Understanding Roof Drip Edges: What Is It & Why Do You Need It?

A contractor with a harness walking on a roof with brown shingles.

A drip edge is an essential part of a roof flashing system. This innovative product enables homeowners to protect their homes from dangerous hazards including mold, water damage, inclement weather, rotting and insect infestations.

Before we get into specifics about a roof drip edge, let’s take a moment to discuss what it is and why it’s important.

What Are Roof Drip Edges?

A roof drip edge is roof flashing that is installed at the edge of the roofing to cover and protect the seam between the roof shingles and the fascia. They are shaped for easy installation and effectiveness and may sometimes be called edge flashing.

Why a Roof Drip Edge is Important

Siding is a home’s first line of defense from external threats, but by adding a drip edge, although seemingly a small component, a home’s biggest threat is fully defended against: water. Without a drip edge, water is prone to entering the underlying fascia/wall structure and threatens a home’s structural integrity.

The benefits of a roof drip edge include:

  • Protecting the fascia and soffit

  • Closing vulnerable gaps in roofing systems to keep out water and pests

  • When used in conjunction with gutters, disperses water away from the home’s foundation\

Different Roof Drip Edge Materials

A drip edge may also come in a variety of different materials. Each material varies in cost and durability, so it’s important to do research and discuss the options with your client before committing to a material type.


Aluminum is the most commonly used material for drip edges and is the best option for preventing rust. A variety of prefinished colors helps to match the drip edge to your home’s exterior color scheme.


Steel is the strongest material used for drip edges. It’s important to remember that if you want to use unpainted steel drip edges, they must be galvanized — otherwise, they will rust. Steel drip edges are ideal for use in areas of high wind.


Copper is a unique material choice for drip edges that offers an interesting look to homes. The material is very durable and can stand up well to common outdoor hazards, but is also inordinately expensive. Copper currently runs around $7 per pound.

Plastic, Vinyl and Fiberglass

You may find drip edges made from plastic, vinyl and fiberglass in your area, but these materials aren’t well-suited for roofing applications. They can and should be used in other places around the home but don’t provide the protection necessary to protect your roofing system.

How to Install Roof Drip Edges on a Home

The side of a house with white siding and a black roof.

Here’s a step-by-step walkthrough on how to install roof drip edges on a home:

Step 1

Firstly, it’s important to understand that drip edge installation is different for eaves and rakes. After your roof deck has been prepared, and before you install underlayment, you need to install drip edges at the eaves. You install drip edges on the rakes after you install the underlayment.

Then install the drip edges along the eaves by first placing the drip edge onto the eave, aligning it so that water will be rerouted to the gutters. The ends should point away from the roof.

An important note: The drip edge should be installed ¼” to ½” off of the fascia. This is an extremely important step that is often missed by contractors because it seems intuitive to put the drip edge flush with the fascia. If it’s touching, surface tension water will wick up into the fascia, ruining the purpose of the drip edge.

Step 2

To attach the drip edge, install nails every 8 to 10 inches apart — make sure they are high enough on the drip edge to be covered by the shingles. It is also important to check local building codes, as installation may vary by region.

Step 3

As you reach corners where the rake edge and eave meet, make a cut so they’ll fit properly. Mark where the drip edge overhangs and again another inch from the overhang. Then, cut the drip edge entirely at the second mark. Next, create a perpendicular cut and remove a square from the drip edge.

Step 4

Once you’ve made the necessary cuts, install the drip edge normally and then bend in the flap — this allows the drip edge to form a corner.

Step 5

Once the drip edge is completely installed, it’s time to install the underlayment, positioning it right over the drip edge on the eaves. The underlayment (and, ultimately) shingles will lie flush with the drip edge, lining up with the extra ¼”-½” spacing between the drip edge and fascia.

Step 6

Finally, install the drip edge on the rakes. The importance of putting the drip edge over the underlayment on the rake is to seal the edges of the roof and protect from wind-driven rain.

Remember, precision and patience are key to properly installing a drip edge.

How to Install Roof Drip Edges on an Existing Roof

Here’s a step-by-step walkthrough of how to install roof drip edges on an existing roofing system.

Step 1

You’re going to start by gently lifting the shingles off the roof’s edge, which will enable you to locate the nails used on the current drip edge.

Step 2

Using a hammer or a pry bar, remove the nails and the drip edge. Try to be as gentle as possible. This will make the new installation much easier.

Step 3

Once the drip edge has been fully removed, discard and begin the installation of your new drip edge using the step-by-step guide provided above.

Pro Tip: Work with another person who can hold the shingles up while you install the new drip edge.

Why You Should Choose Alsco® Roof Drip Edge for Your Next Project

Are you searching for an affordable and durable roof drip edge provider for your home improvement project? If so, you’ve come to the right place!

At Alsco, we provide top-of-the-line roofing products using the highest quality materials on the market. Contact us today to locate an Alsco supplier near you or to learn more about our incredible product line.