| Term | Definition |
| V | A symbol for vertical shear. |
| V Beam Roof | A roof with corrugated sheeting with flat, V-angled surfaces. |
| V-Belt | Type of belt commonly used in refrigeration work; it has a contact surface with the pulley which is in the shape of the letter V. |
| VA | Veterans Administration. |
| Vacations | The uncoated portion of a finished object; also called Skips and Holidays. |
| Vacuum | 1. A space absolutely devoid of matter. 2. Pressure lower than atmospheric pressure. |
| Vacuum Breaker | 1. An electrical breaker with a space that contains reduced air pressure. 2. A device which prevents the formation of a vacuum in a water supply pipe; installed to prevent backflow. |
| Vacuum Cleaner | One of several types of suction devices used to collect dirt from the bottom of a swimming pool; these units work in a variety of ways - some force collected dirt to the filter, others to the waste drain, or into a porous container. |
| Vacuum Control System | Intake manifold vacuum is used to operate dampers and controls in some automobile systems. |
| Vacuum Gauge | Instrument used to measure pressures below atmospheric pressure. |
| Vacuum Piping | The pipe from the suction side of a pump connected to a vacuum fitting located at the pool and below the water level to which underwater cleaning equipment may be attached. |
| Vacuum Pump | Special high efficiency device used for creating high vacuums for testing or drying purposes. |
| valance | A gathered or pleated panel that hangs above the curtain to hide the curtain rod. An attached valance is attached to the top of the curtain, but other types usually hang from the front edge of a valance shelf. Unlike a cornice, a valance is not rigid. |
| valance shelf | A board mounted above a window at right angles to the wall like a shelf. One or more rods, a cornice, a valance, a swag, or a covered cornice board may be attached to it. |
| Valley | 1. An elongated depression in the earth's surface between two raised areas. 2. A trough or internal angle formed by the intersection of two roof slopes. |
| Valley | The internal angle formed by the junction of two sloping sides of a roof. |
| Valley Flashing | Thin sheet metal used to line the valley of a roof. |
| Valley Rafter | A diagonal rafter that supports a roof valley. |
| Valuation | An inspection carried out for the benefit of the mortgage lender to ascertain if a property is a good security for a loan. |
| Valuation | The opinion of a real estate appraiser as to the value of a parcel of real property. |
| Valuation fee | The fee paid by the prospective borrower for the lender's inspection of the property. Normally paid upon loan application. |
| Value | 1. The worth of something measured monetarily. 2. Term used to distinguish dark colors from light ones; dark values are known as shades; light values as tints. |
| Value Engineering | The process of analyzing the cost versus the value and alternative materials, equipment, and systems. |
| Value of the Assets | The assets of a company in terms of dollar value. |
| Valve | Numerous mechanical devices by which the flow of liquid, gas, or loose material in bulk may be started, stopped, or regulated by a movable part that opens, shuts, or partially obstructs one or more passageways. |
| Valve Plate | Part of a compressor located between the top of the compressor body and the head, containing compressor valves and ports. |
| Valve Suction | See Suction Valve. |
| Valve, Expansion | See Expansion Valve. |
| Valve, Solenoid | See Solenoid Valve. |
| Valve, Suction | See Suction Valve. |
| Valve, Tapping | See Tapping Valve. |
| Valve, Water | See Water Valve. |
| Van Dyke Brown | A brown pigment which consists of decomposed vegetable matter that has almost approached the coal state; it is weak in hiding power compared to umber and sienna. |
| Vanadium | 1. A hard gray malleable ductile metallic element found in several ores and used as an alloy in small quantities for strengthening some steels. 2. Vanadium steel. |
| Vane | A revolving pointer mounted on a high place to show the direction of the wind. |
| Vanity Cabinet | Case, box, or piece of furniture which rests on the floor and receives a lavatory, commonly has shelves and doors and is primarily used as storage for below lavatory. |
| Vanity, Bath | See Bath Vanity. |
| Vapor | The gaseous state of any substance. |
