How do you start architectural shingles?
Short answer. Architectural shingles start with a starter strip along the eave, and usually the rakes, installed with its sealant line at the roof edge, followed by a first course of full shingles laid flush with the starter's bottom edge. Snap chalk lines first, set the overhang past the drip edge within the manufacturer's range, and begin the offset pattern the wrapper shows.
Why the starter strip matters
The first course of shingles has nothing underneath it to seal to. A starter strip fills that gap: it puts a line of sealant right at the roof edge so the first course bonds down, and it covers the joints between first-course shingles so water cannot drop straight through to the underlayment. Wind uplift starts at the edges, so this is where many blow-offs begin when the starter is skipped or installed wrong.
Step by step
- Check the edge details: eave drip edge under the underlayment, rake drip edge over it.
- Snap a line for the starter so it overhangs the drip edge evenly. Most manufacturers call for roughly 1/4 to 3/4 inch, and some use a narrower range, so read the wrapper.
- Install the starter along the eaves with the sealant strip at the bottom edge, nailed in the zone the product marks. Run starter up the rakes too if the manufacturer calls for it.
- Snap course lines up the roof at the shingle's exposure, often 5 5/8 inches for common architectural shingles, so every course stays straight.
- Lay the first course of full shingles with the bottom edge flush with the starter, offsetting the joints from the starter joints.
- Start the offset pattern: the second course begins with a shingle cut by the amount the manufacturer shows, and the pattern continues up the roof.
Mistakes to avoid
- Using upside-down shingles as starter, which puts the sealant in the wrong place.
- Too much overhang, which lets edges sag and break.
- Lining up starter joints with first-course joints.
See drip edge explained and wind damage to roofs in Georgia.