What is roof flashing and why does it matter?

March 8, 2023 by

The roof of your home is one of the most important components when it comes to protecting your family and property from the elements. When it comes to building a durable and reliable roof, the devil is in the details. Every component of a roofing system, from the shingles to the flashing, plays an important role in protecting your home from the elements. While it may not be the most glamorous aspect of roofing, roof flashing is an essential part of any roofing system and plays a critical role in keeping your home safe from water damage.

Roof flashing is a thin, impermeable material (often made of thin metal) used to seal joints, seams, and other areas where roofing materials meet walls, chimneys, vents, or skylights. It helps prevent water infiltration by providing a waterproof seal for many types of roofs including metal, tile, and asphalt roofs.

A professional roof contractor will be able to install roof flashing correctly so that it can provide years of protection for your home. It’s an essential part of any roof installation or repair job – yet many homeowners overlook its importance until it’s too late. In this post, we will discuss the different types of flashing available, how flashing should be installed by professional roofers, and what you need to look for during inspections or repairs.

Types of roofing flashing

Roof flashing comes in a variety of different types and materials. Each type of flashing is designed for a specific area of the roof where water is likely to penetrate, and choosing the right type of flashing is crucial to ensuring a waterproof seal. Here are some of the most common types of roof flashing:

  • Base Flashing – Base flashing is the roof flashing material laid down before the shingles.
  • Step flashing or Apron flashing – Step or apron flashing is installed around the edges of roofing systems and roof penetrations, such as chimneys and skylights. It’s designed to create a watertight seal where the roof intersects with vertical walls.
  • Drip edge flashing – Drip edge flashing is installed along the edge of the roof to prevent water from seeping under the shingles and into the building envelope. It helps to direct water away from the roof and into the gutters.
  • Valley flashing – Valley flashing is installed in the valleys of a roof, where two sloping roof planes meet. It helps to direct water down the roof and into the gutters.
  • Ridge cap flashing – Ridge cap flashing is installed at the peak of the roof to prevent water from seeping under the shingles and into the building envelope. It helps to create a watertight seal at the highest point of the roof.
  • Vent pipe flashing – Vent pipe flashing is installed around vent pipes to create a watertight seal where they penetrate the roof. It helps to prevent water from seeping into the building envelope and causing damage.
  • Counter flashing – Counter flashing is installed on masonry walls and is designed to cover and protect the step flashing. It helps to prevent water from seeping into the building envelope where the roof intersects with the wall.

Roof flashing can be made from a variety of different materials, including aluminum, copper, lead, and galvanized steel. Each metal flashing material has its own benefits and drawbacks, and the choice of material often depends on the specific needs of the roofing system. Roof flashing materials are designed to create a watertight seal in a specific area of the roof where water is likely to penetrate. Choosing the right type of flashing material is essential to ensuring that the roofing system remains durable over time.

How is roof flashing installed?

Proper installation of roof flashing is crucial to ensuring a watertight seal and protecting your home from water damage. Generally, flashing installation follows this process:

  1. Prepare the area: A roofing contractor will clean and prepare the area where the flashing will be installed. This may involve removing old flashing, debris, and any other obstructions that could prevent the flashing from creating a secure seal.
  2. Measure and cut the flashing: Once the area is prepared, the flashing is measured and cut to the appropriate size and shape. It’s important to ensure that the flashing fits snugly and covers the entire area where it will be installed.
  3. Apply sealant: Before installing the flashing, a layer of roofing cement or sealant is applied to the area to help create a watertight seal. This sealant should be allowed to dry before installing the flashing.
  4. Install the flashing: The flashing is then installed, starting at the bottom of the area and working upward. Each piece of flashing is secured in place with nails or screws, and overlapping pieces are secured together with roofing sealant.
  5. Finish the installation: Once the flashing is installed, the edges are trimmed and any remaining gaps are filled with sealant. The flashing is then inspected to ensure that it is securely in place, creating a weatherproof seal.

It’s important to note that the specific installation process for flashing can vary depending on the type of flashing and the specific area where it is being installed. For example, step flashing around a chimney may require additional steps, such as bending the flashing to fit the shape of the chimney and installing counter flashing to cover the step flashing.

In general, proper installation of flashing requires skill and experience, and it’s typically best left to a professional roofing contractor. A professional roofer will have the tools, materials, and expertise necessary to install flashing correctly and ensure that it provides effective protection against water damage.

Inspecting for damage to flashing

Regular inspection of your roof flashing is important to ensure that it is functioning properly and protecting your home from water damage. Your flashing may be damaged if you notice the following:

  • Signs of water damage: Water stains or damage to insulation can be a sign that water is seeping in through the roof, vent or skylight, which could indicate a problem with the flashing.
  • Visible damage to flashing: Look for cracks, dents, rust, or other signs of damage that could compromise the flashing’s ability to create a watertight seal.
  • Check for secure attachment: Check that the flashing is securely attached to the roof and any adjacent structures such as skylights. If it appears loose or wobbly, it may need to be re-secured.
  • Check for gaps: Inspect the areas where the flashing meets other roofing materials, such as shingles, and look for gaps or spaces where water could penetrate.
  • Look for missing flashing: Check that all areas of the roof that require flashing have it installed. Missing flashing leaves the roof vulnerable to water damage.

If you notice any signs of damage or wear during your inspection, it’s important to address the issue promptly. Damaged flashing can allow water to penetrate the roofing system and cause damage to the structure of the home. In many cases, it may be necessary to replace the damaged flashing to ensure that the roof remains watertight.

It’s important to note that while regular DIY inspection is important, it’s also important to hire a professional roofing contractor to inspect your roof at least once every three to five years. Gunner offers free roof inspections and can help to identify issues that may not be immediately visible to an untrained eye, ensuring that your roof flashing and overall roofing system is in tip-top shape!

 

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