What is a starter strip on a roof?
Last updated · Roof anatomy
Short answer: A starter strip is a row of shingle material installed along the eaves, and often the rakes, before the first full course of shingles. It fills the gaps between the first course's tabs and puts a line of sealant at the roof edge so the first row bonds down. Without it, edge shingles leak and lift in wind.[1]
What does a starter strip do?
A starter strip does two jobs. First, it provides a solid layer under the cutouts and joints of the first visible course, so water that runs through a gap lands on shingle material instead of on underlayment. Second, the factory sealant on most starter products sits right at the roof edge, where it bonds to the underside of the first course. That bond is what keeps the edge from peeling back in a windstorm.
What is a starter strip made of?
Most manufacturers sell dedicated starter shingles: narrow strips with sealant positioned along the edge. Some crews still make starters by cutting the tabs off 3-tab shingles and turning them so the sealant is near the eave. Laminated shingles are not suitable for this, because their sealant line and thickness are not designed for it. Asphalt roofing manufacturers publish application guidance for starter courses, and shingle warranties often require the maker's own starter product.[3]
Where does a starter strip go?
The starter course runs along the full length of every eave, overhanging the drip edge slightly so water drips clear. Many manufacturers also call for a starter course up each rake edge, which gives rake shingles a sealant bond too. The code requires drip edge at both eaves and rakes, with the underlayment over the drip edge at eaves and under it at rakes, and the starter goes on top of that assembly.[1]
Why does the starter strip matter in high winds?
Wind-resistance ratings for shingles, such as those determined under ASTM D3161, are based on test panels installed with the manufacturer's specified details.[2] In real storms, failures often start at the eaves and rakes, where air can get under the first course. A missing starter, or one installed with the sealant at the wrong edge, leaves the first course unsealed. Once the wind lifts that course, it can peel the courses above.
What installation mistakes should you watch for?
Watch for a few common starter strip mistakes: - Starter installed with the sealant strip up the roof instead of at the eave. - Starter joints aligned with the joints of the first course, so water runs straight through. - No starter on the rakes when the manufacturer requires one. - Starter set back from the drip edge, leaving the edge unsealed. - Nails placed too low, where they will show or let water in.
Does a missing starter strip void a shingle warranty?
It can. Shingle makers condition their limited warranties, and especially enhanced wind coverage, on installation per their written instructions. If a wind claim reaches the manufacturer and the inspector finds no starter course, coverage for that failure may be refused. Keep your contractor's material invoice and photos showing the starter, and register the warranty if the maker requires it.
What should you ask a roofer about starter strips?
Ask your roofer which starter strip product they will use, whether it goes on both eaves and rakes, and whether it matches the manufacturer's system requirements for the warranty you are being sold. Ask for a photo of the eave before the first course goes on. These are cheap details, and a contractor who skips them to save a few bundles is cutting a corner you will not see until a storm.
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Frequently asked questions
Can I see the starter strip after the roof is done?
Not usually. It sits under the first course. Photos during installation are the best proof it was installed.
Is a starter strip required by code?
The code requires installation per the manufacturer's instructions, and most manufacturers require a starter course at the eaves.
Do metal roofs use starter strips?
Not the shingle kind. Metal panels use eave trim and closures specified by the panel maker.
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Sources
- 2021 International Residential Code, Chapter 9: Roof Assemblies. codes.iccsafe.org/content/IRC2021P2/chapter-9-roof-assemblies
- ASTM D3161: Wind Resistance of Asphalt Shingles (Fan-Induced Method). store.astm.org/d3161_d3161m-20.html
- Asphalt Roofing Manufacturers Association. www.asphaltroofing.org/
Sources checked November 4, 2026. Estimates are not quotes. Roofing, insurance, and legal details vary. Confirm with your contractor, insurer, or attorney.