Ideally, the best way to keep your residential, commercial or industrial building watertight is to install all roofing materials as part of a continuous, unbroken surface. However, in reality, construction of the vast majority of buildings calls for the creation of some sort of roof opening. Unfortunately, every single opening cut into the surface of a roof functions as a potential entry point for water and a source of leaking. To prevent water entry at these vulnerable points, roofers rely on material called flashing. Let’s examine the importance of flashing in further detail.
Flashing is the collective term for any type of thin, waterproof material designed to prevent water from infiltrating a roofline. Common examples of the materials used for this purpose include polyethylene and other plastics, modern composite substances and metals such as stainless steel, lead, copper and aluminum. Generally speaking, plastic flashing has the shortest functional life, while copper and other metals have the longest. However, any properly installed materials will hold up well for extended periods of time. Most professionals install metal products by preference.
Flashing is put in place during the initial roof installation process. Once installed, it can be quite difficult to repair or replace. For this reason, conscientious roofers place an emphasis on doing the job right the first time. Of course, unexpected circumstances can lead to minor or major damage in even the most perfectly completed flashing installation. When seeking repair or replacement help in such situations, look for qualified professionals in your area with extensive, verifiable roofing experience.
Where Is Flashing Installed?
In a well-constructed building, flashing is installed in various places throughout the roof. Specific areas that require use of this material include:
- Vent Openings – Residential, commercial and industrial roofs frequently feature two types of vents: pipe vents and hood vents. Each of these openings requires its own form of flashing installation. Today, many roofing professionals protect pipe vent openings with single-piece, boot-like flashing products that extend from the side of the pipe to the surrounding section of the roof.
- Skylight Openings – Skylight openings are often quite large, and unless properly secured they present rainwater with an easy pathway into the interior of your home or business. For maximum protection, professional installers typically try to install a continuous strip of flashing around the entire opening.
- Dormer Openings – Dormers are construction features that project out from the surface of a slanted roof and provide you with extra interior space and/or improved air circulation. They exist in a variety of sizes and formats, and may or may not come outfitted with windows. Creation of a dormer naturally requires a corresponding break in the roofline. Flashing is installed to seal the gaps between the edges of the dormer structure and the primary roofing material.
- Chimney Openings – In any building outfitted with a chimney, the chimney opening also creates a potential leak trouble spot. To prevent problems, roofers commonly install two sections of flashing, known as the base flashing and the counter flashing. One end of the base flashing is inserted under the shingles (or other roofing materials), while the other end extends up the bottom of the chimney itself. The counter flashing sits on top of the base material and is securely attached to the chimney.
Openings aren’t the only parts of your roof that require flashing for the creation of a weathertight seal. Additional areas that need to be covered during the installation process include:
- Roof Valleys – Roofers use the term “valley” to refer to any place where two or more parts of a multi-plane roof meet at a downward angle. Each side of any given valley is made from a different section of roof decking. Flashing plays a vital role by covering the gaps between the decking sheets and preventing water entry throughout the joint.
- Roof Edges – Roof edges are also susceptible to leaking. This typically occurs when water drips down from the outer roofing material and works its way beneath that material, the underlying sheet of decking or the fascia board that helps form the face of the roof eave. Roofers prevent this from happening by installing a form of flashing called a drip edge, which juts out at the bottom and directs dripping water away from the building.
During installation, a roofing professional may choose different types of flashing materials for different areas of your roof. For example, many professionals favor copper flashing — which is both strong and highly flexible — to seal complex valley joints on multiple-plane roofs. With the wealth of materials available today, there’s a product suitable for essentially every possible roofing layout.
When Flashing Fails
Flashing failures rank among the most common causes of roof leaks. This means that if you notice the signs of interior leaking, you should definitely include damaged flashing on the list of potential underlying causes. If you’re an experienced repair do-it-yourselfer and you know how to follow best practices for maintaining safety, you can potentially get up on your roof and troubleshoot the problem on your own. However, if you have any concerns at all about your abilities, it makes much more sense to contact a local roofing expert who can do the job for you.
The same rule applies to flashing repair and replacement. Not all of this work is complicated, and you could potentially tackle straightforward jobs yourself. However, unless you’re sure you know what to do, your DIY “solution” may only end up costing you money and damaged property later on down the line. For reliable results, turn to a professional roofer like Tom Byer Roofing.