Static vent installed on a shingle roof for passive attic ventilation with proper flashing

What is Flashing on a Roof?

8 minutes

When it comes to understanding the various components that make up a roof, flashing plays a vital role in maintaining its integrity and keeping the elements at bay. While often overlooked, flashing serves as a crucial barrier, preventing water penetration and safeguarding against potential leaks. In this article, we will delve into the world of roof flashing, exploring its purpose, what it is made of, types, installation techniques, and the importance of regular maintenance and keeping an eye out for damage to your flashing. Whether you are a homeowner curious about your roof’s construction or a DIY enthusiast seeking to enhance your roofing knowledge, this post will provide valuable insights into the often-underestimated world of flashing. 

What Does Roof Flashing do?  

Roof flashing plays a vital role in protecting the roof from water penetration and potential leaks. Its primary function is to create a waterproof barrier in vulnerable areas of the roof where different materials or roof components intersect. By sealing off these areas, flashing prevents water from seeping into the roof structure and causing damage to the underlying materials and interior of the building. 

Flashing acts as a safeguard against water intrusion in critical areas such as roof valleys, where two sloping roof planes meet, or around roof penetrations like chimneys, skylights, or vent pipes. It redirects water away from these areas and ensures it flows safely off the roof, preventing moisture from seeping into joints, gaps, or crevices.

Furthermore, flashing also helps protect against wind-driven rain and snow. It provides an additional layer of defense by preventing water from being forced beneath roofing materials, which can lead to leaks and water damage. 

Professionally installed flashing is essential for maintaining the long-term durability and functionality of a roof. It helps extend the lifespan of the roof by preventing water-related issues, such as rot, mold, and structural damage. Regular inspection and maintenance of flashing are also important to ensure its effectiveness over time. 

What is Roof Flashing Made of?  

Roof flashing is made of durable materials that are resistant to weathering and corrosion. The choice of flashing material depends on numerous factors such as the roof type, climate, and personal preferences. One commonly used material for roof flashing is galvanized steel. Galvanized steel flashing is popular due to its strength and affordability. It is made by coating steel with a layer of zinc, which provides protection against rust and corrosion. This type of flashing is often used in areas that require high durability and where the flashing will be exposed to harsh weather conditions. 

Another commonly used material for roof flashing is aluminum. Aluminum flashing is lightweight, easy to work with, and highly resistant to corrosion. It is an excellent choice for areas with high moisture content or coastal regions where saltwater exposure is a concern. Aluminum flashing is known for its longevity and ability to withstand extreme temperatures without warping or deteriorating. 

In some cases, copper flashing is also used for its aesthetic appeal and durability. Copper is a premium material that offers excellent resistance to corrosion and has a long lifespan. It develops a natural patina over time, giving roofs a distinct, timeless look. Copper flashing is often seen in historic or high-end architectural projects where aesthetics are a priority. 

What Does Roof Flashing look like?  

Stepped lead flashing roof gulley creating a water tight seal between roof tiles and brick wall .

Roof flashing comes in various forms and shapes, designed to fulfill specific purposes, and accommodate different areas of a roof. 

Step Flashing 

One common type of flashing is step flashing, which is used where a sloped roof meets a vertical structure like a chimney or a wall.

Step flashing consists of small, individual metal pieces that are installed in a step-like pattern. Step flashing provides a watertight seal by overlapping each other and creating a series of steps that divert water away from vulnerable areas. 

Valley Flashing 

Another type of flashing is valley flashing, which is installed in the valleys where two sloping roof planes intersect. Valley flashing is often made of metal and is shaped like a long, V-shaped channel. Its purpose is to direct rainwater or melted snow down the valley and prevent it from seeping into the roof joints. 

Drip Edge Flashing 

Drip edge flashing is another crucial component of a roof. It is installed along the edges of a roof, where the roof deck meets the fascia or the eaves. The drip edge flashing typically has an “L” shape and extends slightly beyond the edge of the roof. It helps redirect water away from the fascia, preventing water damage and rot. 

Chimney with flashing

Vent Flashing 

Vent pipe flashing is used around protrusions such as plumbing or ventilation pipes that extend through the roof. It is designed to create a watertight seal around these openings and prevent water from entering the roof around these vent access points.  

Other Areas of a Roof Where Flashing is Found 

Flashing can also be found around skylights, chimneys, and other roof penetrations. These flashings are specifically designed to fit the contours of the structure they are protecting, ensuring a tight seal, and preventing water intrusion. 

Installing Flashing on a Roof: Is it for the Average DIY’er? 

Installing flashing on a roof can be a challenging task, and it is typically recommended to leave it to professionals unless you have prior experience and knowledge in roofing. While some DIY enthusiasts may feel confident in their abilities, it is important to recognize the complexity and importance of proper flashing installation. Flashing serves as a critical barrier against water intrusion, preventing leaks and potential damage to the roof structure and interior of the home. Improperly installed flashing can lead to serious issues such as water damage, mold growth, and compromised structural integrity.  

The process involves accurately measuring and cutting the flashing material, correctly fitting it around roof penetrations, and ensuring a tight seal to prevent water infiltration. It also requires knowledge of different flashing techniques and an understanding of how flashing integrates with other roofing components. To ensure the long-term performance and protection of your roof, it is advisable to consult with a professional roofer who has the expertise and equipment to install flashing correctly and efficiently such as the #1 top performing roofing contractor: DaBella (according to the Qualified Remodelers annual top 500 report in 2021, 2022, and 2023.)  

When is the Best Time to Replace Flashing on the Roof?  

The best time to replace flashing on a roof is when there are visible signs of damage or deterioration. It is essential to regularly inspect your roof for any indications of flashing issues, such as rust, corrosion, cracks, or loose sections. If you notice water stains on ceilings or walls, dampness in the attic, or experience recurrent leaks, it may be an indication of compromised flashing. In such cases, it is crucial to address the flashing problems promptly to prevent further damage to the roof and the interior of your home. 

Additionally, the age of the roof and flashing is a factor to consider. If your roof is approaching its recommended lifespan, it is a promising idea to inspect and potentially replace the roof & replace the flashing as well. 

Furthermore, if you are planning other renovations or additions to your home, such as installing a new skylight or chimney, it is an opportune time to replace the flashing around these areas.

It is recommended to consult with a professional roofing contractor to assess the condition of your flashing and determine the appropriate time for replacement. They can provide expert guidance and ensure that the flashing is replaced at the optimal time to maintain the integrity of your roof and prevent potential water damage to your home. 

Trust DaBella with Your Next Roof & Flashing Replacement Project 

Ready to ensure your roof is protected with top-quality flashing? Do not leave it to chance – trust the experts at DaBella, the #1 roofing contractor recognized by Qualified Remodeler Annual Top 500 Contractors. With our expertise and dedication to excellence, we guarantee superior installation and the highest level of craftsmanship. Our team utilizes quality-made roofing products by GAF, a leading manufacturer in the industry. As a GAF Master Elite roofing contractor, we have undergone rigorous training and meet the highest standards in the business. Take the first step in safeguarding your roof by calling us today at 844-DaBella. Do not wait until it is too late – let us handle your flashing and roof replacement needs and enjoy the peace of mind knowing your roof is in the hands of professionals you can trust. 

Steven Shortridge

District Manager

Portland, OR

Learn more about Steven