G
GABLE- The end of a building as distinguished from the front or rear side. The triangular end of and exterior wall from the level of the eaves to the ridge of a double-sloped roof.

GABLE ROOF- A roof configuration that has gable ends.

GAMBREL ROOF- A type of roof which has its slope broken by an obtuse angle, so that the lower slope is steeper than the upper slope. A double sloped roof having two pitches.

GALVANIC ACTION- A reaction between different metals in the presence of an electrolyte.

GALVANIZE- To coat a metal with zinc by dipping in molten zinc after cleaning.

GAUGE- The thickness of sheet metal and wire, etc.

GLASS FELT- In the manufacturing of roofing materials - a sheet comprised of bonded glass fibers prior to being saturated with bitumen.

GLAZE COAT- A light, uniform mopping of bitumen on exposed felts to protect them from the weather, pending completion of the job.

GRANULES- Mineral particles of a graded size which are embedded in the asphalt coating of shingles and roofing.

GRAVEL- Loose fragments of rock used for surfacing built-up roofs, in sizes varying from 1/8" to 1 3/4".

GRAVEL STOP- A flanged, sheet metal edge flashing with an upward projection installed along the perimeter of a roof to stop the flow of bitumen over the edge.

GROUT- A cement mortar mixture commonly used to fill joints and cavities of masonry. On roof decks, the joints between many types of precast roof deck slabs are grouted with cement grout.

GUTTER- Metal trough at the eaves of a roof to carry rainwater from the roof to the downspout.

GUTTER STRAP- Metal bands used to support the gutter.

GUY WIRE- A strong steel wire or cable strung from an anchor on the roof to any tall slender projection for the purpose of support.

GYPSUM- A hydrated sulfate of calcium occurring naturally in sedimentary rock. In roofing, a type of lightweight deck made from this pulverized rock.

H
HATCH- An opening in a deck; floor or roof. The usual purpose is to provide access from inside the building.

HEAT SEAMING- Fusing the seams of separate sections of roofing material together through the use of hot air or an open flame and pressure.

HEAT TRANSFER- Thermal energy going from an area of higher temperature to an area of lower temperature by conduction, convection, or radiation.

HEM- The edge created by folding metal back on itself. Metal is hemmed for safety and strength reasons.

HEX SHINGLES- Shingles that have the appearance of a hexagon after installation.

HIP- The angle formed by the intersection of two sloping roof planes.

HIP ROOF- A roof which rises by inclining planes from all four sides.

HIGH NAILING- When shingles are nailed or fastened above the
manufacturer's specified nail location.

"HOT"- Slang for hot bitumen.

I
ICE DAM- Ice formed at the transition from a warm surface to a cold surface, such as along the overhang of a house. The build-up of ice is the result of ice or snow melting on the roof area over the warmer, living area of a building and then refreezing when it runs down and reaches the overhang.

ICE AND WATER SHIELD (Leak Guard)- Composite materials of asphalt polymers in a self-adhered roll used in roofing as underlayment to prevent problems associated with ice-dams and high water flow areas.

IMPACT RESISTANCE- A roof assembly's ability to withstand the impact from falling objects such as hail.

INFRARED THERMOGRAPHY- The use of an infrared camera to detect moisture in roof insulation.

INCOMPATIBILITY- Descriptive of two or more materials which are not suitable to be used together.

INSIDE DRAIN- A roof drain positioned on a roof at some location other than the perimeter. It drains surface water inside the building through closed pipes to a drainage system.

INSULATION- Material which slows down or retards the flow or transfer of heat.

INSULATION FASTENERS- Any of several specialized mechanical fasteners designed to hold insulation down to a steel or a nailable deck.

INSULATION VENT- A vent placed into the insulation which extends above the roof surface.

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.

INTERLAYMENT- A waterproof material usually installed between adjacent rows of wood shakes to help with the roof's waterproofing characteristics.

INTERLOCKING SHINGLES- Shingles that lock together to provide wind resistance. See also T-Lock.

IRMA- Insulated (or Inverted) Roof Membrane Assembly. In this system the roof membrane is laid directly on the roof deck, covered with extruded foam insulation and ballasted with stone, minimum of 1000 lbs. per square.