Do you have a commercial or residential property with a pitched roof? If so, then you likely have some form of roof flashing installed. But what exactly is roof flashing, and why is it important? This guide will answer those questions and more, giving you a comprehensive overview of everything you need to know about this essential component of your roofing system.

What Is Roof Flashing?

Roof flashing is any material (usually metal) used to create a water-resistant barrier around potential water entry points on a roof. This can include valleys (where two slopes meet), chimneys, skylights, vents, and anything else that protrudes from the roof. It can also seal the joints where different roofing materials meet.

Flashing is essential because it helps to prevent water damage. Water is the number one enemy of roofs, and even a small amount can cause serious problems down the line. When water gets into your roof, it can lead to leaks, rot, and mold growth. Over time, this can weaken the structure of your roof and lead to costly repairs or even replacement.

Properly installed roof flashing helps prevent water leaks by providing a barrier against the elements. It also helps extend the roof’s life by protecting it from exposure to sunlight and wind.

Roof Flashing Types

Different types of flashing can help extend the roof’s life by keeping water from pooling on top of the shingles. Water pools on the roof can cause the shingles to deteriorate and eventually fail. Flowing water away from the roof and into the gutters helps keep the roof in good condition.

The most common types of roof flashing include:

1. Continuous Flashing

Continuous flashing is a type of roof flashing with another name as “apron flashing.” This flashing acts similarly to an apron by providing a long, single piece of metal that carries water down to the shingles present below. It is typically made from galvanized steel or aluminum and can be either pre-formed or custom-made to fit the specific needs of a particular roofing project.

2. Base Flashing

Base flashing is used around features like chimneys to ensure that rain always meets a flashing surface and is directed downward. It is notoriously difficult to install, but it is essential for preventing water damage to your home.

3. Counter Flashing

The flashing helps to complete the seal between the base flashing and the roof surface, preventing water from seeping in and causing damage. Opposite to base flashing, the counter flashing has above placement and helps to create a watertight seal. This is especially important in areas where the roofline meets a wall, chimney, or another type of structure.

4. Step Flashing

The rectangular piece of flashing is present over the wall surface and then bending in the middle to form a 90-degree angle. This allows water to flow away from the wall and prevents it from seeping in. You can use multiple layers of step flashing to provide better protection against water damage.

5. Skylight Flashing

Manufacturers design skylight flashings in aluminum sections to provide for an expansion joint between the skylight window or skylight and the roof covering material. Doing so, they also help to protect your roof and skylight from taking in water, which could lead to a leak.

You can install them around the skylight’s perimeter and extend them onto the roof surface. Install them according to the manufacturer’s instructions and ensure that they are compatible with the type of roofing material.

6. Drip Edges

A thin metal flashing that allows water to drip off the roof edge is a drip edge. This is important because it prevents water damage to the home or causing a leak. Having a drip edge helps to protect your investment and keep your home in good condition.

7. Valley Flashing

Valley flashing is critical to your roofing system and must be at least 24 inches (610 mm) wide to protect your home from water damage. It is installed over open roof valleys and helps direct water flow away from vulnerable areas. Check your local building code for thickness requirements, as they can vary depending on location.

8. Kickout Flashing

Roofing experts generally use kick-out flashing to bridge the gap at the end of step flashing. This flashing directs water away from the wall and into the gutter. It will prevent water damage when water seeps behind the siding or trim and leaks into the home.

Roof Flashing Materials

Several types of materials can be used for roof flashing, each with advantages and disadvantages.

1. Copper

It is perhaps the most traditional choice for roof flashing and has excellent durability and weather resistance properties. It is malleable and can be easily formed into the desired shape, making it a good choice for complex roof designs. However, copper can be pretty expensive and may require more maintenance than other options.

2. Aluminum

Aluminum is another popular choice for roof flashing, as it is relatively inexpensive and easy to work with. However, aluminum is not as durable as copper and may react with different elements. But it can be coated to help protect it from the elements, and it can be a good choice for areas that do not see severe weather conditions.

3. Stainless Steel

When it comes to roof flashing, stainless steel is one of the most durable and long-lasting materials you can choose. Stainless steel won’t corrode or degrade over time, making it an ideal material for areas that are exposed to the elements. Stainless steel is an excellent choice if you’re looking for a material that will stand the test of time.

4. Galvanized Steel

Galvanized Steel is a popular choice for roof flashing because of its durability and resistance to corrosion. It can be used in exposed and recessed applications and is available in various thicknesses and widths to meet your project needs. When selecting galvanized steel for your roof flashing, consult with a qualified contractor or engineer to ensure it is the suitable material for your application.

Roof Flashing Techniques

Roof flashing is essential in any roofing system, as it helps keep water out of the building. Many different techniques can be used for roof flashing, and the technique used will depend on the particular application.

