Asphalt shingles are the most common residential roofing material in the United States by a wide margin. That widespread use has created a large and varied pool of shingle roofers — ranging from highly skilled, manufacturer-credentialed professionals to underprepared contractors who install shingles incorrectly and move on before the consequences show up.
Because the finished product looks essentially the same from the street regardless of installation quality, homeowners often can’t tell who did good work until months or years later — when a section of shingles lifts in a windstorm, granule loss accelerates ahead of schedule, or a leak develops at a flashing seam that was never properly sealed.
Understanding what distinguishes expert shingle roofers from average ones — before you hire — protects your investment and your home.
How Asphalt Shingles Actually Work
Before evaluating shingle roofers, it helps to understand what’s actually happening in a shingle installation. Asphalt shingles are a layered weather-protection system, not a single material slapped onto a deck.
A properly installed shingle system includes:
Roof deck (sheathing). Typically plywood or OSB. The deck must be sound — no soft spots, delamination, or rot — before any other component is installed. Shingle roofers who skip a thorough deck inspection before laying new material are building on a compromised foundation.
Drip edge. Metal flashing installed at eaves and rakes before underlayment. Drip edge directs water off the roof edge cleanly and prevents water wicking back under the shingles. It is required by most building codes and manufacturer installation specifications. Shingle roofers who skip drip edge are cutting a corner that violates code and voids most manufacturer warranties.
Underlayment. A protective membrane layer installed over the deck and beneath the shingles. Synthetic underlayment has largely replaced traditional felt in quality installations — it’s lighter, more tear-resistant, and provides better weather protection during installation. In areas prone to ice dams (including western NC mountain markets), a self-adhering ice and water shield is required at eaves and vulnerable areas.
Shingles. Installed from the bottom of the roof upward, with each course overlapping the one below. The exposure (the portion of the shingle visible from below) must be consistent and within manufacturer specifications. Fastener placement — nail location and depth — is among the most consequential installation variables. Nails placed too high (a “high nail” error) leave the shingle improperly secured and dramatically reduce wind resistance.
Flashing. Metal components installed at all penetrations, valleys, and transitions. Flashing is where most shingle roof leaks originate. The skill with which flashing is fabricated and installed is one of the clearest markers of roofer quality.
Ridge cap. Shingles or pre-formed ridge cap product installed at the peak. Ridge caps must be fastened with the appropriate nail length to penetrate through the cap and into the deck — a common error is using standard shingle nails that don’t reach the deck through the additional ridge cap material.
What the Best Shingle Roofers Do Differently: 5 Proven Differences
The difference between a professional shingle installation and a mediocre one comes down to a handful of practices that matter enormously for long-term performance.
Deck Inspection and Preparation
Expert shingle roofers inspect the deck before they install a single shingle. They walk it, probe soft spots, and replace compromised sheathing before proceeding. They don’t quote a price and then present an unexpected bill for deck issues discovered during tear-off without prior communication — they establish a clear per-sheet rate upfront so there are no surprises.
Proper Fastener Placement
Industry and manufacturer specifications require fasteners to be placed in the nailing strip — a defined zone on each shingle course. Nails placed too high, too low, or driven at an angle don’t hold properly and create wind vulnerability. Expert shingle roofers have crew that nail consistently and supervisors who check.
Pneumatic nail guns, which most crews use for speed, must be properly calibrated for shingle installation. A nailer set too high drives nails through the shingle. One set too low leaves them proud of the surface. Neither holds correctly. Crews that don’t calibrate their tools regularly — or don’t have supervisors who check — produce installation defects that aren’t visible until they become problems.
Flashing Quality
A roofer who uses cheap step flashing, applies inadequate sealant, and moves quickly through chimney and valley details is producing a roof that will leak. Expert shingle roofers spend appropriate time at every penetration and transition, use quality flashing materials (heavier gauge metal, self-adhering membrane behind step flashing), and understand that flashing is where warranties get tested.
Starter Course Installation
The starter course — a modified first row of shingles or a dedicated starter strip product — establishes the foundation for every course above it. It must be installed with proper overhang, proper adhesion at the eave, and alignment that allows the first full shingle course to be properly positioned. Rushed or imprecise starter installation compounds through every course above it.
Consistent Exposure and Alignment
Shingle courses must maintain consistent exposure (the visible height of each shingle row) and remain aligned across the full width of the roof. Expert shingle roofers snap chalk lines and check alignment regularly during installation. Crews in a hurry cut these steps and produce wavy or irregular coursing that is visible from the street on close inspection.
Manufacturer Credentials as a Quality Proxy
The best shingle roofers typically hold manufacturer credentials that reflect their installation quality and training commitment.
GAF Master Elite: Less than 2% of roofing contractors in North America hold this designation. Earning it requires verified licensing, insurance, training completion, and sustained customer satisfaction. Master Elite contractors can offer GAF’s strongest warranty products, including the Golden Pledge 25-year material and labor warranty.
Owens Corning Platinum Preferred: Similar in concept to GAF Master Elite, with training and customer satisfaction requirements that go beyond base licensing. Platinum Preferred contractors offer extended System Protection Limited Warranties unavailable through uncredentialed installers.
CertainTeed SELECT ShingleMaster: CertainTeed’s highest contractor designation, required to offer SureStart PLUS extended warranties. Involves examination-based certification on CertainTeed installation specifications.
These credentials are maintained — contractors who fall below standards lose them. They provide a meaningful independent verification of quality commitment that references and Google reviews alone cannot fully replace.
What to Ask Shingle Roofers Before Hiring
Use these questions to separate expert shingle roofers from contractors who will produce an average result.
What underlayment will you use, and why? A specific answer with a product name and reasoning is good. “Felt paper” or “standard stuff” is not.
How will you handle high nailing or off-spec fastener placement in the field? They should have a quality control process. Vague answers suggest they don’t.
What step flashing detail will you use at this chimney? Pull up a photo of your chimney and ask specifically. A roofer who can describe the detail fluently — step flashing, counter flashing, saddle behind a wide chimney — knows what they’re doing.
What happens if you find rot or soft spots in the deck? There should be a defined price per sheet and a communication commitment before they proceed with additional work.
What is your labor warranty? The minimum acceptable answer is two years. Better contractors offer five or ten.
Red Flags in Shingle Roofer Proposals
No drip edge in the scope. This is a code requirement in most jurisdictions and a manufacturer installation requirement for almost all shingle products. A proposal that doesn’t include drip edge replacement is either cutting a corner or bidding an incomplete scope.
No underlayment upgrade. Any roof replacement should include new underlayment. A proposal that leaves existing felt paper beneath new shingles is not a professional proposal.
Immediate discounts for signing today. Professional roofing businesses price competitively based on materials and labor costs, not sales pressure. Time-limited discounts are a manipulation tactic.
No manufacturer warranty mentioned. Every reputable shingle product comes with a manufacturer warranty. If your contractor isn’t mentioning it, ask why.
Related Reading: How to Choose the Right Roofing Contractor | Shingle Options for Your HomeExternal Resource:GAF Roofing — Understanding Shingle Warranties