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Roof flashings are usually overlooked and can be improperly or poorly installed during roof replacement. Many people don't consider them essential, but in reality, they constitute one of the most critical elements of a roofing system.

Roof flashings are designed to keep the roof airtight and waterproof and provide a seal for the outer envelope that protects your home's interior from weather conditions. In this article, we'll go through everything you should know about roof flashing, including the different types and importance of roof flashings.

Roof Flashing Explained

Roof flashing is a thin metal sheeting layer that directs water away from joints, seams, and other potential areas where water can enter your roof and cause damage. The importance of flashings cannot be overemphasized, and leaks would occur if they were not installed adequately.

Flashings are essential for areas with low points, where the roof surface and walls meet, roof edges, and roof protrusions. They are made from different materials, including plastic, composite, and metal, which can be lead, stainless steel, aluminum, or copper.

Metal sheet flashings are the most durable metal roofing materials for flashings. Copper, for example, offers an excellent level of durability and adaptability to different weather conditions. On the other hand, plastic is a cheaper alternative, but they are prone to wear and tear under harsh weather conditions.

Areas Of The Roof That Need Flashing

The best time to install roof flashing is during the initial installation, which should be done correctly. An improperly installed roof flashing will cause your roofing system to deteriorate quickly. Also, repairing or replacing damaged roof flashing can be challenging.

Therefore, it's vital to ensure that you choose the right material when installing roof flashing on your roof. The material should be high quality, durable, and compatible with your roofing system.

Just as there are different types of roofing systems, there are different types of roof flashing, but it's important to note that they only work well on some roofs. When not properly installed, they can get damaged by different hazards. To avoid these damages, it's essential to know the different areas to install roof flashing, and they include the following:


Continuous flashing pieces are usually applied to create a seal and ensure that water stays around the skylights. Skylights usually extend out of the roof, which makes room for adequate flashing.


Pipes and hoods are the two common types of vents. Hood vents are installed by cutting a hole into the roof to accommodate the vent. Flashings are usually placed above the shingles, which are below the vent, and this is before they are sealed.

Pipe vents are created by cutting holes according to the vent to be installed. Flashings for this type of vent are usually placed such that they overlap with the shingles under the pipe.


Flashing strips are usually placed around chimneys to provide a seal around the roof and the chimney intersection. In this case, the flashing slides under the shingles above the chimney. The flashings also overlap the shingles located at the lower part of the chimney.


This is another structural element that needs the installation of flashings. Dormers project out of the sloping part of the roof, and they usually have windows for more ventilation and light in the upper part of the building. The flashings in this region are installed as multiple square pieces at every shingle row around the dormer.

Types Of Roof Flashing

As mentioned earlier, roof flashings are made from plastic, and metallic materials, including galvanized steel, stainless steel, copper, or aluminum. They are primarily used around gutters, chimneys, doors, windows, and other joints where water runs off.

There are different types of roof flashings, and here's an overview of the common types:

Step flashing and base flashing

These flashes are mainly applied to areas where the roof deck and vertical wall of the building intersect. There are two types of walls; the front walls and the sidewalls. The front walls slope behind a roof deck, while the sidewalls slope along the edge of the roof deck.

Base flashings are ideal for front walls, and they are generally installed under shingles and siding and over an underlayment. On the other hand, step flashings are better suited for sidewalls and are usually kept at a relative angle to the roof pitch. Step flashings allow water to drain safely from the roof.

Valley flashing

Areas where roof decks slope towards each other are referred to as valleys. They create a low line that allows water to flow through and penetrate the roofing system. Valley flashings are installed so that any water can run off the roof edges to the valley and into the gutters.

Chimney flashing

One of the most complicated types of penetration is penetrations like dormers, vents, and chimneys. Each type of penetration has unique installation materials and techniques to provide a tight seal. Even though their flashing requirements are different, the need to waterproof these areas cannot be overemphasized.

Drip edge flashing

Drip edge flashing helps to channel water from the roof edge to ensure that it doesn't go under your roof and cause damage. It's worth mentioning that the drip is vital at the rake edges and the eave edges.

Skylight flashing

This type of flashing is the first protective layer against moisture and leaks. Skylight flashing is generally designed to prevent water from permeating the surface of the roofing material.

Proper installation of skylight flashing is also crucial because, without this, you'll only put your roof at more risk. Skylight flashing keeps you assured that your roof won't leak. Also, the best way to avoid leakage at a skylight is by installing skylight flashing.

Continuous flashing

This type of flashing is installed at the roof's intersection point and sidewall, and they are installed to prevent leaks from this region. However, they are not commonly used because they are not a good option for preventing leaks.

Continuous flashings were designed to offer more protection, but they usually fail to meet up to expectations. If you have continuous flashings on your roofing system, you may need to get a roof replacement quickly.

Kickout flashing

Kickout flashings are also known as diverter flashing because they divert moisture and rainwater from cladding to the gutter system. Correct installation of this flashing helps prevent water penetration into your roofing system.

If you face problems relating to water intrusion from your gutter system, you should consider installing the kick-out flashing without hesitation. Also, a faulty or missing kick-out flashing can result in the accumulation of water, thereby causing damage to your wall.

When To Repair Roof Flashings

As mentioned earlier, flashings are challenging to repair or replace. The process of repairing or replacing flashing is expensive. Getting all the flashings you need when installing a new roof on your property is generally advisable.

In general, the life span of roof flashings is around 40 years, but this is only if they are correctly installed. The cost of repairing roof flashings is up to five times the cost of installing a new one. A lot of added costs are included in the replacement process, including additional labor and time spent removing the faulty flashings.

If you're worried about the quality of your roof flashings, the best thing to do is to get a replacement when you install a new roof on your property. When installed properly, flashings can outlive the average lifespan of a roof, and in this case, they can be reused.

Most roofing contractors will advise you to reuse your flashings if they are still in good condition. However, if they are corroded, have a hole, or show other signs of wear and damage, the best thing is to get an expert roofer to perform a replacement.

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