the importance of Roof Flashing

The Importance of Roof Flashing

Flashings play a crucial role in ensuring that a roof is watertight and protected from moisture damage. Allied Roofing Solutions’ experience in installing and repairing roofs of all types means that we have the knowledge and expertise necessary to ensure that your roof is properly protected against water and moisture damage.

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Benefits of Proper Roof Flashing Installation

One aspect of your home’s roof that is extremely important is the roof flashing. Having the entire roof installed and maintained properly is critical, and one core component is the flashing. The roof flashing is installed in places that are particularly vulnerable to leaking and water damage. Places on the roof that are especially prone to water leakages include the chimney, roof valleys, where a dormer wall and roof surface meet, and skylight perimeters. Roof flashing provides extra protection in these areas.

Allied Roofing Solutions has extensive experience installing and repairing roofs of all types. We understand the importance of flashings that are installed correctly. In this article, we provide information on different types of roof flashing, how they should be installed, why there may be problems, and when you should replace them.

What is Roof Flashing?

Roof flashing is a thin material made of a rust-resistant metal such as galvanized steel, aluminum, or copper which professional roofers use to direct water away from certain areas of the roof. Areas on the roof where the roof plane meets a vertical surface like a chimney, wall, or dormer should have roof flashing as well as other areas like vents and skylights. These are places that require extra protection to avoid leaks and water accumulation that damage the roof’s integrity.

Flashing needs to be installed properly to adequately provide protection. Poor installation can result in roof deterioration, water penetration, and long-term problems. The flashing should overlap the roof-covering material. When your roof is covered in asphalt shingles, it looks better to cover the headwall flashing with a course of shingle tabs.

Types of Roof Flashing

Step Flashing

Step flashing is used against the sides of walls and chimneys. Step flashing is accomplished by placing a piece of metal (the flashing) under each shingle and up against the side of a wall to block the water from running down into it. It is called “step flashing” because the roofer installs it step by step–first laying down a shingle, then a piece of flashing, then another shingle, and then another flashing until the wall is completely protected.

Counter Flashing

Like step flashing, counter flashing is used on walls and chimneys. However, the counter flashing is sawed into an existing mortar joint, and the metal comes over the top of the brick. Counter flashing can be installed in a step-by-step method like step flashing. If you can see the flashing, then it is counter flashing.

Apron Flashing

Apron flashing is used at the base of a wall or penetration. It’s shaped like an L and can be up to 14 feet in length to fit the base of the penetration such as a chimney and dormers to prevent water from getting inside windows.

Installing Roof Flashings

There are several steps involved in installing roof flashings. It is possible to do it yourself, but we recommend hiring a professional team like Allied Roofing Solutions who has the experience to do it right.

Step 1: Underlayment is installed

The first step in installing roof flashings is putting the underlayment under the shingles. The shingles overlay the step flashing. If there are shingles already installed, they must be removed prior to installing the underlayment and flashing.

Step 2: Corner flashing is installed first

Corner flashing is used around walls or dormers that protrude vertically from the top of the roof. Corner flashing is laid down first and then you build the kick-out or step flashing on top of it. It’s best practice to use a prefabricated corner; however, you need to match the exact slope of your roof. If you don’t have access to a prefab corner, you can use the wrapped corner method.

Step 3: The kickout flashing is installed

Next, the kickout flashing is installed, which is at the base of the roof. It adheres to the wall using roof cement or flashing sealant.

Step 4: Place the first shingle

The first shingle goes over the starter strip and the kickout flashing and is secured with roofing cement and a couple of nails.

Step 5: Layering shingles over the flashing

The shingles are installed over the kickout flashing and the first step flashing that has been installed.

Step 6: Repeating Steps 3-4 to create step flashing

Steps 3 to 4 are repeated until the roof’s peak is reached.

Step 7: Custom fitting the flashing at the peak

The flashing is custom-cut to bend over the roof’s peak, creating a curved application that keeps the joint water-tight.

Step 8: Flashing is covered with shingles

Flashing is covered halfway by shingles and half is covered by the siding on your house.

Problems with Roof Flashings

There are many reasons why roof flashing can have problems and fail to perform.

  • Poor installation - When the flashing is not installed properly, it can allow water to seep in and cause damage to the roof.
  • Inadequate ventilation - If the attic isn’t ventilated adequately, it can cause the temperature to fluctuate, causing the flashing to expand and contract. This leads to failure eventually.
  • Climate - When the climate has drastic changes in temperatures–extreme heat in the summer and below freezing in the winter–the flashing can expand and contract too much, weakening the materials and decreasing the effectiveness.
  • Poor maintenance - If gutters get full of debris and aren’t cleaned regularly, the roof is stressed and the flashing can fail.

When to Replace Roof Flashings

The type of weather the flashing has withstood over time also determines if and when it needs to be repaired or replaced. On average, you need to replace roof flashings every 10 to 15 years. The flashing has a lifespan just like your roofing shingles have. As this article has established, because the roof flashing serves such an important function, you should not try to do it yourself. When it is improperly installed, it will not keep the water flowing off the roof as it should. Call a professional roof contractor to replace your flashing. 

Contact Allied Roofing Solutions to Check Your Roof Flashing

If your flashing is ten years old, it’s about time to check on its effectiveness. Our team of professional roofing contractors can perform a roof inspection to see the status of both the roof shingles and flashing. Call us today to schedule an appointment to determine how your roof is holding up. Whether you need a roof repair in NJ or a roof replacement in PA, we are here to provide service at a premium level. We serve New Jersey residents in Bergen County, Essex County, Hudson County, Middlesex County, Morris County, Passaic County, and Somerset County. Call us at  (201) 773-0633 or complete the free estimate form to schedule an appointment.