of your building
- When properly installed, roof flashing reduces the need for regular repairs, making your roof more cost-effective in the long run
- Roof flashing prevents water from accumulating on the roof surface, which improves safety and reduces the risk of accidents when performing maintenance work
What Are the Different Types of Flashing?
There are different roof flashing types for different roofing needs.
- Step flashing: Used along roof edges and walls.
- Valley flashing: Placed in roof valleys where two roof sections meet.
- Chimney flashing: Seals the gap between the roof and the chimney.
- Drip edge flashing: Prevents water from flowing under roofing materials.
- Vent pipe flashing: Seals pipes that penetrate the roof.
- Wall flashing: Protects windows, doors, and points of structural support.
- Apron flashing: Diverts water from vertical surfaces into a gutter.
- Box guttering flashing: Seals edges of a square or rectangular gutter.
What Is Flashing Made Of?
Roof flashing is commonly made from metals like aluminium, copper, galvanised steel, and lead. Metal roof flashings each have pros and cons, and the right roof flashing choice depends on your budget, local climate, and aesthetic preferences. You want your roof to look good, so it's sensible to consider how your roof flashing will fit in with the rest of the building's style.
Aluminium flashing
Lightweight and corrosion-resistant, aluminium is the lightest metal roof flashing and is easy to manipulate. However, aluminium needs a protective coating to prevent degradation, especially in coastal areas.
Copper flashing
Durable and attractive, but expensive. Copper is malleable and particularly good for use around chimneys. Make sure you like the look of discolouration, as the green of aged copper can be a turn-off for some.
Galvanised steel flashing
Cost-effective and strong, but prone to rust over time. Galvanised or pre-painted steel is the most popular metal flashing material. It looks good, is easy to manipulate, and is resistant to corrosion.
Lead flashing
Common for chimneys, thanks to its flexibility and weather resistance. Plus, lead is easily recyclable, making it a sustainable roof flashing choice.
How to Install Roof Flashing
Enlisting roofing professionals who understand health and safety measures and how to follow the building code is always best. The roof flashing installation process can be challenging, so we recommend contacting an experienced roofer.
In essence, the installation process remains the same for most flashing materials. There are three different methods: step flashing (where your sheet metal is layered to form 'steps'), counter flashing (using two separate bits of flashing for chimneys), and vent boot flashing (matching the cylindrical shape of the vent).
Here's a simple guide:
- Prepare the area by cleaning and removing any debris from the roof.
- Cut the flashing to size and make sure it fits the specific area you are working on.
- Secure the flashing using nails or fasteners, ensuring that it overlaps properly to channel water away.
- Use a quality sealant to close any gaps or seams to ensure a watertight installation.
- Inspect your work for any potential gaps or vulnerabilities.
The Importance of Sealant
Your flashing is only as good as your sealant. The sealant fills in gaps and provides an extra layer of water resistance.
You can use high-quality sheet metal roof flashing, but without adhesive sealant, your roof may not be as waterproof as you'd like, especially in areas prone to heavy rainfall or snow.
Final Thoughts on Roof Flashing
Roof flashing may seem like a minor detail, but its importance in protecting your home can't be overstated. Proper installation, choosing the right materials, and regular maintenance can prevent water damage, increase your roof's lifespan, and save you money in the long run.
FAQs
How Much Does Flashing Cost Per Metre?
In Australia, the cost of flashing varies based on the material. Aluminium or Colorbond flashing can cost between $15 to $25 per metre, while copper flashing can cost upwards of $70 per metre - a price tag that reflects its premium quality and durability.
What Type of Flashing Is Best for the Roof?
Copper is considered the best material due to its durability and longevity. However, it's expensive. For a balance between cost and performance, galvanised steel is a popular choice; it's strong, malleable, and resistant to corrosion.
How Thick Is Metal Roof Flashing?
Roof flashing thickness typically ranges between 0.4 mm and 1.2 mm, depending on the material.
Can Roof Flashing Leak?
Yes, roof flashing can leak if it's not properly installed or maintained. Old roof flashing, harsh weather conditions or improper sealant can all age a roof and cause leaks. However, a professional roofer will use high-quality materials and best practices to ensure your roof stays in good shape for many years to come.