Glossary of Terms provided by KDW, Ltd.

Glossary of Terms

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A
Absorption	When sound waves contact a room surface such as a ceiling, wall or floor, a portion of the sound energy is reflected back into the room, and the rest is considered to be absorbed primarily by conversion into heat due to friction within a porous material, or by vibration of a solid material
Acceleration	A period which the elevator moves at an ever increasing rate of speed, usually referring to that period from standstill to full speed
Accelerators	Material additives used to accelerate, or reduce, the setting time of concrete causing it to harden faster. Accelerators often include calcium chloride, or aluminum sulfate or other acidic materials
Accessory	A building product which supplements a basic solid panel building such as a door, window, light transmitting panel, roof vent, etc.
Acoustical Material	Any material that affects the sound level or direction of travel of a sound wave. Some acoustical materials are specifically characterized as sound absorbers, or sound reflectors, or as barriers to sound passage.
ADA	The Americans with Disabilities Act which gives civil rights protection to individuals with disabilities similar to those provided to individuals on the basis of race, color, sex, national origin, age, and religion. It guarantees equal opportunity for individuals with disabilities in public accommodations, employment, transportation, State and local government services, and telecommunications.
Admixture	A material, other than aggregate, cement, or water, added in small quantities to the mix in order to produce some desired modifications, either to the physical or chemical properties of the mix or of the hardened product. The most common admixtures affect plasticity, air entrainment, and curing time. These admixtures are often referred to as plasticizers, superplasticizers, accelerators, dispersants, and water-reducing agents.
Aggregate	A mixture of sand, rock, gravel, cobble, boulder size particles, crushed stone, expanded materials, or particles that typically compose 75% of concrete by volume improve the formation and flow of cement paste and improve the concrete's structural performance. Aggregates are typically inorganic, natural (e.g. gravel), processed (e.g. crushed rock) or man-made (e.g. air-cooled blast furnace slag and expanded shale).
Air Balance	HVAC term for distributing air through a system to precisely match the required amount.
Air Conditioner	A device used to control temperature and humidity of the air.
Air Conditioning	In HVAC the control of the quality, quantity, and temperature-humidity of the air in an interior space.
Air Exchange Rate	In HVAC the rate at which outside air replaces indoor air in a space. Expressed in one of two ways: the number of changes of outside air per unit of time - air changes per hour (ACH); or the rate at which a volume of outside air enters per unit of time - cubic feet per minute (CFM).
Air Handler	HVAC term for a fan-blower, heat transfer coil, and housing parts of a system.
Air Handling Unit (AHU)	In HVAC refers to equipment that includes a blower or fan, heating and/or cooling coils, and related equipment such as controls, condensate drain pans, and air filters. Does not include ductwork, registers or grilles, or boilers and chillers.
Air Infiltration	The unwanted entrance of air due to leakage, temperature difference, or wind.
AISC (American Institute of Steel Construction, Inc.)	Is a non-profit technical specifying and trade organization for the fabricated structural steel industry in the United States. It was founded in 1921 with headquarters located in Chicago. One of their best known manuals is the Manual of Steel Construction.
Allowance(s)	A sum of money set aside in the construction contract for items which have not been selected and specified in the construction contract. For example, selection of tile as a flooring may require an allowance for an underlayment material, or an electrical allowance which sets aside an amount of money to be spent on electrical fixtures.
American Concrete Institute (ACI)	An international organization dedicated to providing knowledge and information for the best uses of concrete.
American Standard of Testing Materials (ASTM)	An organization that has developed a variety of methods for testing the strength of cement and other building materials to ensure it complies with needed strength requirements
Anchor Bolt	Bolts used to anchor members to a foundation or other support. A long 'L' shaped bolt which is set in concrete and used to anchor columns or other members to a foundation or other support. Bolts to secure a wooden sill plate to concrete , a masonry floor or wall.
Angle Mounted Track	A method of fastening vertical track to a doorjamb using a full height continuous angle.
Apron	A slab of concrete extending beyond the entrance to a building, particularly at an entrance for vehicular traffic. At an airport, the pavement adjacent to hangars and appurtenant buildings.
Architect	One who has completed a course of study in building and design, and is licensed by the state as an architect. One who draws up plans.
Arcing	Current passing (through air) across a gap, that is, using the air itself like a wire.
As-Built Drawings (also known as Record Drawings)	Contract drawings marked up to reflect changes made during the construction process. It is good practice to make As-Built drawings by marking the changes on reproducible drawings such a sepias for the duplication purposes later.
Asphalt	A black petroleum residue, which can be anywhere from solid to semisolid at room temperature. When heated to the temperature of boiling water, it becomes able to be poured. It is used in roofing materials, surfacing roads, in lining the walls of water-retaining structures such as reservoirs and swimming pools, and in the manufacture of floor tiles. Asphalt should not be confused with tar, a similar looking substance made from coal or wood and incompatible with petroleum derivates.
Astragal	Weather-stripping added to bottom section of the door to seal the opening along the floor.
Attenuation	A reduction in sound level (loudness) as a result of any of the following 1) with increasing distance away from a source (expanding waves); 2) as sound is partially absorbed upon reflection off a surface; or 3) as sound passes through a barrier material such as drywall or glass
Auxiliary Crane Girder	A girder arranged parallel to the main girder for supporting the platform, motor base, operator's cab, control panels, etc., to reduce the torsional forces that such a load would otherwise impose on the main crane girder.
