Roofing Terms Defined
Roofing terms defined G - M
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Gable: The upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.
Gable roof: A type of roof containing sloping planes of the same pitch on each side of the ridge. A gable roof typically contains a gable at each end.
Gambrel roof: A type of roof containing two sloping planes of different pitch on each side of the ridge. The lower plane has a steeper slope than the upper. A gambrel roof usually contains a gable at each end, just like a standard gable roof.
Granules: Ceramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
Gutter: The trough that channels water from the eaves to the downspouts.
HEX shingles: Shingles that have the appearance of a hexagon after installation.
Hip: The inclined external angle formed by the intersection of two sloping roof planes. The hip runs from the ridge to the eaves.
Hip roof: A type of roof containing sloping planes of the same pitch on each of four sides. A hip roof contains no gables.
Hip shingles: Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
Ice dam: Ice dams occur when snow melts near the ridgelines of warm roofs (roofs without adequate ventilation). As the water runs down the roof to the overhang, it cools and freezes. If the snow continues this melt and freeze process, an ice dam can form that can seep under the shingles, through the decking and into the house. This, of course, can cause serious roof leaks--even in freezing temperatures.
The best prevention to ice dams is a well-ventilated (cool) roof. Additional protection for your roof can be applied with an impermeable ice and water membrane. The membrane is installed on top of the decking, under the roofing material. Temporary prevention of ice dams can also be done through the use of electric cables along the eaves of the roof (where the dams usually form). However, new ice dams can form above the cables and still cause extensive damage. Another emergency solution to ice dams is to fill a sock or nylon with calcium chloride. Lay the stocking vertically across the ice dam. The calcium chloride will melt the ice and release the water so that it can drain outside, and not inside your roof.
Intake Ventilation: The part of a ventilation system used to draw fresh air in. Usually vents installed in the soffit or along the eaves of a building.
Interlocking shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.
Joists: Any of the small timbers or metal beams ranged parallel from wall to wall in a structure to support a floor or ceiling.
Laminated shingles: Strip shingles containing more than one layer of tabs to create extra thickness. Laminated shingles are also called three-dimensional shingles.
Lap: To cover the surface of one shingle or roll with another.
Lap cement: An asphalt-based cement used to adhere overlapping plies of roll roofing.
Lean-to roof: A roof with one slope only that is built against a higher wall.
Life-cycle cost: The total lifetime cost of a roof. Calculated by adding maintenance costs to the installed price, then deducting the added value the roof provides when the home is resold.
Low slope application: Method of installing asphalt shingles on roof slopes between two and four inches per foot.
Mansard roof: A type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Contains no gables.
Mastic: An asphalt-based cement used to bond roofing materials. Also known as flashing cement.
Metal drip edge: A narrow strip of non-corrodible metal used at the rake and eave to facilitate water runoff.
Mineral-surfaced roofing: Asphalt shingles and roll roofing that are covered with granules.
Modified Bitumen: Roofing asphalt that has been blended with some of a broad range of materials which improve its performance characteristics.