Roof Terms & Definitions
If you’ve had a recent roof repair or replacement or you’ve recently met with a professional roofing company to install a new roof, you may have heard some terms you’re unfamiliar with. We’ve compiled a list of common roof terms and definitions so you won’t be confused when your roofing contractor discusses your roofing issues with you in the future.
Common roof terms you might hear include:
Aggregate – Stone, rock, water-worn gravel or slag (in a range of different sizes) used for UV protection; granule is an example
Apron flashing – flashing at the juncture of the top of a sloped roof and a vertical wall
Area Divider – raised, flashed assembly that extends above the roof’s surface when an expansion joint isn’t required or to separate large roof areas
Back surfacing – mineral matter that is applied to the back of shingles so they don’t stick
Ballast – different materials used to protect roofing from UV rays (see aggregate)
Base flashing – part of the flashing attached to (or resting on) the deck, which is used to direct the flow of water onto the roof covering
Blister – bubble that sometimes appears on the roof’s surface after installation or is caused by expansion of trapped air or water
Built-up roof (BUR) – flat roofing or low-sloped roofing that has multiple layers of asphalt and ply sheets
Cap sheet – granulated surface used as the top ply of a BUR; when used, aggregate isn’t required
Caulk – mastic or asphalt cement used to fill prevent small leaks in the flashing
Cladding – material used for the exterior wall of a building
Cornice – the top set of moldings below the roofline
Coverage – the amount of weather protection provided by your roofing material
Counterflashing – usually metal sheeting attached to a pipe, rooftop unit or other surface to protect the upper edge of the base flashing
Deck – surface (typically plywood) where materials are applied
Dormer – a structural element protruding from the surface of a sloped roof, creating more usable space inside the building or house
Dormer rafter – roof rafters that frame the dormer roof
Downspout – vertical pipe that carries water from the gutter to the ground
Drip edge – overhang (usually metal flashing) used to direct dripping water away from the rest of the underlying roofing structure
Eave – lower edge of a sloped roof that extends down past the wall
Eave vent – opening along the edge of the roof used to dissipate heat and moisture
Fascia – a flat board at the cornice’s outer edge, running along the eaves of the roof
Flashing – elements used to weatherproof or seal roof edges at perimeters, walls, expansion joints, drains and other areas where roofing material ends
Gable – section of a sidewall that forms a triangle at the ridge of a sloped roof
Interlocking shingles – individual shingles that attach to each other and don’t require sealing strips, used to provide extra wind resistance
Laminate – process of joining layers together using some type of adhesive (like mastic)
Rafter – a component designed to support the deck and roofing system, usually installed from the highest point (ridge) to the eave
Rake – inclined edge of a roof over a wall
Soffit – finished underside of the eaves
Truss – triangular structure used for support; multiple trusses are used to assemble the roof’s framework
Vent – a pipe or stack that protrudes through the roof deck to ventilate the underside of the deck
For any other questions about roof terms and definitions or if you need any roofing services in the Maryland, Washington, DC and Virginia area, contact Shanco today!
