Glossary: C


Cable TrayA ladderlike metal frame, open on the top, used to support insulated electrical cables.
CABOCouncil of American Building Officials Association, made up of representatives from three model codes. Issues National Research Board (NRB) research reports.
CaissonA watertight structure within which work can be carried out below the surface of water.
Calcareous ClaysClays containing at least 15 percent calcium carbonate.
Calcined GypsumGround gypsum that has been heated to drive off the water content.
CamberCurvature built into a beam or truss to compensate for loads that will be encountered when in place and load is applied. The crown is placed upward. Insufficient camber results in unwanted deflection when the member is loaded.
CandelaA metric unit of luminous intensity that closely approximates candlepower.
CandlepowerA term used to express the luminous intensity of a light source. It is the same magnitude as a candela.
Cant BeamBeam with edges chamfered or beveled.
Cant StripTriangular section laid at the intersection of two surfaces to ease or eliminate effect of a sharp angle or projection.
Capillary ActionThe movement of a liquid through small openings of fibrous material by the adhesive force between the liquid and the material.
Capillary BreakA groove in a member used to create an opening that is too wide to be bridged by a drop of water, thus eliminating the passage of water by capillary action.
Car Safeties, ElevatorDevices used to stop a car and hold it in position should it travel at an excessive speed or go into a free fall.
Car, ElevatorThe load-carrying unit of an elevator, consisting of a platform, walls, ceiling, door, and a structural frame.
Carbon SteelAny steel for which no minimum content for alloying agents is specified, but for which the carbon content is the element used to determine its properties.
Carrying ChannelMain supporting member of a suspended ceiling system to which furring members or channels attach.
CasementGlazed sash or frame hung to open like a door.
CasingThe trim around windows, doors, columns or piers.
Cast IronA hard, brittle metal made of iron that contains a high percentage of carbon.
Cast-In-Place ConcreteConcrete members formed and poured on the building site in the locations where they are needed.
Cast-In-Place PilesConcrete piles cast in a hollow metal shell driven into the earth or an uncased hole.
CastingA metal part produced by pouring a molten metal into a mold.
Catch BasinA drainage device used to collect water, with a deep pit to catch sediment.
CaulkingA resilient material used to seal cracks and prevent leakage of water.
Cavity WallA masonry wall made up of two wythes of masonry units separated by an air space.
CementA material that is able to unite nonadhesive materials into a solid mass.
Cement BoardA factory-manufactured panel, 1/4″ to 3/4″ thick, 32″ to 48″ wide, and 3′ to 10′ long, made from aggregated and reinforced portland cement.
Cement-Lime MortarMortar made with the addition of slaked lime to the cement.
Cementitious MaterialsMaterials that have cementing properties.
Central Service CoreA fire-resistant vertical shaft through a multistory building used to route electrical, mechanical, and transportation systems.
CentroidThe point in a cross-section where all of the area may be considered concentrated without affecting the moment of the area about any axis.
CeramicA class of products made of clay fired at high temperatures.
Ceramic GlazeA compound of metallic oxides, chemicals, and clays fused to a material at high temperature, providing a hard, smooth surface.
Chalk LineStraight working line made by snapping a chalked cord stretched between two points, transferring chalk to work surface.
ChaseA recessed area in a wall for holding pipes and conduit that passes vertically between floors.
Chemical StrengtheningA process for strengthening glass that involves immersing the glass in a molten salt bath.
ChillerA refrigerating machine composed of a compressor, a condenser, and an evaporator, used to transfer heat from one fluid to another.
Chord, BottomA horizontal or inclined structural member forming the lower edge of a truss.
Chord, TopA horizontal or inclined structural member forming the top edge of a truss.
Circuit BreakerAn electrical device used to open and close a circuit by nonautomatic means or to open a circuit by automatic means at a predetermined overcurrent without damage to itself.
CirculationThe flow or movement of people, goods, vehicles, etc., from place to place.
CladdingA nonload-bearing exterior wall enclosing a building. It may be brick, aluminum, steel, bronze, plastic, glass, stone, or other acceptable material.
Class A,B,C RoofingClassification of roofing materials by their resistance to fire when tested in accordance with ASTM E108.
ClayA very cohesive material made up of microscopic particles (less than 0.00008 inches or 0.002 mm).