Auxiliary Hoist	A supplemental hoisting unit usually designed to handle lighter loads at a higher speed than the main hoist.
B	Back To Top
Back Flow Preventer	A device to prevent water from traveling from one system back into any part of the main distribution system, usually by siphoning, esp. into a potable water supply. This is generally required for sprinkler systems, handheld showers, pullout faucet spouts, kitchen sprayers, etc.
Backfill	Earth or other material used to replace material removed during construction, such as in pipeline and culvert trenches and behind retaining walls.
Backing board	Gypsum wallboard designed to be the first layer in a multilayer wall system
Backslope	The non-horizontal finish grade of soils behind a wall; typically expressed as horizontal distance to vertical height (2; 1 backslope); used in engineering calculations, backslope increases the design load on a wall. Also referred to as top slope.
Baked Enamel	An enamel paint that must be baked to adhere to the surface
Balance Site	The act of using only onsite materials (no “import” or “exporting” of materials) to shape the existing sub-grade materials for proper drainage
Bar Joist	A name commonly used for Open Web Steel Joists
Base Angle	An angle secured to a wall or foundation used to attach the bottom of the wall paneling.
Base Cabinet	Any cabinet type designed to install directly on the floor. It will generally have some kind of countertop such as laminate, wood or granite.
Batch	The quantity produced as the result of one mixing operation, as in a batch of concrete.
Bay	The distance between the main frames of a building.
Beam	A structural member, usually horizontal, whose main function is to carry loads transverse to its longitudinal axis. These loads usually cause bending of the beam member. Some types of beams are simple, continuous, and cantilever.
Beam and Column	A Structural system consisting of a series of rafter beams supported by columns. Often used as the end fame of a building.
Beam-Column	A structural member whose main function is to carry loads both parallel and transverse to its longitudinal axis.
Bearing End Frame	See Beam and Column
Best Management Practice (BMP)	Best Management Practice - often referred to in erosion and sediment control applications.
Bevel Edge	An acoustical tile is considered bevel edge material when the face of the tile turns up at the edge at approximately 45 degrees for 1/8" to 1/4" around the perimeter of the tile.
Bi-Fold Door	Two doors connected with hinges, enabling them to fold together. Typically attached to a track and hanger fastened to the header. We recommend using a Cased Opening w/Stop Frame. This hides track and hangers.
Bid Bond	A written form of security executed by the bidder as principal and by a surety for the purpose of guaranteeing that the bidder will sign the contract, if awarded the contract, for the stated bid amount.
Bird Screen	Wire mesh used to prevent birds from entering the building through ventilators and louvers.
Block out	The installing of a box or barrier within a foundation wall to prevent the concrete from entering an area. For example, foundation walls are sometimes "blocked" in order for mechanical pipes to pass through the wall, to install a crawl space door, and to depress the concrete at a garage door location.
Blocking	Light lumber strips nailed between major framing members to support edges of structural panels where they meet.
Blower	In HVAC the device in an air conditioner that distributes the filtered air from the return duct over the coil/heat exchanger. This circulated air is cooled/heated and then sent through the supply duct, past dampers, and through supply diffusers to the living/working space.
Boiler	A sealed tank where water is heated and turned to steam for power or hot water.
Bond	The adhesion of cement paste to aggregate and or the rebar. See aggregate and rebar.
Bond Beam	The top course of block of a masonry wall filled with concrete and reinforcing steel and used to support roof loads.
Bond breaker	A strip of material to which the cement does not adhere
Booster/Jockey Pump	An auxiliary pump used to maintain system pressure without starting the main pump. These pumps are not designed to keep up with full system demand, their only function is system pressure maintenance.
Border Cut	Cut made on both ceiling panel and grid at the perimeter of the installation.
Brace/bracing	A concrete forming accessory that acts as a temporary support for aligning vertical concrete formwork. One end of the brace attaches to the form and the other anchors to the ground
Bracket	A structural support projecting from a structural member. Examples are canopy brackets, lean-to brackets, and crane runway brackets,
Brackets (Guide Rail)	The device used to attach the rails firmly to the hoistway.
Brake	A device, other than a motor, used for retarding or stopping motion by friction or power means. Elevators: An electro-mechanical device used to prevent the elevator from moving when the car is at rest and no power is applied to the hoist motor. On some types of control, it also stops the elevator when power is removed from the hoist motor with a spring-loaded clamping device that holds the elevator car when the machine is turned off;
Branch Circuit	The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).
Breaker	An automatic switching device that disconnects power to a circuit when current or heat exceeds a certain level for a certain amount of time. It clips on to one or two live busbars in a panel box and passes this liveness through itself to the circuit wire attached to it, normally by means of a screw. Its handle is generally in one of three positions on, tripped (the middle position), and off.
Bridge (Crane)	That part of an overhead crane consisting of girders, end trucks, end ties, walkway and drive mechanism which carries the trolley and travels in a direction parallel to the runway.
Bridge Crane	A lifting system which has a hoist that moves laterally on a beam or other member which then in turn moves longitudinally on a runway made of beams and rails.
Bridge Rail	The rail supported by the bridge girders on which the trolley travels.
Bridging	In general, is a member connected to a joist to brace it from lateral movement. See Horizontal Bridging and Diagonal Bridging.
British Thermal Unit (BTU)	The amount of heat required to raise the temperature of one pound of water one degree Fahrenheit, equal to 252 calories.
Broom finish	Concrete that has been brushed with a broom when fresh in order to improve its traction or to create a distinctive fine-lined texture.
