When a crew tears off your old roof, the first thing they install isn’t a shingle—it’s a roofing starter strip. It’s easy to overlook, buried under the first course of shingles and hidden from view once the job is done. But this small detail is the difference between a roof that lasts 20+ years and one that fails prematurely, leaking water into your attic and rotting your decking.
In this post, we’ll explain exactly what a starter strip is, why it’s critical to roof performance, and what homeowners should watch for when a roofing crew gets to work.
What Is a Roofing Starter Strip?
A roofing starter strip is a specialized adhesive strip installed along the lowest edge of your roof—the eaves—before the first full course of shingles. It’s typically 7–9 inches tall and runs the entire perimeter of your roof’s bottom edge.
Think of it as a foundation for your shingles. While standard shingles have adhesive tabs designed to bond to the shingle below them, the starter strip is engineered to bond directly to the roof decking (the plywood underneath). This creates a secure anchor point that keeps wind from lifting the edges of your first course of shingles—the point of greatest stress during storms.
Starter strips are made from asphalt and granules, similar to architectural shingles, and they’re typically darker in color to remain visually neutral once covered. They’re not just a nice-to-have; modern building codes require them on virtually all residential roof installations.
Why the First Course of Shingles Matters Most
Your roof’s first course of shingles takes the most damage. Here’s why:
Wind pressure is focused at the eaves. When storms pass over your home, wind doesn’t push evenly across the entire roof surface. Instead, it creates uplift—a vacuum-like pressure that pulls hardest at the edges, particularly at the eaves. A properly installed starter strip transfers this load to the decking itself rather than relying on the bond between the first course and second course of shingles.
Water drainage starts at the bottom. Rain and melted snow flow down toward the eaves. Any gaps or loose edges in that first course allow water to penetrate behind the shingles and into the decking, eventually reaching the attic and causing interior leaks and rot. A secure bottom edge keeps water moving toward the gutters and away from your home.
Granule loss happens first at the edges. The eaves experience more temperature fluctuation and UV exposure than the rest of the roof. Without a proper starter strip, the bond between the first course and decking deteriorates faster, causing premature granule shedding and accelerating the timeline to replacement.
At Edwards & Sons Roofing, we’ve inspected thousands of roofs across the St. Louis and Metro East area, and the failures we see most often trace back to one of two things: improper starter strip installation or no starter strip at all.
How Starter Strips Contribute to Roof Performance
A quality starter strip does four essential things:
1. Anchors Shingles Against Wind Uplift
The adhesive on a starter strip is formulated to bond aggressively to roof decking. When wind tries to lift your first course of shingles, that bond transfers the pressure to the decking itself—which is fastened directly to your home’s structure. Without this anchor, wind can peel the first course back like a page in a book, exposing the decking and creating an entry point for water.
2. Creates a Complete Water Seal at the Eaves
A properly installed starter strip ensures there are no gaps or voids at the edge of your roof. Water flowing down the roof plane hits the starter strip’s adhesive seal and is directed into the gutter, not behind your shingles. This is why the bottom edge is the most critical sealing point on your entire roof system.
3. Prevents Blow-Offs During Storms
Hail and high winds are common across Illinois and Missouri during spring storm season. We’ve seen roofs lose entire first courses of shingles because the starter strip was missing or improperly installed. A correctly installed starter strip prevents this catastrophic failure, which is why insurance companies often require proof of proper installation before approving a claim.
4. Extends the Life of Your First Course
By maintaining a secure, weather-tight seal at the eaves, the starter strip reduces the stress on your first course of shingles. This means less granule loss, a longer lifespan for that critical layer, and fewer leaks during the roof’s peak performance years.
What to Look for When Your Roof Is Being Installed
If you’re having a roof replaced, here’s what a quality installation looks like at the eaves:
The starter strip runs the entire perimeter. It should cover the full width of every eave, valley, and edge where the first course will be installed. No gaps, no shortcuts. Any break in the starter strip is a vulnerability.
Fasteners are placed correctly. While the adhesive does most of the work, the starter strip should be fastened with roofing nails spaced 8–12 inches apart along the top edge. These nails keep the strip in place during installation and before the first course of shingles seals it down.
The starter strip is beneath the first course, not visible. Once the first course is installed, you shouldn’t see the starter strip from the ground. If it’s visible at the edge, it may have been installed incorrectly or at the wrong angle.
Drone photos document the installation. Professional contractors often photograph the bare roof decking and starter strip installation before the first course goes down. This creates a record of quality work and is invaluable if you ever need to file an insurance claim. We send our customers drone photos of every stage of the installation so they can see exactly what’s happening on their roof.
Common Mistakes in Starter Strip Installation
We’ve seen these common mistakes:
Mistake 1: Installing the starter strip upside down. The adhesive needs to face the decking. If it’s reversed, the bond fails almost immediately. This is rare but catastrophic.
Mistake 2: Skipping the starter strip entirely. Some contractors cut corners to reduce costs. This is a violation of building code and a guarantee of premature failure. Never hire a contractor who suggests skipping this step.
Mistake 3: Using old or damaged starter strips. If the adhesive has been exposed to heat or weather before installation, its bonding strength is compromised. Quality contractors use fresh materials from climate-controlled storage.
Mistake 4: Insufficient overlap with the first course. The first course of shingles should overlap the starter strip by at least 4 inches. Anything less creates a weak bond and increases the risk of water penetration.
Mistake 5: Poor fastening or no fastening. The starter strip must be securely nailed before the first course goes on. A loose starter strip will shift during installation, compromising the entire bottom edge.
The Bottom Line: Don’t Let Your Roof Fail at the Foundation
The starter strip is unglamorous. It’s hidden. Most homeowners never think about it. But it’s the foundation of roof performance, and it’s the first line of defense against water damage and wind uplift. A quality starter strip, properly installed, will protect your home for 20+ years. Cut corners here, and you’re betting against your home’s structural integrity.
When you’re getting roof estimates, ask contractors specifically about their starter strip installation process. Ask to see photos of past jobs. Ask whether they use brand-name materials or off-brand alternatives. The answers will tell you a lot about how seriously they take the details that matter.
If you’ve noticed signs of roof damage—missing shingles, granules in your gutters, water stains on your ceiling, or storm damage—don’t wait. We offer a free inspection with no commitment, and we’ll deliver a detailed estimate within 48 hours. We serve both sides of the Mississippi River across Illinois and Missouri, and we’re here to answer your questions honestly.
Schedule your free roof inspection today. We’ll show you exactly what’s happening on your roof and give you a clear path forward.
Get A Free Roof Inspection