Clay TileA unit made from fired and sometimes glazed clay and used as a finish surface on floors and walls.
CleanoutsOpenings in the waste piping system that permit cleaning obstructions from the pipe.
Clear CoatingA transparent protective and/or decorative film.
Clear SpanThe horizontal distance between the interior edges of supporting members.
Coal TarTar produced through the destructive distillation of coal during the conversion of coal to coke.
Coal Tar PitchA dark brown to almost black hydrocarbon material derived by distilling coke-oven tar.
CoatingA paint, varnish, lacquer, or other finish used to create a protective and/or decorative layer.
Coefficient of Heat Transmission (U)Total amount of heat that passes through an assembly of materials, including air spaces and surface air films. Expressed in Btu per hr., per sq. ft., per °F temperature difference between inside and outside air (beyond the surface air films). “U” values are often used to represent wall and ceiling assemblies, floors and windows. Note: “k” and “C” values cannot simply be added to obtain “U” values. “U” can only be obtained by adding the thermal resistance (reciprocal of “C”) of individual items and dividing the total into 1.
Coefficient of Hygrometric ExpansionSee Hygrometric Expansion.
Coefficient of RunoffA fixed ratio of total rainfall that runs off a surface.
Coefficient of Thermal Conductance (C)Amount of heat (in Btu) that passes through a specific thickness of a material (either homogeneous or heterogeneous) per hr., per sq. ft., per °F. Measured as temperature difference between surfaces. The “C” value of a homogeneous material equals the “k” value divided by the material thickness: C = k/t (where t = thickness of material in inches)It is impractical to determine a “k” value for some materials such as building paper or those only used or formed as a thin membrane, so only “C” values are given for them.
Coefficient of Thermal Conductivity (k)Convenient factor represents the amount of heat (in Btu) that passes by conduction through a one inch thickness of homogeneous material, per hr., per sq. ft., per °F. Measured as temperature difference between the two surfaces of the material.
Coefficient of Thermal ExpansionSee Thermal Expansion.
CofferdamA temporary watertight enclosure around an area of water-bearing soil or an area of water from which water is pumped allowing construction to take place in the water-free area.
Cogeneration SystemsSystems using fossil fuel, geothermal energy, wind, or solar energy to produce electricity and heat.
CohesionThe molecular forces between particles within a body which acts to unite them.
Cohesionless SoilA soil that when unconfined has little or no cohesion when submerged and no significant strength when air dried.
Cohesive SoilA soil that when unconfined has considerable cohesion when submerged and considerable strength when air dried.
Cold-Rolled SteelSteel rolled to the final desired shape at a temperature at which it is no longer plastic.
Collector StreetA street into which minor streets empty and which leads to a major arterial.
ColumnVertical loadbearing member.
Combined SewerSewer that carries both storm water and sanitary or industrial wastes.
Comfort ZoneAny combination of temperature and himidity in which the average person feels comfortable.
CompactionCompressing soil to increase its density.
CompartmentA small area within a larger area enclosed by partitions.
Composite MaterialsMaterials made by combining several layers of different materials.
Composite PanelsPanels having a reconstituted wood core bonded between layers of solid veneer.
CompressionThe conditions of being shortened (compressed) by force.
Compression TestA test used to determine the behavior of materials under compression.
Compressive StrengthMeasures maximum unit resistance of a material to crushing load. Expressed as force per unit cross-sectional area, e.g., pounds per square inch (psi).
Compressive StressesStresses created when forces push on a member and tend to shorten it.
CompressorA mechanical device for increasing the pressure of a gas.
Concentrated LoadAny load that acts on a very small area of a structure.
ConcreteA mixture of fine and course aggregates, portland cement, and water.
Concrete FootingGenerally, the wide, lower part of a foundation wall that spreads the weight of the building over a larger area. Its width and thickness vary according to weight of building and type of soil on which building is erected.
Concrete MasonryFactory manufactured concrete units, such as concrete brick or block.
Concrete PumpA pump that moves concrete through hoses to the area where it is to be placed.
CondemnationTaking private property for public use, with compensation to the owner, under the right of eminent domain.
CondensateA liquid formed by the condensation of vapor.
CondensationThe process of changing from a gaseous to a liquid state.
Condensation PointThe temperature at which a vapor liquefies if the latent heat is removed at standard ora stated pressure.
