If you ask a child to draw a roof, you usually get a simple triangle perched atop a box with windows. In real life, a roof is much more complex than those three scribbled lines. Your roof has multiple components that help it protect your home, vent air, and shed moisture. One of those components is the drip edge. Let’s look at what a roof edge does and why it is a critical component of your home’s roof.
What is a Drip Edge?
A drip edge is a metal flashing piece installed at the outer edge of your roof often bent into an “L”-shape. It creates a small overhang that funnels water out and slightly away from the horizontal surfaces below, allowing rainwater to run off without damaging your home. The drip edge channels water run off into your gutters or, in some cases, directly to the ground below.
Typical roof drip edge overhangs are two to five inches. Residential roofing companies can determine the appropriate size and style drip edge for your roof style and the local weather conditions. There may also be local building codes that stipulate drip edge requirements.
Made of aluminum, steel, copper, or other non-staining and corrosion-resistant materials, drip edge flashing is waterproof and long-lasting.
Drip edges are relatively inexpensive but highly impactful in preventing water and wind damage. That makes them an essential part of your roof system. They are included with most new residential roofs and can be retrofitted onto older existing roofs.
Purposes of a Drip Edge
Your drip edge serves two purposes in the protection of your home.
1. Redirecting Wind-Driven Rain
Your shingles protect your roof deck, channeling water down your roof and off of your home. This redirection works well with vertical rain. However, if a strong wind forces the rain to hit your roof at an angle, that water can work its way under the sides of the shingles.
Imagine an umbrella that keeps you dry in a vertical rain. Now imagine a heavy wind is pushing that rain. While your top half will stay dry, suddenly, you are getting wet in areas previously protected by the umbrella.
Your shingles work similarly to that umbrella. They will protect the top of your roof from angled rain, but at the edges, the wind will push the water up under the singles’ protection, leading to leaks and water damage. Your drip edge acts as a seal for the edge of your roof, closing off the area that would otherwise be open to water pushed by the wind.
2. Protecting Fascia from Water
Your drip edge takes advantage of the slightly cohesive nature of water. Because water tends to stick to itself, the drip edge can pull water into your gutters and off the fascia–the vertical surface at the roof’s edge. If you don’t have gutters, the drip edge pulls the water away from the fascia so that it drips to the ground below instead.
Without a drip edge to pull and guide water away, wetness clings to your shingles and fascia, leading to rot, mold, or leaks into your home.
Why Do You Need a Drip Edge?
In addition to being a requirement in many building codes, drip edges protect your roof and home. We already discussed how a drip edge channels water away from your roof. Here are some other ways it protects your home:
Improved Gutter Performance
The drip edge helps your gutters be more effective and efficient. Creating a continuous flow of water aids the gutters in removing rain from your roof system. The drip edge also protects your gutters, keeping out dirt and debris that might damage the gutter system. That means your gutters work better and need less frequent cleaning.
Protection from Invasive Creatures
The seal created by a drip edge doesn’t just keep out water. The same gaps that would have let in the rain also allow insects or small animals to access your roof deck and your home. The drip edge seals off this access point.
Icicles can wreak havoc on your roof. The drip edge forces icicles to form on it rather than on the less sturdy, more vulnerable roof fascia or shingles.
Drip Edge Profiles
There are three common types of roofing drip edges.
1. Type C
It would make more sense if this were called “Type L .”With a ninety-degree bend and a lower flange at the bottom, type C drip edge flashing resembles the letter ‘L.’ In fact, while “type C” is the more common name, occasionally you will hear it referred to as “L style.”
2. Type F
Also called “F style” or “gutter apron,” Type F drip edges have an extended leading edge, causing them to hang further away from the roof. That makes them suitable for installing over existing shingles or rake edges. Sometimes, a Type F drip edge extends past the gutter, so runoff is sent directly to the ground rather than into your gutters. That’s why Type F drip edges are sometimes called a gutter apron.
3. Type D
Type D drip edges are shaped like the letter “T .”At the bottom, they have a lower flange. This shape helps Type D drip edges, also known as “T style” or “D metal,” channel the water further away from the fascia.
It’s easy to overlook your roof’s drip edge. However, roofing contractors know they play a vital role in roof systems. Thanks to that little piece of metal at the edge of your roof, your roof can better protect your home from the elements, and your roof will last longer.