| Vapor Barrier | 1. A material with a high resistance to vapor movement, such as foil, plastic film, or specially coated paper, that is used in combination with insulation to control condensation. 2. Any material that has a water vapor permeance (perm) rating of one or le |
| Vapor Compression Refrigeration | A cooling process that transforms heat from one location to another; heat is forced to flow from a region of lower temperature to a region of higher temperature; similar to a refrigerator for cooling food. |
| Vapor Degreasing | A cleaning process utilizing condensing solvent as the cleaning agent. |
| Vapor Lock | Condition where liquid is trapped in line because of bend or improper installation; such vapor prevents liquid flow. |
| Vapor Migration | The movement of water vapor from a region of high vapor pressure to a region of lower vapor pressure. |
| Vapor Pressure | Pressure imposed by either a vapor or gas. |
| Vapor Pressure Curve | Graphic presentation of various pressures produced by refrigerant under various temperatures. |
| Vapor Retarder | A layer of material intended to obstruct the passage of water vapor through a building assembly; also called a Vapor Barrier; sealing material placed between building components or materials to arrest movement of moisture within building enclosure assembl |
| Vapor Retarder Felt | Sealing material made of asphalt-saturated felt. |
| Vapor, Saturated | See Saturated Vapor. |
| Vaporization | Conversion from liquid or solid to a gaseous state. |
| Variable | Changing; subject to change, not constant; indeterminate. |
| Variable Air Volume (VAV) | An air handling system, unlike a single zone, terminal reheat, multi-zone, or dual duct, supplies air at a constant temperature and varies the air quantity supplied to each zone. |
| Variable Pitch Pulley | Pulley which can be adjusted to provide different pulley drive ratios. |
| Variable rate | An interest rate that will vary over the term of the loan. |
| Variable Rate Mortgage | A mortgage that allows the lender to raise or lower the interest rate from time to time as some specified index rises or falls. |
| Variance | A deviation in a building or zoning ordinance granted by an appeal authority upon relevant grounds being proven. |
| Varnish | A thickened preparation of drying oil or drying oil and resin suitable for spreading on surfaces to form continuous, transparent coatings, or for mixing with pigments to make enamels. |
| Varnish-Stain | Interior varnish tinted with pigments or dyes. |
| Varnishing | Application of varnish to a surface using a brush. |
| Vat Dyes | Dyes formed in fabrics by oxidation and precipitation of the original dye liquor, for example, indigo; vat dyeing refers to a kind of dye rather than a method of dyeing; raw stock dyeing, skein dyeing, or solution dyeing can be performed with vat dyes. |
| Vault | 1. An arched surface. 2. An arch translated along an axis normal to the plane of its centerline curve. 3. A room to store valuable items. |
| Vault Door | A hinged, pivoted, or sliding member that permits passage to an enclosure built for safety or security. |
| VAV | Variable Air Volume. |
| VCP | Vitreous Clay Pipe. |
| VDU | Video Display Unit. |
| Vector | 1. A quantity having direction as well as magnitude; usually represented by a line in space with an arrowhead indicating direction and the scale of the line representing magnitude. 2. A carrier of disease, such as a roach, rat, or mouse. |
| Vegetable Oils | Oils obtained from the seeds or nuts of vegetable growth, including linseed, soybean, perilla, tung, or castor. |
| Vegetation Control | The act or process of spraying chemicals or placing powders on unwanted vegetation. |
| Vehicle | 1. Any conveyance for transporting people or goods. 2. The liquid portion of paint and other finishing materials, consisting of the binder (nonvolatile) and thinners (volatile). |
| Vehicle | The liquid portion of a finishing material; it consists of the binder (nonvolatile) and volatile thinners. |
| Vehicle Lift | 1. An apparatus for lifting vehicles in order to have access to the carriage underneath. 2. A mechanical device used to move vehicles up and down in a parking structure. |
| Vehicular Way | A route used for vehicular traffic, such as a street, driveway or parking lot. |
| Veining | The characteristic stretch marks that develop during the aging process of soft bitumen. |
| Vellum | Fine parchment-like paper used for drawings for reproduction. |
| Vellum Glaze | A semi-mat glaze having a satin-like appearance. |
