Proper Nail Application For Asphalt ShinglesOliver Olinger, Writer
Required by the International Building Code, proper nailing is essential to the optimum performance of roofing shingles. Accurate nailing requires the use of approved nails, nail-driving methods and placement (depending heavily on which shingle type is being employed).
Atlas has installation guidelines in place to ensure proper, uniform installation of Atlas shingles on every roof, whether that roof is new or recovered. Nails should have a minimum, nominal shank diameter of 11- or 12-gauge, and a minimum head diameter of three-eighths of an inch. The length of each nail must be a minimum of 1¼ inches long, and for roof-overs, Atlas recommends a nail length of at least 2 inches.
Nails of the proper length should penetrate three-fourths of an inch into the roof deck. However, where the roof deck is less than three-fourths of an inch thick, the nail should be long enough to penetrate fully and extend at least one-eighth of an inch through the roof deck.
Each shingle model has specific requirements for nails printed on each shingle wrapper. These guidelines must be followed to comply with building codes and ensure intended performance levels
All nails need to be driven either by hand (with the use of a hammer) or with a properly adjusted pneumatic nailer. Improper adjustment of a pneumatic nailer can result in overdriven or underdriven nails, which can cause nail corrosion, sealing failures, raised tabs, buckling and blow offs.
A nail that is incorrectly driven into a shingle needs to be repaired immediately. Underdriven nails can be tapped down until they are snug against the shingle. However, overdriven and crooked nails need to be removed at once. Repair the resulting hole with asphalt roof cement (ASTM D4586 compliant) and place another nail nearby (but not in the same spot). If this technique isn’t possible, replace the entire shingle.
The placement of nails is of the utmost importance when installing a new or recovered roof. Nails must never be placed where they will be visibly exposed or weathered.
Always place nails no closer than 1 inch from the edge of a shingle, and always check for specific nail positioning requirements on the installation instructions for each shingle type.
Be wary not to drive nails into knotholes, cracks or spaces in the roof deck. Do not overdrive or underdrive nails. Each nail head should bear tightly against the face of the shingle without breaking or cutting into the shingle itself.
Remember, the reason that nail application on Atlas shingles is so important is to ensure maximum performance of each roof. If proper attention is not paid to nail type, placement and procedures, the shingles may fail as a result of raised tabs, buckling or improper sealing. Be sure to follow all local building codes.
For more information about proper nail placement, visit atlasroofing.com/roof-shingles.