The size of your drip edge matters. Too small, and water will totally bypass the drip edge by leaking right into your shingles. Too large, and it will butt up against other parts of your roof, impairing drainage and giving runoff an easy way to seep into your home.
The International Residential Code (IRC) Section R905.2.8.5 sets minimum standards for drip edge sizing across the United States. This is a great place to start, but it doesn’t really do much to explain how the length of each section, gauge (thickness), and profile factor in.
Learn how to measure your drip edge correctly below so you can lower your risk for leaks and structural damage. We’ll also show you how treating your shingles with Roof Maxx can keep the rest of your roof functioning properly so your flashing can work as intended.
Drip edges are usually sold in 10-foot sections. These standard lengths are faster and easier to install but also hold up better over time because they don’t create as many seams and overlaps. When properly fitted and installed, your drip edge shouldn’t leak, but the risk is always naturally higher where two materials meet.
Shorter 8-foot sections are really only useful for minor repairs or situations where 10-foot lengths won’t fit—for example, dormers, gables, and skylights.
Drip edge width specifically refers to the horizontal section of your flashing that extends back onto the roof and/or under your shingles. To be code-compliant, it needs to measure at least 2 inches, but other options are available:
As long as your drip edge is effectively protecting your fascia and soffits without interfering with the rest of your roofing system, 2 inches is sufficient.
A Note on Residential vs. Commercial Sizes
Commercial drip edges have wider profiles because they’re typically installed on flat or low-slope roofs. They’re heavier, come with a much larger vertical flange, and are usually overkill for homes here in the US.
Drip edges for houses are typically L-shaped, T-shaped, or C-shaped. The shape or profile is different from the type, but differences in terminology can make this a bit confusing. Knowing how to cross-reference each type will help you make the right choice.
All of the sizes listed in the sections below are in Width x Length format.
We’ve included a helpful graphic for each type—comparing these side-by-side makes it easier to spot the main differences. See our in-depth drip edge guide for more info, including how different types and materials stack up.
L-shaped or type C drip edge has a 90-degree bend with a slight outward lip. It’s the most common type used in residential roofing.
T-shaped or type D drip edges have an extra lower flange that forms a “T” shape. This directs water further away from the fascia and your walls.
C-shaped drip edge is specifically designed for standing seam or corrugated metal roofs. It wraps around the entire top and bottom of the roof edge for better protection.
Stuck on the difference between gutter apron and drip edge? See the diagram below!
F-shaped, or gutter apron, isn’t technically a drip edge at all, but it serves the same purpose. It usually has a much larger vertical flange to channel runoff all the way down into the gutter.
Metal drip edge is the industry standard here in the U.S. because it’s better able to withstand the elements, but you have a few options to choose from.
If your fascia or roof is already damaged from past leaks or age, you might need to stick with the standard thickness. Heavier metals put a lot more stress on supporting structures.
Your roof design, the type of shingles you have, and the local climate all influence which type of drip edge is best. Here’s what you might want to look for in different situations:
Lastly, if your roof is in rough shape, you’ll probably want to take steps to improve the condition of your shingles first. A properly fitted drip edge can’t help if you have granule loss and weak points from years of wear and tear.
Shingles naturally lose the oils that keep them flexible and durable over time—but these can be restored to add years of life to your roof. This process is also significantly less expensive than a complete roof replacement.
Roof Maxx’s all-natural plant-based treatment makes aging shingles flexible again so that they can weather the elements. Save up to 80% of what it costs to replace your roof by rejuvenating your shingles this way—so that water continues to flow down your roof and off your drip edges instead of leaking through cracks and causing damage. See how Roof Maxx works.
“Measure twice, cut once” is the DIYers most important rule, but it’s absolutely vital when you’re shopping for drip edges. If you’re even a couple of inches off, it won’t fit correctly—and you might waste money on sections you don’t ultimately need.
Caution! We don’t recommend climbing up on the roof to take measurements like these. It’s safer and easier to call in a roofer, but if you’re committed to tackling the job on your own, please follow proper safety protocols—and never work alone.
If you do intend to try any roofing work yourself, make sure you read this: Roof Fall Protection: How to Stay Safe While on Your Roof
You’ll need these things to access your roof and measure it for drip edge successfully:
Standard fascia boards are 4 to 6 inches tall, so a 2-inch or 3-inch fascia drop usually works.
Struggling with the math? Use this drip edge calculator instead.
Good placement and proper fastening techniques will help lock out leaks and extend the life of your entire roofing system. Follow these best practices to get it right:
Next, we’ll walk you through the most common mistakes people make when they install drip edges—they’re all directly related to these best practices.
Improperly installed or fitted drip edges are the number one contributor to roof leaks. If you don’t install flashing correctly in the first place, water will slowly seep in under your shingles and into the fascia over time. These are the most common mistakes people make:
Making sure your drip edge is installed correctly from day one is the best way to keep it in good working condition over the years.
Properly sized drip edge diverts water away from your roof and down into your gutters, where it can escape into the ground without affecting your home. This helps lower your risk for wood rot, shingle degradation, and costly repairs.
Working with professionals is the best way to make sure your home has the right size and style of drip edge. This will also help you avoid mistakes that could void your warranty or leave vulnerabilities in the finished product.
Choosing the right drip edge is important—and so is preserving your shingles to make sure water can’t leak in through cracks in the asphalt. Roof Maxx’s eco-friendly rejuvenation treatment can help by restoring the natural oils your shingles lose over time. Connect with a dealer in your area now for a free no-obligation quote.
With our five-year, transferable warranty, you’ll enjoy the peace of mind that your roof and entire home are protected.
Roof Maxx Technologies LLC
