Modified bitumen

More roofing & materials terms

• Ice and water barrier

  A self-adhering membrane installed in eaves, valleys, and around penetrations to stop leaks from ice dams and wind-driven rain.

• 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.

• Nail pattern

  The spacing and placement of nails that fasten shingles or sheathing, set by the shingle manufacturer and the local code. It is checked during roof inspections, and an improper pattern is a common reason a carrier denies or prorates a shingle repair.

• 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.

Common questions