Building Code	Regulations established by a recognized agency describing design loads, procedures, quality of materials, and construction details for buildings for the protection of the public.
Building Envelope	Elements of the building, including all external building materials, windows, and walls, that enclose the internal space.
Built-Up Roof	A type of roof composed of two or more layers of alternating felt, tar and asphalt.
Built-Up Section	A structural member, usually an "I" shaped section, made up from individual flat plates welded together or any structural metal elements that are welded or bolted together.
Bullnose	A radius (curved) finished edge. A trim tile with a convex radius or finished edge on one side. Used for finishing top of wainscot, turning of an outside corner, or floor base.
Bumper (Buffer)	An energy absorbing device for reducing impact when a moving crane or trolley reaches the end of its permitted travel, or when two moving cranes or trolleys come into contact
Busbar	A piece of rigid metal within a panel or fusebox which distributes electricity to the various circuits by means of their connection to it.
Bypass Girt	A wall framing system where the girts are mounted on the outside of the columns.
C	Back To Top
"C" Section	A member in the shape of a block "C" formed from steel sheet, that may be used either singularly or back to back.
C Shapes	A hot rolled shape called an American Standard Channel with symbol C.
Cab	The decorative room in which people ride in a passenger elevator
Camber	Curvature of a flexural member in the plane of its web before loading.
Canopy	A projecting roof system that is supported and restrained at one end only.
Cantilever Beam	A beam supported only at one end with the other end free to move.
Capacity	The maximum rated load which a crane is designed to handle. Elevators: Indicates the amount of weight a given elevator is able to support safely.
Car (elevator)	The load-carrying unit, including its platform, frame, enclosure, and car door or gate.
Cased Opening	A three sided frame without hinge or strike preparations. Note: Must specify with or without stop when ordering.
Cast-in-place concrete	Concrete that is poured into forms that are erected at the job site. It is the same as the term sitecasting
Casting bed	A permanent, fixed form, in which permanent pre-cast concrete forms are produced
Catwalk	Suspended structural framing used to provide access to and between areas below a roof and above a floor.
Caulk	Waterproof sealant used to fill joints or seams. Caulks are available as putties, ropes, or compounds extruded from cartridges.
Ceiling Plenum	Space below the flooring and above the suspended ceiling that accommodates the mechanical and electrical equipment and that is used as part of the air distribution system. The space is kept under negative pressure.
Cement	A material composed of fine ground powders that hardens when mixed with water. Cement is only one component of concrete. The gray powder that is the "glue" in concrete.
Cement slurry	A thin, watery cement mixture for pumping or for use as a wash over a surface.
Cement - Type I Normal	is a general purpose cement suitable for practically all uses in residential construction but should not be used where it will be in contact with high sulfate soils or be subject to excessive temperatures during curing.
Cement - Type II Moderate	is used where precaution against moderate sulfate attack is important, as in drainage structures where sulfate concentrations in groundwater's are higher than normal.
Cement - Type III High Early Strength	is used when high strengths are desired at very early periods, usually a week or less. It is used when it is desirable to remove forms as soon as possible or to put the concrete into service quickly.
Cement - Type IV Low Heat	is a special cement for use where the amount and rate of heat generated during curing must be kept to a minimum. The development of strength is slow and is intended in large masses of concrete such as dams.
Cement - Type V Sulfate Resisting	is a special cement intended for use only in construction exposed to severe sulfate action, such as western states having soils of high alkali content.
Central Air Handling Unit (Central AHU)	This is the same as an Air Handling Unit, but serves more than one area.
Chain Hoist	Adds mechanical advantage to manually operated doors. Couples to one end of the solid torsion shaft.
Chair	A small metal or plastic support for reinforcing steel in concrete construction. The support is used to maintain proper positioning during concrete placement
Check Valve	A type of backflow preventer installed in a pipe run that allows water to flow in only one direction.
Chemical stabilization	Making something stronger or less affected by outside conditions with the addition of chemicals
Circuit	The actual or intended path of current between points of differing voltage. In the case of a household 120 volt circuit, the path is between a hot wire at the breaker and a neutral wire connected to the grounded neutral bar in the panel. In a sense each loop that current makes (through a single light, for instance) is a circuit, but the most common meaning is the "branch circuit", defined as everything fed (or interrupted) by a given breaker or fuse.
City By-Pass	A fire pump system piping configuration which allows water from the city supply to by-pass the fire pump and feed the sprinkler system. Used as a back-up while the fire pump is under maintenance, in case of power failure, or in conjunction with an FDC to ensure at least some water makes it to the sprinklers.
Cladding	The exterior covering of the structural members of a building.
Clearance	Minimum distance from the extremity of a crane to the nearest obstruction.
Closure Strip	A strip, formed to the contour of ribbed panels and used to close openings created by ribbed panels joining other components, either made of resilient material or metal.
CMAA	Crane Manufacturers Association of America.
Cold joint	A visible line that forms when the placement of concrete is delayed. The concrete in place hardens prior to the next placement of concrete against it.
Cold-Formed	The process of forming a structural section by bending sheet or strip steel in roll-forming machines without the use of heat.
Collateral Loads	The weight of additional permanent materials required by the contract, other than the Building System, such as sprinklers, mechanical and electrical systems, partitions and ceilings.
Column	Is a main vertical member carrying axial loads, which can be combined with bending and shear, to transfer loads from the main roof beams, trusses, rafters or girders to the foundation. These structural members carry loads parallel to its longitudinal axis.
