Nail pattern

More roofing & materials terms

• Metal roof

  A roofing system of metal panels or shingles (steel, aluminum, copper). It has a long life, is often a code or coverage consideration, and is priced differently from asphalt shingles.

• Modified bitumen

  A roofing membrane made of asphalt reinforced with a polymer, sold in rolls and applied with heat, adhesive, or peel-and-stick backing, most often on low-slope roofs. It is priced by the square in Xactimate, and the application method and number of plies are separate line items.

• Nail pop

  A fastener that has backed out and is lifting the surface above it - a shingle on a roof, or the painted surface of drywall inside - usually from movement, heat cycling, or a fastener that missed the framing. A few are a repair; pops across a whole slope usually point to an installation or ventilation problem rather than to wind or hail, and that pattern is often not covered as storm damage.

• OSB

  Oriented strand board - an engineered panel of glued wood strands, commonly used as roof decking instead of plywood. It is easy to spot by the flake pattern; it holds fasteners well while dry, but once it gets wet it swells at the edges and loses that grip, so it draws close attention on water and storm claims.

• Parapet wall

  The low wall that extends above the roofline at the edge of a flat or low-slope roof, often on commercial buildings and sometimes on homes. It gets its own flashing, coping, and sealant line items, and those details are commonly missed when a scope is written from photos.

• Peel-and-stick membrane

  A self-adhering roofing membrane, often used as underlayment on steep-slope roofs or as a cap sheet on low-slope roofs, that seals around nails and resists ice dams. It is priced by the square, and where it is required depends on the local code.

Common questions