A Concrete Tile Nailing Guide

Regulations

• Though local and state building authorities vary their buildings regulations to meet the needs of their constituents, they base their guidelines on the International Residential Code, or IRC. The International Code Council maintains this code, as well as others that can affect roofing construction such as the International Fire Code, the International Building Code and the International Energy Conservation Code. Founded in 1994, this nonprofit organization streamlined regulations and eliminated duplication among three competing national codes. Its goal is to help “the building safety community and construction industry provide safe, sustainable and affordable construction.”

Nails

• The IRC mandates that the nails used with concrete tile must be corrosion resistant and be at least 11 gage or have a head that is at least 0.31 inches in diameter. It must be long enough to penetrate the roofing deck through the entire thickness or by a minimum of 0.75 inches, whichever is less. The attachment wire must be at least 0.083 inches in diameter. The tile must be fastened by at least three tile courses at the perimeter, but not less than 3 feet from the sides of hips or ridges, or the edges of eaves and gables.

Applications

• Roofers must follow both the manufacturer’s installation instructions and the IRC based on local climate conditions, roof slope and underlayment. Perimeter tiles need at least one nail per tile. If the tile weighs at least 9 pounds per square foot, each tile needs one nail regardless of roof slope. If the sheathing is spaced or solid with battens, and the slope rises less than 5:12 (five units for every 12 of horizontal movement), fasteners are not required. If the sheathing is spaced without battens, and the slope is between 5:12 and 12:12, one nail is needed per tile every other row. If the slope is between 12:12 and 24:12 for the same sheathing, each tile needs a nail.

Weather

• Roofers must apply tile according to manufacturer’s guidelines, instead of to IRC code, in areas where wind speed goes over 100 mph, or in buildings where the roof is over 40 feet above ground level. In areas subject to snow, each tile requires at least two nails. In areas with winds above 110 mph, the underlayment under concrete tile must also be fastened with corrosion-resistant fasteners, applied on the overlap no farther apart than 36 inches on center.