Common	The terminal of a three-way switch (or the wire attached to it) which makes internal contact with one or the other of the traveler terminals, depending on the position the switch is moved to.
Common Vent	Building drain system vertical vent which connects two or more fixture branches on the same level.
Compaction	The elimination of voids in construction materials, as in concrete, plaster, or soil, by vibration, tamping, rolling, or some other method or combination of methods. The process of eliminating voids in the non-set concrete mixture that has been placed often using various vibration devices. A sister operation to placing, compaction rates should be about equal to the time it takes to place
Components and Cladding	Members which include girts, joists, purlins, studs, wall and roof panels, fasteners, end wall columns and endwall rafters of bearing end frames, roof overhang beams, canopy beams, and masonry walls that do not act as shear walls.
Composite Beam	A steel beam and a concrete slab connected, usually by shear stud connectors, so that they act together to resist the load on the beam.
Compression Fitting	A kind of tubing or pipe connection where a nut, and then a sleeve or ferrule is placed over a copper or plastic tube and is compressed tightly around the tube as the nut is tightened, forming a positive grip and seal without soldering. Also a flexible connector that has a nut and gasket designed to attach directly to an SAE standard compression thread, without the use of a sleeve or ferrule.
Compressor	A device used to compress air for mechanical or electrical power production, and in air conditioners, heat pumps, and refrigerators to pressurize the refrigerant and enabling it to flow through the system.
Concealed Clip	A hold down clip used with a wall or roof panel system to connect the panel to the supporting structure without exposing the fasteners on the exterior surface.
Concealed Mounting System	Tile suspension system using T-Bars and splines which fit into kerfs cut into tile edges. Unlike exposed-grid systems, concealed mounting systems are not visible from below the ceiling. Inverted tee, "H and T," or "Z" profile grids are common for these applications with provisions for full plenum access usually incorporated into the grid design
Concrete	Concrete is a hardened building material created by combining a mineral (which is usually sand, gravel, or crushed stone) a binding agent (natural or synthetic cement), chemical additives, and water. It is an excellent material to be used in road building, bridges, airports, factories, waterways and other construction projects. Concrete is the mixture of Portland cement, sand, gravel, and water used to make garage and basement floors, sidewalks, patios, foundation walls, etc. It is commonly reinforced with steel rods (rebar) or wire screening (mesh).
Concrete block	A concrete masonry unit, most often hollow, that is larger than a brick.
Concrete finish	A description of the smoothness, texture, or hardness of a concrete surface. Floors are trowelled with steel blades to compress the surface into a dense protective coat.
Concrete Hardener	Compounds or other materials designed to strengthen the surface of new concrete and improve the quality of old concrete. These do not normally cause any bonding problems with resilient flooring installations, but a bond test should be run.
Concrete masonry unit (CMU)	A block of hardened concrete, with or without hollow cores, designed to be laid in the same manner as a brick or stone. A CMU is also referred to as a concrete block.
Concrete Sealer	Sealers are normally a finish coating used to protect concrete floors from traffic and surface cleaning and should not be used when the slab is intended as a substrate for resilient flooring. Sealers are designed to prevent water and dirt from getting into the concrete from the surface and render the concrete less porous. Sealers may interfere with the bond adhesives, and a bond test should always be run.
Condenser	The device in an air conditioner or heat pump in which the refrigerant condenses from a gas to a liquid when it is depressurized or cooled.
Condenser Coil	The device in an air conditioner or heat pump through which the refrigerant is circulated and releases heat to the surroundings when a fan blows outside air over the coils. This will return the hot vapor that entered the coil into a hot liquid upon exiting the coil.
Condensing Unit	The component of a central air conditioner that is designed to remove heat absorbed by the refrigerant and transfer it outside the conditioned space.
Conditioned Air	Air that has been heated, cooled, humidified, or dehumidified to maintain an interior space within the "comfort zone." (Sometimes referred to as "tempered" air.)
Conditioned Space	The interior space of a building that is heated or cooled.
Constant Air Volume Systems	Air handling system that provides a constant air flow while varying the temperature to meet heating and cooling needs.
Construction joint	The contact between the placed concrete and concrete surfaces, against or upon which concrete is to be placed and to which new concrete is to adhere, that has become so rigid that the new concrete cannot be incorporated integrally by vibration with that previously placed. Unformed construction joints are placed horizontally or nearly horizontally.
Control joint	Tooled, straight grooves made on concrete floors to "control" where the concrete should crack.
Control Joints	Are used to relieve stresses induced by expansion and contraction in large ceiling and wall expanses in drywall and veneer plaster systems
Controller	A device for regulating in a predetermined way the power delivered to the motor or other equipment.
Cooling Capacity	The quantity of heat that a cooling appliance is capable of removing from a room in one hour.
Coping	A cap or covering course on top of a masonry wall. Designed to shed water, protect the top, and provide a finished, closed appearance to the wall.
Course	A continuous layer of building units running horizontally in a wall.
Cove	A trim tile with one edge a concave radius. Used to form a junction between the bottom wall course and the floor or to form an inside corner.
Cove Base	Usually made of vinyl or rubber in a variety of sizes and shapes, cove base is designed to give a finished appearance between the floor and the wall. The base meets requirements of ASTM F 1861, Standard Specification for Resilient Wall Base.
CPVC (Chlorinated Polyvinyl Chloride)	Rigid plastic pipe used in water supply systems, where code permits.
Crane Girder	The principal horizontal beams of the crane bridge that supports the trolley and is supported by the end tracks.
