What are the Types of Roof Flashing?
A properly installed roof is made up of several components that work together to keep water outside where it belongs. One of the most important — and often overlooked — parts of that system is roof flashing.
Flashing protects some of the most vulnerable areas of a roof, including walls, chimneys, valleys, edges, skylights, and other roof penetrations. When flashing is missing, damaged, or installed incorrectly, water can work its way underneath the roofing materials and into the home.
That can eventually lead to damaged roof decking, wet insulation, ceiling stains, rotten wood, and expensive interior repairs.
At Restoration Roofing, we believe homeowners should understand what is actually being installed on their home — not just hear a list of unfamiliar roofing terms.
Here are five of the most common types of roof flashing, where they are used, and why each one matters.
What Is Roof Flashing?
Roof flashing is typically a thin piece of metal installed anywhere water needs to be redirected away from a vulnerable part of the roofing system.
Rather than simply trying to “seal” water out with caulk, properly installed flashing is designed to shed water naturally down and away from the structure.
Different roof areas require different flashing details. The flashing used along a vertical wall, for example, is different from the flashing installed in a roof valley or along the edge of the roof.
Some of the most common types found on residential roofing systems include:
- Step flashing
- Counter flashing
- Apron flashing
- Open valley flashing
- Drip edge
Let’s look at each one.
Step Flashing
Step flashing is commonly used where a sloped roof meets a vertical wall.
This might be along the side of a dormer, an exterior wall, or the side of a chimney.
Instead of using one long piece of metal, step flashing is installed in individual sections. Each piece overlaps the one below it and is woven into the shingles as the roof is installed.
The installation typically follows a pattern:
Shingle → flashing → shingle → flashing
That repeating pattern is where the name “step flashing” comes from.
Properly installed step flashing allows water running down the roof or along the wall to continue over the shingles instead of slipping behind them.
This is especially important because roof-to-wall intersections are common locations for leaks when flashing has been improperly installed, covered up, or replaced with excessive sealant.
Counter Flashing
Counter flashing is commonly used with masonry surfaces such as brick or stone chimneys and walls.
It works together with the flashing underneath it.
For example, step flashing or base flashing may protect the lower portion of a chimney connection, while counter flashing overlaps that metal from above.
On a brick chimney, the counter flashing is often inserted into a mortar joint or properly cut into the masonry. This creates an overlapping system that helps prevent water from getting behind the lower flashing.
Think of it as layers of protection.
The lower flashing directs water onto the roof, while the counter flashing helps prevent water from entering from behind or above that flashing.
Chimney flashing is one area where workmanship makes a major difference. Simply applying roofing cement or caulk around the chimney may temporarily slow a leak, but it is not a substitute for a properly designed flashing system.
Apron Flashing
Apron flashing is generally installed at the downslope side of a wall, chimney, dormer, or other roof penetration.
Unlike step flashing, which uses many smaller pieces along the side of a wall, apron flashing is usually one longer section of metal.
It is often shaped so part of the metal runs vertically up the wall or penetration while the lower portion extends out over the shingles.
This allows water coming down the wall or roof surface to flow over the flashing and continue safely onto the roofing material.
A common example is the front side of a chimney.
When rainwater flows down the chimney, the apron flashing at the lower edge helps redirect that water onto the roof instead of allowing it to enter where the chimney meets the shingles.
Apron flashing may also be used in other roof-to-wall situations depending on the design of the home.
Open Valley Flashing
Roof valleys handle a tremendous amount of water.
A valley forms where two roof slopes come together, which means rainwater from both slopes is directed into one relatively narrow channel.
Because of that concentration of water, valleys are one of the most important areas of a roof to install correctly.
One option is an open metal valley.
With this design, a section of metal flashing remains visible between the shingles. The metal creates a durable channel that directs water down the valley and toward the gutter system.
At Restoration Roofing, metal valleys can also be offered as an upgrade on certain roofing systems because of their durability and their ability to move large amounts of water efficiently.
Not every roof uses an open metal valley. Asphalt shingle roofs can also use properly designed closed-valley systems.
The best valley detail depends on the roofing material, roof design, manufacturer specifications, and installation method.
What matters most is that the valley is built to handle concentrated water flow without allowing moisture underneath the roofing system.
Drip Edge
Drip edge is the metal installed around the perimeter of the roof, primarily along the eaves and rakes.
It may not look dramatic, but it serves an important purpose.
Drip edge helps guide water away from the edge of the roof and protects the underlying wood components from moisture.
Along the eaves, it helps direct rainwater toward the gutter rather than allowing it to curl underneath the shingles or behind the gutter.
Along the rake edges, drip edge helps protect the exposed edge of the roof decking and roofing system.
A properly installed drip edge also gives the roofline a cleaner, more finished appearance.
Because it is installed around such a large portion of the roof perimeter, leaving it out or installing it incorrectly can create unnecessary opportunities for water intrusion.
What Metals Are Used for Roof Flashing?
Roof flashing can be manufactured from several different metals.
The most common choices for residential roofing include:
Steel
Steel is widely used because it is strong, durable, and relatively affordable. Prefinished or coated steel can also be selected to coordinate with the color of the roofing system.
Aluminum
Aluminum is lightweight, corrosion resistant, and easy to form around certain roof details. It is commonly used for a variety of flashing applications.
Copper
Copper is generally considered a premium flashing material. It offers excellent longevity and develops a distinctive appearance as it ages.
Copper is often found on higher-end homes, specialty roofing systems, architectural details, and premium chimney flashing applications.
There is no single metal that is automatically right for every situation.
The roofing material, surrounding materials, location of the flashing, appearance, and budget should all be considered when choosing a flashing material.
Should Roof Flashing Be Replaced During a Roof Replacement?
In many cases, yes.
When we inspect a roof for replacement, we also evaluate the condition of the existing flashing.
Older flashing can develop:
- Rust
- Corrosion
- Holes
- Cracks
- Bent sections
- Failed seams
- Improper previous repairs
- Heavy roofing cement or sealant buildup
Flashing that has already been through one or more roofing systems may also be difficult to integrate correctly with a new roof.
For that reason, replacing flashing during a roof replacement is often the best way to ensure that the new roofing system has properly integrated water protection.
There are situations where existing flashing may still be in excellent condition and can potentially remain. However, that decision should be based on an actual inspection — not simply because reusing old metal is cheaper or faster.
A new roof is a major investment. It does not make sense to install brand-new shingles while ignoring deteriorated flashing around one of the roof’s most vulnerable areas.
Why Proper Roof Flashing Matters
A roof leak does not always start because a shingle failed.
In many cases, leaks develop around transitions and penetrations — the places where one roofing surface meets another component of the home.
That includes:
- Chimneys
- Exterior walls
- Roof valleys
- Skylights
- Plumbing vents
- Roof edges
- Dormers
These are exactly the areas where good flashing installation matters most.
Proper flashing is not an optional detail. It is part of the water-management system that allows the entire roof to perform as intended.
Have Questions About Your Roof Flashing?
If you are seeing water stains, loose metal, deteriorated chimney flashing, rusted valleys, or problems around a roof-to-wall connection, it is worth having the area professionally inspected.
Restoration Roofing provides roof inspections, roof repairs, and complete roof replacements throughout Memphis and the surrounding Mid-South.
Our team looks beyond the shingles to evaluate the flashing, valleys, pipe boots, ventilation, decking, gutters, and other components that make up the complete roofing system.
If something is wrong, we will explain what we found and what needs to be done to correct it.
Need your roof checked? Contact Restoration Roofing today.
📞 901-854-3402
🌐 RestorationRoofing.com
