Glossary

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Vacuum Breaker: An anti-siphon device designed to prevents waste water from flowing back into supply lines, potentially contaminating the water supply.

Valley: A depression or angle formed by the meeting of two inclined sides of a roof.

Valley Rafter: The place of meeting of two slopes of a roof, which have their plates running in different directions, and form on the plan a re["e]ntrant angle. (b) The depression formed by the meeting of two slopes on a flat roof.

Valley Shield: Additional protection against the heavy water flow areas of a roof.

Valuation: The act of estimating or setting the value of something; appraisal.

Valuation Fee: The cost of estimating the value of something.

Valve: Any device for halting or controlling the flow of a liquid, gas, or other material through a passage, pipe, inlet, outlet, etc.

Vapor: A visible exhalation, as fog, mist, steam, smoke, or noxious gas, diffused through or suspended in the air.

Vapor Barrier: A layer of material, as plastic film or foil, used to protect installed insulation by retarding the transmission of moisture from the interior environment.

Vapor Retarder: Any substance that prevents or limits the transmission of water vapor.

Variable Rate: Providing for changes in the interest rate, adjusted periodically in accordance with prevailing market conditions.

Varnish: A coating designed to create a glossy appearance.

Vehicle: A means of transmission or passage.

Veining: A long wavy strip of a different shade or color, as in wood or marble, or as mold in cheese.

Veneer: Any material which supplies a superficial value or pleasing appearance.

Vent: An opening, as in a wall, serving as an outlet for air, smoke, fumes, or the like.

Vent Pipe: A pipe above a waste pipe or soil pipe that allows gas to escape from the system.

Vent Stack: A vertical pipe that provides circulation of air to and from any part of a drainage system.

Vent System: Any system that provides circulation of air within such system to protect traps seals from back pressure.

Ventilator: A device that circulates fresh air and expels stale or foul air.

Venting: A means of escape or release from confinement; an outlet.

Vermiculite: Any of a group of platy minerals, hydrous silicates of aluminum, magnesium, and iron, that expand markedly on being heated: used in the expanded state for heat insulation and as a plant growth medium.

Vertical: Being in a position or direction perpendicular to the plane of the horizon; upright; plumb.

Veterans Administration (VA): A federal agency that insures mortgage loans for honorably discharged veterans and their surviving spouses.

Viscosity: The property of a fluid that resists the force tending to cause the fluid to flow.

Visible Light Transmittance: The portion of visible light (390 to 770 nanometers) within the solar spectrum transmitted through glass.

Visqueen: A type of polyethylene sheet used to cover areas in building construction and in making waterproof items

Visual Mock-Up: A small scale model of a finished product.

Vitreous China: A non-porous ceramic coated with a ceramic glaze.

Void: Without contents; empty.

Volatile Thinner: A liquid that evaporates quickly and is used to reduce the consistency of finishes without altering the relative volumes of pigment and non-volatile vehicles.

Voltage: The rate at which energy is drawn from a source that produces a flow of electricity in a circuit; expressed in volts.

Voltmeter: An instrument for measuring in volts the differences of potential between different points of an electrical circuit.