What are architectural roofing shingles, and how are they installed?
Short answer. Architectural roofing shingles are asphalt shingles made of two layers laminated together, which gives them a thicker, dimensional look and better wind resistance than flat 3-tab shingles. They are installed over a starter strip in offset courses, nailed through the double-thick zone where the two layers overlap.
How they are built
A full-width base layer is bonded to a top layer cut into tabs of varying widths. Where the two layers overlap is the common bond, and that is where the nails belong. The random tab pattern hides minor deck waves and makes the roof look textured from the street. Under the granules is a fiberglass mat coated with asphalt, the same core as a 3-tab shingle but thicker.
How a crew installs them
- Prep. Old roof off, deck inspected and bad sheets replaced, then drip edge, underlayment and membrane at valleys and penetrations.
- Starter strip. A starter course with its own sealant runs along the eaves and usually the rakes, so the first course is glued down.
- Field courses. Shingles go on in rows with the manufacturer's offset so seams never line up. Each gets four nails, or six where the maker calls for it, through the marked nailing zone.
- Flashing. Step flashing at walls, new pipe boots, and chimney and valley details.
- Hips and ridge. Matching ridge cap shingles, often over a ridge vent.
Why the details matter
A nail placed above the common bond catches only the top layer, and that is how architectural shingles peel off in strong Georgia storms. Using the maker's own starter, ridge cap and underlayment can also extend the warranty coverage. For a side by side comparison, see architectural vs 3-tab shingles, and for the day itself, what to expect on roof replacement day.