Roofing Nails and Fasteners: Placement, Length, and Wind Resistance

The Asphalt Roofing Manufacturers Association (ARMA) says that for most asphalt shingles, each full-size strip shingle needs at least four nails, placed below the sealant strip but above the part that stays visible, and long enough to reach at least 3/4 inch into the roof deck. Some manufacturers call for six under specific conditions, and the shingle’s own installation instructions decide which pattern applies to your roof.

Where each nail lands matters more than the count in a sales pitch. Six nails in the wrong place can hold worse than four in the right place, and nobody can see the difference once the next course covers them.

Where Each Nail Belongs on a Shingle

Every strip shingle has a nailing zone, a band across the shingle where nails are supposed to go. ARMA’s bulletin on nail application of asphalt shingles puts it this way: “For most shingles with sealant on the top surface, place nails below the sealant strip but above the area that will be visible.” Some manufacturers mark the zone on the shingle itself; Owens Corning’s Duration Series installation instructions state that “fasteners must be placed in the SureNail® Technology fastening area.”

The zone exists because each nail has two jobs. It holds the shingle being installed, and it passes through the top edge of the shingle in the course below, which that course’s own nails do not reach. A nail in the zone pins both. A nail placed above it may hold only one shingle, and a nail placed below it ends up exposed or under the sealant line of the next course.

The zone also keeps nails clear of the sealant strip. The strip is what bonds each course to the one below once the sun warms it, and a nail head sitting in it, or a shingle pushed up by a raised nail, can keep that bond from forming.

Use “nailing zone” when you talk to the roofer, and ask which product and which zone the crew is following.

Nail Length and Type: What Has to Reach the Deck

Length is set by what the nail has to pass through and how far it must reach into the deck, not by the shingle alone. ARMA says to select nails long enough to penetrate at least 3/4 inch (19 mm) into the roof deck. The 2021 Seattle Residential Code, which is Seattle’s locally amended copy of the International Residential Code (IRC), puts similar terms into its roof assemblies chapter: nails “of a length to penetrate through the roofing materials and not less than 3/4 inch (19.1 mm) into the roof sheathing,” or all the way through sheathing thinner than that.

The same code text sets the nail itself: “galvanized steel, stainless steel, aluminum or copper roofing nails,” with a “minimum 12-gage [0.105 inch (3 mm)] shank with a minimum 3/8-inch-diameter (9.5 mm) head, complying with ASTM F1667.” Owens Corning’s Duration instructions ask for galvanized steel, stainless steel or aluminum nails with a minimum 12 gauge shank and 3/8 inch diameter head. Your local code and your shingle’s instructions are the two documents to check. Some local rules also exclude staples outright; the City of Brainerd, Minnesota’s chart of code requirements for roofing materials reads “NO STAPLES” for asphalt shingle fasteners, so check what your jurisdiction allows.

Length needs to grow where layers stack up. Nails through hip and ridge caps, through a ridge vent, through extra layers at valleys and flashing, or through the old shingles on an overlay have more material to pass before they reach the deck. Ask whether the crew changes nail length at those spots.

Two related topics live elsewhere. Salt air changes which fastener metals last, covered in fasteners near salt air. The nails that hold the deck to the rafters are a separate schedule, explained in deck nailing in hurricane zones.

Four Nails or Six: What Each Manufacturer Asks For

“Six nails” is not one rule; different documents attach it to different conditions.

The GAF line is a warranty condition. The GAF Shingle & Accessory Limited Warranty (RESWT160L-0426) ties its higher wind coverage to that installation, and what the coverage means is explained in what the wind class means. The starter requirement in the same condition is covered in starter at eaves and rakes.

Owens Corning’s written six-fastener rule, by contrast, is about slope. Its instructions say: “For slopes exceeding 60 degrees or 21 inches per foot, use 6 fasteners and 4 spots of asphalt roof cement per shingle.” The page also shows a six-fastener pattern, but it does not tie six fasteners to wind.

So when a roofer says “we use six nails,” the useful follow-up is which document that serves: a steep-slope instruction, a warranty condition, or a local code amendment.

High, Overdriven, and Crooked Nails: How Bad Nailing Fails in Wind

High nails sit above the nailing zone. Because they may miss the top edge of the shingle below, that lower shingle loses some of its anchoring, and a gust that lifts its tab can pull it loose or let it slide out from under its neighbors. High nailing is hard to spot afterward, because the shingle looks normal until wind tests it.

Overdriven nails are driven so hard that the head cuts into the shingle mat. The head then holds less material, and wind lifting the shingle can pull the shingle over the nail head. Underdriven nails leave the head standing proud, which can keep the next course from lying flat and sealing, and can wear through the shingle above.

Crooked nails, driven at an angle, combine both faults: one side of the head cuts in while the other side stands up.

After a wind event, nailing faults can leave clues. Shingles that came off while their neighbors held, or loss concentrated along particular courses, can point to placement problems, and a roofer can lift an intact shingle beside the damage to see where its nails sit. The guide to lifted and creased shingles covers how to read storm damage.

Who Checks the Nailing, and When

Do not assume anyone checks the nailing after the fact unless you arrange it. The InterNACHI home inspection Standards of Practice let an inspector work “from ground level or the eaves” and state that the inspector is not required to “confirm proper fastening or installation of any roof-covering material.” A home inspection under that standard, in other words, is not required to verify nail placement.

Whether a building inspector looks at nailing during a re-roof varies by jurisdiction; ask your building department what its re-roof inspection covers.

The practical check is photo proof during the job. Ask the crew to photograph nailed courses before the next course covers them, at an eave, in the middle of a slope and near the ridge. In each photo you should see nails in the marked zone, heads flush with the shingle surface, and the count your contract names.

Checking after the roof is finished means lifting sealed shingles, which can break the bond and should be done only by a roofer with a reason.

Is Your Roofer’s Nailing Plan Good Enough to Sign?

Sign when the contract names the shingle product, the nails per shingle that the maker’s instructions and your chosen warranty require for your slope, the nail type and length, and photo documentation of nailed courses. If the plan says “six nails” without saying why, ask which instruction, warranty condition or code amendment it serves before you accept it as an upgrade.

Read the shingle maker’s installation instructions for count and zone first, then ask in writing which pattern the roofer will use and whether it meets the warranty’s installation terms, and request photos of nailed courses before they are covered. The roof components reference defines the deck, courses and other terms used in those instructions.

This guide is general information for U.S. homeowners, not legal, insurance, tax, or engineering advice. Codes, laws, and policy terms vary by location and change over time; confirm details with your local building department, your insurer, or a licensed professional.

Sources

• Nail Application of Asphalt Shingles, Asphalt Roofing Manufacturers Association (ARMA)
• Duration Series Shingles Installation Instructions, Owens Corning
• 2021 Seattle Residential Code, Chapter 9: Roof Assemblies, City of Seattle, Seattle Department of Construction and Inspections (SDCI)
• GAF Shingle & Accessory Limited Warranty (RESWT160L-0426), GAF
• Code Requirements for Various Roofing Materials (RV1.21), City of Brainerd, Minnesota
• InterNACHI Home Inspection Standards of Practice (Section 3.1 Roof), International Association of Certified Home Inspectors (InterNACHI)