| Velocimeter | Instrument used to measure air speeds using a direct-reading air speed indicating scale. |
| Velocity | Speed, usually expressed in length units per time unit, like miles per hour or feet per second. |
| Velocity (of water in a stream) | The distance that water can travel in a given direction during an interval of time. |
| Velocity of Sound | A product of frequency times wavelength. |
| velour | A fabric with a thick pile that lies in one direction, it is made of cotton, wool or synthetic fibers. It is good for heavy curtains or tablecloths. |
| velvet | A closely woven pile fabric of cotton or synthetic fiber, it comes in a variety of weights and colors. It is best used flat or smoothly draped. A plain velvet used for upholstery can quickly look shabby, as the pile is flattened, while a light-colored vel |
| Velvet Carpet | A pile fabric woven on a velvet loom; it is the simplest of all carpet weaves and is used mostly for solid colors; woven with wires, a looped pile is created when the wires are withdrawn; a cut pile results when knife blades on the ends of the wires cut t |
| Veneer | 1. A thin layer, sheet or facing. 2. A thin layer or sheet of wood; usually one that has beauty or value and is intended to be overlaid on an inferior surface. 3. Nonstructural facing of brick, concrete, stone, tile, metal, plastic or other similar approv |
| Veneer Plaster | A wall finish system in which a thin layer of plaster is applied over a special gypsumboard base. |
| Veneer Plaster Base | A gypsumboard used as the base for application of a gypsum veneer plaster. |
| Veneer, Ashlar | See Ashlar Veneer. |
| Veneer, Brick | See Brick Veneer. |
| Veneer, Granite | See Granite Veneer. |
| Venetian Blind | A window blind which has numerous horizontal slats that may be set at several different angles in order to vary the amount of light admitted. |
| Venetian Red | Pigment with brick-red color made synthetically by calcining copperas and whiting. |
| Venetian Terrazzo | A mosaic type of terrazzo topping in which large chips of stone are incorporated. |
| Venetian window | See Palladian window. |
| Vent | 1. A vertical pipe connected to a waste or soil distribution system that prevents a back pressure or a vacuum that might siphon the water out of a trap. 2. Vertical pipe to provide passageway for expulsion of water vapor and vent gases from gas-burning eq |
| Vent | A pipe or duct which allows the flow of air and gasses to the outside. Also, another word for the moving glass part of a window sash, i.e. window vent. |
| Vent Cap | The top piece installed over the terminus of a ventilation pipe. |
| Vent Screed | A sheet metal plaster screed incorporating a vented section used chiefly in roof overhang soffits. |
| Vent Stack | A plumbing vent pipe in a multistory building, a separate pipe used for venting, that either connects with a stack vent above the highest fixture, or extends through the roof. |
| Vent, Foundation | See Foundation Vent. |
| Vent, Masonry | See Masonry Vent. |
| Vent, Roof | See Roof Vent. |
| Vent, Smoke | See Smoke Vent. |
| Vent, Soffit | See Soffit Vent. |
| Ventilated | Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes or vapors. |
| Ventilation Air | 1. The total volume of air in a system, which is a combination of the air brought into the system from the outdoors and the air that is being recirculated within the building. 2. The fresh air brought into the system from the outdoors. |
| Ventilator, Gravity | See Gravity Ventilator. |
| Ventilator, Relief | See Relief Ventilator. |
| Venting Clip | Clips to provide means to aid in curing and exiting of moisture from concrete or gypsum fill placed on a deck. |
| Venting of Roof Assembly | The necessary venting to eliminate moisture and vapor in roof systems. |
| Venturi | A short tube with a tapering constriction in the middle that causes an increase in the velocity of flow of a fluid and a corresponding decrease in fluid pressure. |
| Verdigris | 1. A green or bluish-green crystallized substance formed on copper by the action of acetic acid, used as a pigment. 2. Green oxidation on copper, bronze, or brass. |
| Verge Boards | The boards which serve as the eaves finish on the gable end of a building. |
| Vermiculite | A mineral closely related to mica, with the faculty of expanding on heating to form lightweight material with insulation quality; used as bulk insulation and also as aggregate in insulating and acoustical plaster and in insulating concrete floors. |