CondenserA heat-exchanger unit in which a vapor has some heat removed, causing it to form a liquid.
ConductionThe transfer of heat by direct molecular action.
Conduction, ThermalTransfer of heat from one part of a body to another part of that body, or to another body in contact, without any movement of bodies involved. The hot handle of a skillet is an example. The heat travels from the bottom of the skillet to the handle by conduction.
Conductivity, ElectricA measure of the ability of a material to conduct electric current.
Conductor, ElectricWire through which electric current flows.
ConduitA steel or plastic tube through which electrical wires are run.
Conforming UseLawful use of a building or lot that complies with the provisions of the applicable zoning ordinance.
ConiferousDescribing a cone-bearing tree or shrub.
ConsolidationThe process of compacting freshly placed concrete in a form.
ContourA line on a plan that connects all points of equal elevation.
Contour IntervalThe vertical distance between adjacent contour lines.
Control JointA groove formed in concrete or masonry structures to allow a place where cracking can occur, thus reducing the development of high stresses.
ControllerAn electric device or a group of devices used to govern the electric power delivered to the equipment to which it is connected.
ConvectionProcess of heat carried from one point to another by movement of a liquid or a gas (i.e., air). Natural convection is caused by expansion of the liquid or gas when heated. Expansion reduces the density of the medium, causing it to rise above the cooler, more dense portions of the medium. Gravity heating systems are examples of the profitable use of natural convection. The air, heated by the furnace, becomes less dense (consequently lighter) and rises, distributing heat to the various areas of the house without any type of blower. When a blower is used, the heat transfer method is called “forced convection.”
ConvectionThe process of carrying heat from one spot to another by movement of a liquid or gas. The heated liquid or gas expands and becomes lighter, causing it to rise while the cooler, heavier dense liquid or air settles.
ConvectorA unit designed to transfer heat from hot water or steam to the air by convection.
Cooling TowerA heat-transfer device in which the atmospheric air cools warm water flowing through the tower, usually by evaporation.
Corner BraceStructural framing member used to resist diagonal loads that cause racking of walls and panels due to wind and seismic forces. May consist of a panel or diaphragm, or diagonal flat strap or rod. Bracing must function in both tension and compression. If brace only performs in tension, two diagonal tension members must be employed in opposing directions as “X” bracing.
Corner LotA land parcel that fronts on two contiguous streets. The short side is generally considered to be the front of the lot.
Corner PostTimber or other member forming the corner of a frame. May be solid or built-up as a multi-piece member.
CorrosionThe deterioration of a metal or of concrete by chemical or electrochemical reaction caused by exposure to the weather.
Covalent BondingA process in which small numbers of atoms are bonded into molecules.
CovenantA restriction of the deed which regluates land use, aesthetic qualities, etc., of an area.
CreepPermanent dimensional deformation occurring over a period of time in a material subjected to constant stress at elevated temperatures.
Creep TestA test to determine the creep behavior of materials subjected to constant stress at a constant temperature.
CricketA small false roof used to divert water from behind a projection above the roof, such as a chimney.
CrippleShort stud such as that used between a door or window header and the top plate.
CrownThe central area of a conve surface, such as a road.
Cul-De-SacA short road with an outlet on one end and a turnaround on the other.
CulvertA length of pipe under a road or other barrier used to convey water.
CupolaA small roofed structure built on top of a roof, usually to vent the area below the roof.
CurbA low wall of wood or masonry extending above the level of the roof and surrounding an opening in the roof.
Curb CutA depression in a curb that provides vehicular access from a street to a driveway.
CureTo chemically cross-link polymer chains by heating and/or adding a chemical agent.
CuringProtecting concrete after placing so that proper hydration occurs.
Curing AgentPart of a two-part compound that, when added to the second part, sets up the curing action Also referred to as the catalyst.
Current, ElectricThe flow of electrons along a conductor.
Curtain WallExterior wall of a building that is supported by the structure and carries no part of the vertical load except its own. Curtain walls must be designed to withstand wind loads and transfer them to the structure.
Cut and FillIn grading, earth that is removed (cut) or added (fill).
Cycle (Acoustic)One full repetition of a motion sequence during periodic vibration. Movement from zero to +1 back to zero to -1 back to zero. Frequency of vibration is expressed in Hertz (cycles per second — see Frequency).