Crane Rail	A track supporting and guiding the wheels of a top-running bridge crane or trolley system.
Crane Runway Beam	The member that supports a crane rail and is supported by columns or rafters depending on the type of crane system. On underhung bridge cranes, the runway beam also acts as the crane rail.
Crane Stop	A device to limit travel of a trolley or crane bridge. This device normally is attached to a fixed structure and normally does not have energy-absorbing ability.
Crane Support Column	A separate column that supports the runway beam of a top-running crane.
Cricket	A ridge or drainage diverting roof framing.
Curb and gutter	The border area of a street, or other paved surface, that includes a curb, an extruded or hand-formed berm, and a gutter, the area designed to remove and transport water away from the main paved area. Both parts are usually made out of concrete.
Curing	The hardening of concrete, plaster, or other wet material. Curing typically occurs through the evaporation of water or a solvent, hydration, polymerization, or chemical reactions of various types. It is the final process, after placing and compacting, that ensures the concrete will set to its desired strength. The length of time is dependent upon the type of cement, mix proportion, required strength, size and shape of the concrete section, weather and future exposure conditions. The period may be 3 weeks or longer for lean concrete mixtures used in structures such as dams or it may be only a few days for richer mixes. Favorable curing temperatures range from 50° to 70° F. Design strength is achieved in 28 days
Curing compound	A chemical applied to the surface of fresh concrete to minimize the loss of moisture during the first stages of setting and hardening
Cut and Fill	A term used to describe the addition or subtraction from a grade mark. An operation commonly used in which the material excavated from one location is used as fill at another location on the site.
D	Back To Top
Dampers	HVAC term for controls that vary airflow through an air outlet, inlet, or duct. A damper position may be immovable, manually adjustable or part of an automated control system.
Dampproofing	A process used on concrete, masonry or stone surfaces to repel water, the main purpose of which is to prevent the coated surface from absorbing rain water while still permitting moisture vapor to escape from the structure. (Moisture vapor readily penetrates coatings of this type.) "Dampproofing" generally applies to surfaces above grade; "waterproofing" generally applies to surfaces below grade.
Dead Load	Loads due to the weight of the components making up the structure and that are intended to remain permanently in place.
Deck Type	The specific type of deck to be specified, such as Type "B" Wide Rib, Type "F" Intermediate, Type "N" Deep Rib, Type "A" Narrow Rib, Composite, Cellular, etc.
Deflection	The displacement of a structural member or system under load.
Dehumidifier	A device for reducing the level of humidity in a room or home.
Demand (tankless) Water Heater	A type of water heater that has no storage tank thus eliminating storage tank stand-by losses. Cold water travels through a pipe into the unit, and either a gas burner or an electric element heats the water only when needed.
Detention basin (drypond)	An area made to collect storm water runoff from a management system for the purpose of reducing peak flow and controlling rate of flow. A retention basin can be defined as having a permanent pool, whereas, a detention basin is normally dry.
Device	As distinct from a fixture or appliance, an item which does not itself consume significant electricity, but interrupts or passes it on in a particular fashion. For example, a switch, a receptacle, a thermostat, a breaker, a fuse.
Diffusers and Grilles	Components of the ventilation system that distribute and return air to promote air circulation in the occupied space. As used in this document, supply air enters a space through a diffuser or vent and return air leaves a space through a grille.
Dimmer	Also rheostat. A switch able to dim its lights by altering the voltage it passes on. A dimmer normally gets warm when operating but will overheat if running more wattage than it is designed for.
Direct Water Heater	A type of water heater in which heated water is stored within the tank. Hot water is released from the top of the tank when a hot water faucet is turned. This water is replaced with cold water that flows into the tank and down to just above the bottom plate under which are the burners.
Dowel	A cylindrical piece of stock inserted into holes in adjacent pieces of material to align and/or attach the two pieces
Downspout	A conduit used to carry water from the gutter of a building.
Drums	Circular stamped metal parts attached at various locations along the tubular shaft that allows the sheet door curtain to coil up when the door is opened.
Dry pipe systems	Dry pipe systems are installed in spaces in which the ambient temperature may be cold enough to freeze the water in a wet pipe system, rendering the system inoperable. Dry pipe systems are most often used in unheated buildings, in parking garages, in outside canopies attached to heated buildings (in which a wet pipe system would be provided), or in refrigerated coolers. Dry pipe systems are the second most common sprinkler system type. In regions using NFPA regulations, dry pipe systems cannot be installed unless the range of ambient temperatures reaches below 40F.
Dry shake (dry topping)	A concrete surface treatment, such as color, hardening, or antiskid, which is applied to a concrete slab by shaking on a dry, granular material before the concrete has set and then troweling it in
Drywall	Also known as wallboard or gypsum board, a paper covered panel of compressed gypsum used as the primary wall covering in almost all interior walls.
Duct(s)	The round or rectangular tube(s), generally constructed of sheet metal, fiberglass board, or a flexible plastic-and-wire composite, located within a wall, floor, and ceiling that distributes heated or cooled air in buildings.
E	Back To Top
Eave	The line along the sidewall formed by the intersection of the planes of the roof and wall.
Eave Canopy	A projecting roof system on the sidewall whose overhanging edge is supported at the building.
Eave Height	The vertical distance from finished floor to the eave.
Effluent	Septic system liquid waste.