| Vermiculite Insulation | A loose mineral fill for thermal insulating applications. |
| Vermiculite Plaster | 1. A covering that is put on steel beams, concrete slabs, and other heavy construction materials, as a fire-retardant. 2. An insulating and soundproofing plaster. |
| Vermilion | Sulphide of mercury used as a pigment. |
| Vermont Slate | A fine grained thin-layered rock used for roofing, and paving. |
| Vernacular | The common building style of a period or place; concerned with ordinary rather than monumental buildings; vernacular architecture. |
| Vernier | A supplementary scale used on an instrument for obtaining fine adjustment. |
| Vertical | Perpendicular to the plane of the horizon; upright. |
| Vertical Angle | An angle in a vertical plane. |
| Vertical Application | Of gypsumboard, see Parallel Application. |
| Vertical Application of Roofing | Roll roofing laid parallel to the roof slope. |
| Vertical Bar | An upright reinforcing bar in a reinforced concrete shape. |
| Vertical blind | A blind vertically aligned vanes, made of either vinyl, fabric, or fabric inserted into vinyl. |
| Vertical Broken Joint | Style of laying tile with each vertical row of tile offset for half its length. |
| Vertical Check Valve | A device, mounted vertically, which allows fluid or air to pass through in only one direction. |
| Vertical Curve | The meeting of different gradients in a road or pipe. |
| Vertical Drains | Usually columns of sand used to vent water squeezed out of humus by weight of fill. |
| Vertical Forces | Loads imposed on a structure caused by gravity or the vertical component of wind or earthquake forces. |
| Vertical Joint | See Butt Joint, 4. |
| Vertical Lift Door | A door assembly on a lifting or hoisting device that is opened or closed, bottom to top or top to bottom. |
| Vertical Louver | A louver equipped with slats that are mounted vertically; see Louver. |
| Vertical Pattern | A spray pattern whose longest dimension is vertical. |
| Vertical Pipe | Any pipe or fitting which makes an angle at 45 degrees or less with the vertical. |
| Vertical Position | In pipe welding, the position of a pipe joint wherein welding is performed in the horizontal position and the pipe may or may not be rotated. |
| Vertical Reinforcing | Steel reinforcing bars in concrete, running vertically, perpendicular to the horizontal bars. |
| Vertical Shear | The sum of the algebraic forces that are one side of a given cross-section of a member. |
| Vertical Siding | Exterior wall covering attached vertically to the wood frame of a building or structure. |
| Vertical Slotted Shelf Standard | Metal strip with slots attached to vertical surfaces as the support part of adjustable shelf hardware. |
| Vertical Transportation | A general term for elevators, lifts, escalators, and dumbwaiters. |
| Vertical Wood Board and Batten Siding | Linear vertical wood boards with wood strips covering vertical joints used as an exterior cladding for a framed wall. |
| Vertical Wood Board Siding | Linear vertical wood material used as exterior surface or cladding for exterior framed wall. |
| Vertical-Grained Wood | Edge-grained lumber. |
| Vertically Laminated Wood | Laminated wood in which the laminations are so arranged that the wider dimension of each lamination is approximately parallel to the direction of load. |
| Vertiglide | A vertically installed Duette honeycomb shade, used mainly for sliding doors, made by Hunter Douglas. |
| Vessels | Wood cells of comparatively large diameter that have open ends and are set one above the other to form continuous tubes; the openings of the vessels on the surface of a piece of wood are usually referred to as pores. |
| Vestibule | An entrance to a house; usually enclosed. |
| Veterans Administration (VA) | A federal agency that insures mortgage loans with very liberal down payment requirements for honorably discharged veterans and their surviving spouses. |
| VG | Vertical Grain. |
| Vibration | 1. A periodic motion which repeats itself after a definite interval of time. 2. Energetic agitation of concrete to assist in its consolidation, produced by mechanical oscillating devices at moderately high frequencies. |
| Vibration Aresstors | Soft or flexible substance or device which will reduce the transmission of a vibration. |
| Vibration Detector | A part of a burglar alarm system. |
| Vibration Isolation | A method of isolating equipment from a structure to reduce the vibration transmission from the equipment, thus reducing the sound transmitted to the structure. |
