4 Different Types of Chimney Flashing Explained

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  • 2-8 hours
  • Beginner
  • 20-120

Chimney flashing will help prevent water from leaking into the chimney. Failed or improperly installed flashing is one of the most common reasons for leaks. When it comes to flashing there are many types available. The area you live in, the weather conditions, the shape and size of the chimney, as well as the roofing material will all help determine the best type of flashing for your chimney. Here we'll look at a few types and explain the differences and proper applications.

1. Aluminum Flashing

Aluminum flashing is one of the most common types of flashing. It is inexpensive and can be installed on any type of roof. Aluminum is subject to corrosion, especially when it's installed in areas with treated shingles or lumber. While it's not common to see roofing that is treated with CCA if it is treated with this the aluminum will corrode and fail rather quickly. This type of flashing can be purchased in large rolls and bent and cut to fit any shape. This makes it a popular choice for contractors since it's cheap to buy in bulk and still effective.

2. Vinyl and PVC Flashing

Vinyl flashing is lightweight, and another popular choice for contractors. It's slightly more expensive than aluminum. It's not the best material to use for chimneys, but in areas without harsh weather, it's not uncommon to see. Vinyl can become brittle and result in cracking or breakage, making this a less than ideal material in areas that experience a lot of wet or humid weather. Vinyl is not the best at withstanding high temperatures, another reason it's not very commonly used with chimneys.

3. Steel and Galvanized Steel Flashing

Steel is a heavy material that is commonly used for roofs and chimneys. It is one of the most durable materials to use for flashing. Steel won't corrode as easily as other types of flashing material. Most steel flashing is treated with zinc, and this can corrode before the steel itself will. It is more time consuming since the material is heavier and requires more for installation. Since it is more expensive, it's not something that is typically used for whole roof applications, but it's perfect for chimneys.

4. Copper Flashing

Copper flashing is one of the best materials available for chimney or roof flashing. It is lightweight, resists breaking or cracking, and can withstand high temperatures and extreme weather. Copper is also one of the most expensive materials to use. It can be cost-prohibitive for many people. Copper needs to be installed with a proper sealant that is made specifically for this material. This sealant will create an extra barrier of protection from water seepage. Copper is also not easy to form, making it difficult to use on chimneys with rounded or otherwise difficult angles.