EIFS	Exterior Insulation and Finish Systems (EIFS) are a type of exterior cladding. They are multi-component systems which provide weather resistance, insulation, and the final colour and shape of the structure
elastomeric	Materials that are "elastomeric" could also be said to be "elastic". Both terms describe what most people would refer to as "rubberiness", or behaving like rubber (which stretches and compresses, and returns to its original shape instantly after stress is removed).
Electricity	A force generated onto loops of conductive material, transferred through their electrons, and applied as useful energy at parts of these loops.
End Approach	The minimum horizontal distance, parallel to the runway, between the outermost extremities of the crane and the centerline of the hook.
End Frame	A frame located at the endwall of a building that supports the loads from a portion of the end bay.
Endstop	A device to limit travel of a trolley or crane bridge. This device normally is attached to a fixed structure and normally does not have energy absorbing ability.
Epoxy grout	a two–part grout system consisting of epoxy resin and epoxy hardener. Made to have impervious qualities, stain and chemical resistant. Used to fill joints between tiles.
Erection	The process of installing joists, joist girders, beams, bridging, deck, or other structural members in order to construct a structure.
Escutcheon	A decorative metal flange or trim shield beneath a faucet handle that covers the faucet stem and the hole in the fixture or wall.
ESFR – Early Suppresion Fast Response	A type of fast-response sprinklers listed for its capability to provide fire suppression of high-challenge fire hazards
Excavation	A cavity formed by, or as if by, cutting, digging or scooping.
Exhaust Ventilation	HVAC term for mechanical removal of air from a portion of a building (e.g., piece of equipment, room, or general area).
Expansion Joint	A break in construction or a special design detail to allow for thermal expansion and contraction of the materials of a structure; A type of building joint where a significant distance is left between two substrates so as to accommodate normal building expansion and contraction due primarily to temperature changes. A sealant placed in this type of joint is subject to being stretched and compressed, rather than being sheared. (See "Lap Joint"); A break or space in construction to allow for thermal expansion and contraction of the materials used in the structure.
Expansion Tank	A tank designed to absorb excess pressure due to thermal expansion (e.g. closed system).
Exposed aggregate finish	A method of finishing concrete which washes the cement/sand mixture off the top layer of the aggregate - usually gravel. It is often used in driveways, patios and other exterior surfaces.
Exposed Grid System	Structural suspension system for lay-in ceiling panels. Factory-painted supporting members are exposed to view. Exposed tee surfaces may be continuous or have an integral reveal. Reveals are typically formed as channel or rail profiles extending down from the tee leg. Bolt-slot type reveal designs can accommodate partition attachment. The choice may be restricted by appropriate tee width for panel selected and limitations on available panel edge details for the chosen grid profile
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Fabrication	The manufacturing process to convert raw materials into a finished product by cutting, punching, welding, cleaning, and painting.
Face Weight	Face weight is the number of ounces of fiber per square yard in the face of the carpet (not including the backing). The face weight affects performance and durability. Face weight is different from density because it varies with carpet height
Fall/Flow	The proper slope or pitch of a pipe for adequate drainage
Fascia	The flat surface located at the outer end of a roof overhang or cantilever end or also a decorative trim or panel which projects from the face of a wall.
FDC	Fire Department Connection. An FDC is a connection outside of a building that connects to the discharge side of a fire pump system. In the case of fire pump or power failure the fire sprinkler system can be fed directly by a fire engine's pump system.
Fiber reinforced concrete	A variant of concrete that is produced by adding fibers made of stainless steel, glass or carbon to the mixture.
Fiberglass-Reinforced Plastic (FRP)	A tough, nonscuff plywood coating made of glass fibers combined with resins. These coated panels (composite) are used in wet-walls or high moisture areas.
Field tile	the primary tile used to cover a wall or floor
Filter (air)	A device that removes contaminants, by mechanical filtration, from the fresh air stream before the air enters the living space. Filters can be installed as part of a heating/cooling system through which air flows for the purpose of removing particulates before or after the air enters the mechanical components.
Fire Wall	Fire-resistant partition extending to or through the roof of a building to retard spread of fire.
Fixed Base	A column base that is designed to resist rotation as well as horizontal or vertical movement.
Fixed Clip	A standing seam roof system hold down clip that does not allow the roof panel to move independently of the roof substructure.
Fixture	Plumbing: the devices that provide a supply of water and/or its disposal, e.g. sinks, tubs, toilets; Lighting: Or "luminaire". A non-portable electrically-produced-light assembly. Distinguished from appliance or device.
Floating Clip	A standing seam roof system hold down clip that allows the roof panel to horizontally move independently of the roof substructure. Also known as a "Sliding Clip" or "Slip Clip".
Floor-Operated Crane	A crane that is pendant controlled by an operator on the floor or an independent platform
Flow Meter/Flow Meter Loop	A fire pump system piping configuration which allows for system testing without flowing waste water out of the system. A connection on the discharge side of the fire pump system routes water through a venturi (a flow meter) which measures the water flow, the water is then routed back to the suction side of the fire pump and circulated back through the system or back to a storage tank.
Fly ash	A byproduct produced by coal-burning power plants that contains aluminosilicate and small amounts of lime. When combined with lime in a hydrothermal (using hot water under pressure) process, cement can be produced. It is a concrete admixture
FMS (Factory Mutual System)	A leader in property loss prevention engineering and adjustment. It helps companies prevent and control property loss through research, engineering, and education.
Footing	The widened portion of the foundation or a structure that spreads and transmits the load from the building or foundation directly to, and across a broader area of, the soil. A continuous 8" or 10" thick concrete pad installed before that supports the foundation wall or monopost. The soils, gravel and/or engineered materials used directly below a retaining wall upon which its concrete units rest.