| Vibration Isolator | A flexible device supporting vibrating mechanisms or machinery and reducing the vibrations transmitted to the rest of the building or structure. |
| Vibrator | Device for agitating wet concrete to eliminate air pockets. |
| Vibrator, External | See External Vibrator. |
| Vibrator, Internal | See Internal Vibrator. |
| Vicat Apparatus | A penetration device used to determine the setting characteristics of hydraulic cements. |
| Video Display Unit (VDU | ). 1. Cathode Ray Tube. 2. A television screen. 3. A computer monitor. |
| Vierendeel Truss | A rigid frame, used as a beam, assembled from parallel top and bottom chords tied together by vertical members. |
| Vignette | A roman-styled shade made by Hunter Douglas. |
| Vinyl | A plastic made by polymerization, used in flooring, wall coverings, gaskets, and miscellaneous parts. |
| Vinyl Asbestos Tile | Resilient floor tile consisting of vinyl reinforced with asbestos fibers. |
| Vinyl Coated Fence | A fence or enclosure built with posts and rails and covered with chain-link which has been factory coated with plastic. |
| Vinyl Coating | One in which the major portion of the binder is of a vinyl resin. |
| Vinyl Copolymer | Resins produced by copolymerizing vinyl monomers such as vinyl acetate and vinyl chloride. |
| Vinyl Faced Panel | Sheathing that has been covered by a flexible film or a liquid bonded by heat. |
| Vinyl Floor Tile | A resilient floor tile made of vinyl. |
| Vinyl Foam Cushioning | Carpet cushioning made from a combination of foamed synthetic materials. |
| Vinyl Gasket | A plastic seal between glass and aluminum. |
| Vinyl Resins | Synthetic resins made from vinyl compounds such as vinyl acetate. |
| Vinyl Sheet | The rolled form of vinyl. |
| Vinyl Sheet Floor | A thin sheet of vinyl used for the finish of floor surfaces. |
| Vinyl Sheetrock | Gypsumboard with a thin layer of vinyl as the finished surface. |
| Vinyl Siding | Exterior wall coverings made from a thermoplastic compound. |
| Vinyl Tile | A semi-flexible, resilient floor tile made from polymerized vinyl chloride, vinylide chloride, or vinyl acetate. |
| Vinyl Trim | Extruded vinyl moldings used for concealing edges, ends, joints, and corners of various sheet materials. |
| Vinyl Wall Covering | A tough, flexible and shiny film or liquid bonded by heat to a paper or fabric backing material. |
| Vinyl-Covered Gypsum Board | See Predecorated Wallboard. |
| Virgin Growth | The growth of mature trees in the original forests; to be distinguished from Second Growth. |
| Viscoelasticity | The ability of a material to simultaneously exhibit viscous and elastic responses to deformation. |
| Viscometer | An instrument for the measurement of Viscosity. |
| viscose (rayon) | Viscose is the oldest man-made fiber. It adds strength and luster to cotton and silk blends. Its distinctive sheen in used to highlight patterns, particularly in damask. |
| Viscosity | Internal friction in a fluid; resistance to flow; the ratio of the shear stress existing between laminae of moving fluid and the rate of shear between these laminae. |
| Viscosity Cup | A device for measuring viscosity. |
| Viscosity Grading | A classification system of asphalt cements based on viscosity ranges at 140°F (60°C); a minimum viscosity at 275°F (135°C) is also usually specified; the purpose is to prescribe limiting values of consistency at these two temperatures; . 140° F approximat |
| Viscount blinds | 5 gauge contract blind made by hunter Douglas. |
| Vise | Bench tool with two jaws that can be closed by turning a screw, for holding work. |
| Vise Grip | A pliers-like hand tool that has great gripping power through a simple system of highly efficient leverage. |
| Vision Panel | Glass placed in an opening of a door. |
| Visqueen | A 4 mil or 6 mil plastic sheeting. |
| Visual Aid Board | A display that has information posted on it with writing, diagrams or pictures to dispense helpful facts. |
| Vitreous | That degree of vitrification evidenced by low water absorption; vitreous generally signifies less than 0.5% absorption, except for floor and wall tile and low-voltage electrical porcelain which are considered vitreous up to 3.0% water absorption. |
| Vitreous China | The material of a china plumbing fixture with a finish resembling glass, in color, composition, brittleness, and low porosity, used for toilets, urinals, and lavatories. |