1. Step Flashing

Step flashing is one of the most common and practical techniques for installing roof flashings. It involves attaching individual pieces of flashing material to the edges of each shingle, starting at the bottom edge of the roof and working up.

It is where each shingle course is overlapped by the next one up, and a strip of metal is placed between the two to direct the water away from the wall. This way, even if some water does get past the shingles, it will be caught by the metal and directed away from the wall.

2. Plumbing Vent Boot Flashing

The flashing consists of a cylindrical piece of metal that fits around the vent pipe itself. The shingles are then installed over the base or “boot” of the flashing. The height of the boot is has design to force water to run around the vent pipe rather than into the building. Hence, properly installing plumbing vent flashing is critical to preventing water damage.

3. Counter Flashing

The flashing typically consists of the base flashing and the counter flashing itself. The base flashing is installed around the base of the chimney (or other structure), and the counter flashing is embedded into the chimney’s masonry. This second piece sits over the base flashing and helps prevent water from seeping in behind the base flashing.

In addition to using around chimneys, you can use counter flashing for other purposes such as sealing off windows or doors.

Installing roof flashing can be a tricky process, so it’s essential to follow instructions carefully. If you’re not comfortable doing it yourself, hire a professional to do the job for you. Improperly installed roof flashings are one of the leading causes of leaks and water damage in homes. So, be sure to avoid it and seek help from Roofing Texas Pros professionals.

How Is Roof Flashing Installed?

Installing roof flashing can be a complex process, and it is best left to a professional roofer. Here are some general steps to install counter flashing or any other type.

  • First, the area around the point of water entry must be prepared. 
  • It usually involves removing existing flashing material and ensuring the surface is clean and level. 
  • Next, the new flashing material is cut to size and installed. 
  • Once the new flashing is in place, it must be sealed properly to ensure a watertight seal.

Roof Flashing Maintenance

Proper maintenance is essential to keeping your roof flashings in good condition.

  • Inspect your flashings at least once a year for any signs of damage, such as cracks, rust, or loose nails. If you find any damage, repair it immediately to prevent water from leaking into your home.
  • You should also clean your roof regularly to prevent dirt and debris from clogging the drainage holes.
  • When choosing a roof flashing material, it is crucial to consider its durability, resistance to weathering, and ability to blend in with your home’s existing exterior.


Is Roof Flashing Necessary?

Roof flashing is necessary if you want to protect your home from water damage. Flashing is installed around openings in the roof, such as vents, chimneys, and skylights. It helps to direct water away from these vulnerable areas and prevents leaks.

What Is The Purpose Of Flashing On A House?

The purpose of roof flashing is to keep water out of your home. It is installed around openings in the roof and helps direct water away from these vulnerable areas. Also, it helps to prevent leaks.

How Much Does Flashing On A Roof Cost?

The cost of roof flashing varies depending on the material you choose and the size of your roof. However, you can expect to pay anywhere from $50 to $500 for roof flashing.

Does A New Roof Include Flashing?

Most new roofs will include some flashing, but it is always best to check with your contractor to be sure. If your contractor does not have flashing in the price of your new roof, you may want to find another contractor.

How Long Should Roof Flashing Last?

Roof flashing should last as long as your roof lasts. However, checking your flashing for any signs of wear and tear is always a good idea.

What Is A Roof Drip Edge?

A roof drip edge is a metal strip installed along your roof’s edges. It helps keep water from running under the shingles and onto the fascia board or into the house. The drip edge also gives the roof a finished look and helps prevent wind damage.

Should Flashing Be Painted?

You don’t need to paint it, but you may want to paint it to match the color of your home. If you paint your flashing, be sure to use high-quality paint designed for metal.

Should Flashing Be Caulked?

No, you should not caulk roof flashing. Caulking is for filling gaps and cracks, and roof flashing should never have any gaps or cracks. The only time to use caulking in conjunction with roof flashing is if the flashing is made of a material incompatible with the roofing material, such as lead flashing on a slate roof. In this case, you can use a thin bead of silicone caulk to create a seal between the two materials.

Can I Install Roof Flashing Myself?

It is possible to install roof flashing yourself, but it is best to leave this job to a professional contractor. Roof flashing requires special tools and skills; making mistakes that could lead to serious problems is easy.


In conclusion, roof flashing is a vital component of any roofing system. It helps to protect the roof from water damage by directing water away from the structure. There are many different types of roof flashing available on the market, so choosing the one that best suits your needs is essential. If you are unsure about roof flashing type, consult with a professional roofer. We’d be happy to assist.

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Last Updated: July 21, 2022 / Categories: Construction & Renovation, Roofing & Gutters / 10.2 min read / Tags: , /

About the Author: Shaun Wright

Shaun Wright

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