Ontario's Premier Fabricator
and Installer of Metal Roofing

General Roofing Terminology

Beam: A long piece of wood or steel that supports your roof that, when grouped, can form a truss.

Cornice: The overhanging part of the roof that sticks out past your walls.

Coverage: The degree of weather protection offered by a roofing material: single, double or triple coverage.

Decking/Sheathing: Normally plywood which provides a flat surface covering your home.

Dormer: A gabled extension protruding from a sloping roof to allow for a framed window.

Drainage: Shape, layout and slope of roof for the purpose of shedding snow and water.

Drip Edge: Weather-resistant metal or vinyl edge installed along eaves and rakes to facilitate shedding of water at the edges.

Eaves: Parts of a roof that project beyond or overhang the face of the wall at the lower edge of the roof.

Eaves Trough: They are also known as gutters. They provide a method by which water that drips off the roof is caught and carried down the down spouts to an appropriate area for it to wash away.

Exposure: Specifically, exposure to weather: the distance from the butt edge of one shingle to another.

Fascia: The vertical edge of the cornice.

Felt: A breather-type building paper of strong, tough base saturated with asphalt.

Flashing: Materials used to prevent leaking/seepage at certain vulnerable spots like valleys, end-walls and chimneys.

Gable: The end wall of a building which comes to a triangular point under a sloping roof; also, a type of roof.

Hip: An external angle formed by the meeting of two sloping ends of the roof, from the ridge to the eaves; also, a type of roof.

Rafters/Trusses: A framework of beams, usually grouped in a triangular nature, that support the roof.

Rake: The inclined edge of a pitched roof over an end wall.

Ridge: The apex of the angle formed by a roof, or the peak, where the common rafters meet.

Roof Covering: most common are asphalt shingles, wood shakes, metal, tile or slate.

Sofit: The horizontal bottom of the cornice.

Square: The amount of roofing material required to cover 100 square feet (10’x10′) of roof surface.

Underlayment: a layer of moisture protection between the decking and exterior roof covering. In northern climates an ice and water shield helps to minimize ice damage problems.

Valley: An internal angle or water runway formed by the intersection of two slopes in a roof.

Venting: Proper venting is necessary for maintaining air-flow and overall roof “health.”