| Vitreous Enamel | A fired-on opaque glassy coating on metal, such as steel. |
| Vitreous Slip | A slip coating matured on a ceramic body, producing a vitrified surface. |
| Vitreous Tile | Tile with water absorption of more than 0.5%, but not more than 3.0%. |
| Vitrification | The progressive reduction in porosity of a ceramic composition as a result of heat treatment, or the process involved. |
| Vitrification Range | The maturing range of a vitreous body, producing a vitrified surface. |
| Vitrified | That which is fused by heat; well burned to a greater degree of hardness. |
| Vitrified Clay Pipe | Pipes used especially for underground drainage, that are made of hard baked clay. |
| VM&P Naphtha | Varnish and paint manufacturers naphtha; a low power flammable hydrocarbon solvent. |
| VOCs | Volatile Organic Compounds. |
| Void | 1. An unfilled space in a material, of trapped air or other gas. 2. In gypsumboard, a hollow space in the core caused by the entrapment of air during the manufacturing process. 3. In concrete, air spaces resulting from segregation and improper consolidati |
| Void Volume | Total empty spaces in a compacted mix. |
| Voidable | A valid provision of a contract that can be made void by following some specified procedure. |
| voile | A light plain-weave cotton or man-made fabric. Suitable for sheer curtains. |
| Volatile Content | Those materials which evaporate; usually expressed as a percentage. |
| Volatile Flammable Content | A flammable liquid having a flash point below 100°F. (37.8°C.) or a liquid whose temperature is above its flash pint. |
| Volatile Organic Compounds (VOCs) | Compounds that evaporate from the many housekeeping, maintenance, and building products made with organic chemicals; these compounds are released from products that are being used and that are in storage; in sufficient quantities, VOCs can cause eye, nose |
| Volatile Thinner | A liquid that evaporates readily and is used to thin or reduce the consistency of finishes without altering the relative volumes of pigments and nonvolatile vehicles. |
| Volatiles | Fluids which evaporate rapidly. |
| Volcanic Ash | A fine powder similar to diatomite but lighter in weight, it is used as a filter medium or filter aid in diatomite filters. |
| Volt | A unit of electrical potential difference; the SI unit of electromotive force; the difference of potential that would carry one ampere of current against one ohm resistance. |
| Voltage | 1. Term used to indicate the electrical potential or electromotive force in an electrical circuit. 2. Voltage or electrical pressure which causes current to flow. 3. Electromotive force. |
| Voltage Control | Device used to provide some electrical circuits with uniform or constant voltage. |
| Voltage Drop | Loss of voltage due to length of run or resistance. |
| Voltage Regulator | An automatic electrical control device for maintaining a constant voltage supply to the primary of a welding transformer. |
| Voltage to Ground | In grounded circuits the voltage between the given conductor and that point or conductor of the circuit which is grounded; in ungrounded circuits, the greatest voltage between the given conductor and any other conductor of the circuit. |
| Voltmeter | An instrument for measuring in volts the differences of potential between different points of an electrical circuit. |
| Volume | The amount of space occupied by a three dimensional solid or gas, measured in cubic units like cubic feet or cubic centimeters. |
| Volume Ceiling | Any ceiling higher than the normal. |
| Volumetric Efficiency | The relationship between the actual performance of a compressor or of a vacuum pump and calculated performance of the pump based on its displacement. |
| Volute | 1. A spiral scroll characteristic of Ionic capitals, also used in Corinthian and composite capitals. 2. A spiral or scroll-shaped form, as in volute pumps. |
| Vomitory | One of the passages for entrance and exit in a theater or amphitheater. |
| Vortex Tube | Mechanism for cooling or refrigerating which accomplishes cooling effect by releasing compressed air through a specially designed tube. |
| Vortex Tube Refrigeration | Refrigerating or cooling device using principle of vortex tube, as in mining suits. |
| Voussoir | One of the wedge-shaped pieces of stone or brick forming an arch. |
| VRM | Variable Rate Mortgage. |
| VTR | Vent through roof. |
| Vulcanizing | Treating rubber with sulphur at a high temperature to harden and toughen it. |