Foundation	The entire masonry substructure below the first floor or frame of a building, including the footing upon which the building rests.
Framed Opening	Framing members and flashing which surround an opening.
French Drain	A covered ditch containing a layer of fitted or loose stone or other pervious material.
Full Vertical Track Assembly	An assembly made up of a piece of vertical track and a piece of continuous angle or jamb brackets which is used to secure the track to the jamb.
Fuse	A device that interrupts current to its circuit by melting apart. It must then be replaced.
Fusebox	Like a panel, a usual main source of the circuits in a home. It contains fuses rather than breakers.
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Gable	The triangular portion of a roof located above the elevation of the eave line of a double sloped roof.
Galvanized	The process of coating steel with zinc for corrosion resistance.
Gang	A combining of more than one device side-by-side, as, a "three-gang" switch box.
Gantry Crane	A crane similar to an overhead crane except that the bridge for carrying the trolley or trolleys is rigidly supported on one or more legs running on fixed rails or other run-way.
Geotextile	A woven or non-woven thermoplastic sheet material intended to allow the passage of water, but not fines, and without collecting fines at the soil-textile interface.
GFI or GFCI	A ground-fault interrupter. A device to prevent electrocution, which serves also as a receptacle or (less commonly) as a breaker. I consider the letters "GFCI" confusing because they stand for "ground-fault circuit interrupter" and the word "circuit" is vague and distracting. "GFI" clearly states the function it performs "ground-fault interrupter".
Girder	A main horizontal, or near horizontal, primary structural member spanning between two main supports which carries other members or vertical loads. It may consist of several pieces.
Girders (crane)	The principle horizontal beams of the crane bridge, which supports the trolley, and are supported by the end trucks
Girt	A horizontal structural member that is attached to the sidewall or endwall columns supporting sheeting or paneling.
Glass Fiber Reinforced Concrete (GFRC)	Material used in wall systems that resembles but generally does not perform as well as concrete. It usually is a thin cementitious material laminated to plywood or other lightweight backing.
Glazed Opening	Any opening in a door or wall that contains glass
Glazed tile	a tile that has an impervious facial finish composed of gaseous ceramic materials fused to the surface of the tile.
Grade	The surface or level of the ground. The existing or proposed ground level or elevation on a building site or around a building. The slope or rate of incline or decline of a road, expressed as a percent. A designation of a subfloor, either above grade, on grade, or below grade. Any surface prepared to accept paving, conduit, or rails
Grade, finished	The completed surfaces of lawns, walks and roads brought to grades as designed.
Grade, natural	The undisturbed natural surface of the ground.
Grade, subgrade	The grade established in preparation for top surfacing of roads, lawns, etc.
Gradient	The degree of inclination of a surface, road or pipe, usually expressed as a percentage.
Granite	a natural stone more dense than marble. Granite is molten lava that never rose above the surface of the earth. It is extremely durable and holds a polish. Available in polished, honed or flamed (rough) surfaces.
Gray Water	Waste water from sinks, showers, and bathtubs, but not toilets.
Ground	The common reference point for the voltage of a home’s electrical system. It refers to an intended or unintended connectedness to the earth. The neutral wires of circuits and of the system are grounded, but a "ground wire" means a separate "grounding" wire keeping metal parts of devices, fixtures, or appliances from staying accidentally energized and endangering people or equipment. Installed in homes since the 1960’s, these wires are to be either bare or green-covered. The ground wire is not connected so as to be part of the normal path of the circuit, as a neutral is. When a ground wire does carry current, it is taking care of an otherwise dangerous situation; in fact, it is supposed to carry so much flow suddenly, that it causes the breaker of the circuit to trip, thereby also alerting us that a problem needs attention. If things were not grounded, people’s bodies would more often be a path for current from a hot wire touching the metal to get to ground (without our having enough conductivity to trip a normal breaker!).
Ground-fault	Any short circuit finding at least some of its path to the earth by way of something other than the neutral wire. It is a "leaking" of current off of the intended path. Most shocks are an example.
Groundwater	Water beneath the surface of the earth which saturates the pores and fractures of sand, gravel and rock formations.
Grout	Mortar with a high water ratio, composed of silica sand, cement and chemical mix, used to fill open joints between installed stone or building units. Normally, grout is worked into these joints with a hard rubber float. Available in a wide variety of colors.
Guide Rails	Steel T-, round, or formed sections with guiding surfaces installed vertically in a hoistway to guide and direct the course of travel of an elevator car and elevator counterweights
Gutter	A light gauge metal member at an eave, valley or parapet designed to carry water from the roof to downspouts or drains.
Gypsum	A soft mineral used to make walls, sheetrock.
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Haunch	The deepened portion of a column or rafter designed to accommodate the higher bending moments at such points. (Usually occurs at the intersection of the column and the rafter.)
Header	The main horizontal member of the frame, forming the top of the window, transom or door frame.
Heat Loss	The heat that flows from the building interior, through the building envelope to the outside environment.
Hip	The line formed at the intersection of two adjacent sloping planes of a roof.
Hip and Valley	A system of roof framing where support members form valleys and ridges.
Hip Roof	A roof which slopes from all four sides of a building. The line where two adjacent sloping sides intersect is called the 'hip'.
Hoist	A machinery unit that is used for lifting and lowering a load.
Holding Brake	Elevators: A brake that automatically prevents motion when power is off.
Hook Approach	The minimum horizontal distance between the center of the runway rail and the hook.
Hose Bibb	An outdoor faucet, also used to supply washing machines.
Hot-Rolled Shapes	Structural steel sections which are formed by rolling mills from molten steel which can be angles, channels, W Shapes, S Shapes, etc.
Humidity	A measure of the moisture content of air; may be expressed as absolute, mixing ratio, saturation deficit, relative, or specific.
HVAC	HVAC is an acronym for heating, ventilation, and air-conditioning system.
Hydraulic	One of two methods by which an elevator is moved, whereby the elevator is "pushed" up by oil.
Hydraulic Brake	A brake that provides retarding or stopping motion by hydraulic means.
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IAQ	Indoor air quality.
Industrial Duity Crane	Service classification covered by CMAA Specification No. 70 and Specification No. 74, 'Specifications for Electric Overhead Traveling Cranes'
Infiltration	Air leakage inward through cracks and interstices and through cielings, floors, and walls of a space or building.
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Jack	The device which pushes the hydraulic elevator.
Jack Beam	A beam used to support another beam, rafter or truss and eliminate a column support.
Jamb	The main vertical members forming the sides of a window or door frame.
Jamb Seal	Weather-stripping attached to the door jamb to provide a seal along the jambs.
Jib Crane	A cantilevered or suspended beam with hoist and trolley. This lifting device may pick up loads in all or part of a circle around the column to which it is attached.
Jockey/Booster Pump	An auxiliary pump used to maintain system pressure without starting the main pump. These pumps are not designed to keep up with full system demand, their only function is system pressure maintenance.
Joint	Position where two or more building materials, components or assemblies are put together, fixed or united, with or without the use of extra jointing products. The location between the touching surfaces of two members or components joined and held together by nails, glue, cement, mortar, or other means.
Joist	A structural load-carrying member with an open web system which supports floors and roofs utilizing hot-rolled or cold-formed steel and is designed as a simple span member.
Junction box	As distinguished from any electrical box, a box used only for making connections, not for also supporting a switch, receptacle, or light. The boxes for these others usually also have connections and splices in them in addition.
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Keyway	A recess or groove in one lift or placement of concrete that is filled with concrete of the next lift, giving shear strength to the joint. Also called a key.
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Laminate	Family of products in which a finish material is fused to a substrate. Laminates include LPL (Low-Pressure Laminate) and HPL (High-Pressure Laminate). HPL is thicker, stronger and more durable.
Lavatory (Lav)	A fixed bowl or basin with running water and drainage for washing. Also reffered to as a restroom or a bathroom.
LEED™	Leadership in Energy and Environmental Design. A sustainable design building rating system promulgated by the United States Green Building Council. Also an accrediting program for professionals (LEED APs) who have mastered the certification system. www.usgbc.org
LIFT	Maximum safe vertical distance through which the hook, magnet, or bucket can move.
Lift Clearance	Refers to track hardware that causes the door to rise vertically some distance before it levels out into a horizontal position. Also known as High Lift Track, Lift-Clearance is the distance above the top of door opening to the underside of horizontal tracks. (Commercial door application)
Light Transmitting Panel	Panel used to admit light.
Limestone	sedimentary stone that could have fossils or shells. Usually comes with a honed (matte) finish. Not a wide variety of color; stones have little variety from piece to piece.
Limit Switch	A device designed to cut off the power automatically at or near the limit of travel for the crane motion.
Liner Panel	A metal panel attached to the inside flange of the girts or inside of a wall panel.
Live Load	Loads that are produced (1) during maintenance by workers, equipment, and materials, and (2) during the life of the structure by movable objects and do not include wind, snow, seismic, or dead loads. Also see Roof or Floor Live Load.
Longitudinal	The direction parallel to the ridge or sidewall.
Longitudinal (Crane)	Direction parallel to the crane runway beams.
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Machine Room	The space in which the driving machine for an elevator or group of elevators, dumbwaiter, escalator or group of escalators is located
Main Frame	An assemblage of rafters and columns that support the secondary framing members and transfer loads directly to the foundation.
Marble	a natural stone product quarried from the earth. It gets a distinctive shine from the polishing process it goes through. Available in multiple finishes and a wide variety of colors.
Masonry	Construction composed of shaped or molded units, usually small enough to be handled by one man and composed of stone, ceramic brick, or tile, concrete, glass, adobe, or the like. The term masonry is sometimes used to designate cast-in-place concrete.
Masonry cement	A mill-mixed mortar to which sand and water must be added. A Portland cement with dry admixtures designed to increase the workability of the mortar
Mechanical Load Brke	An automatic type of friction brake used for controlling loads in the lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose additional load on the motor when lifting a load.
Metal Building System	A complete integrated set of mutually dependent components and assemblies that form a building including primary and secondary framing, covering and accessories, and are manufactured to permit inspection on site prior to assembly or erection.
Mezzanine	An intermediate level between floor and ceiling occupying a partial area of the floor space.
Mill Duty Crane	Service classification covered by AISE Standard No. 6, ‘Specification for Electric Overhead Traveling Cranes for Steel Mill Services’,
Mix	A general term referring to the combined ingredients of concrete or mortar. Examples might be a five-bag mix, a lean mix, or a 3,000-psi mix
Moment Connection	A connection designed to transfer moment as well as axial and shear forces between connecting members.
Monolithic Pour	The placing of concrete in a monolithic construction.
Mortar Bed	A troweled layer of mortar, in a plastic state, in which building units will be set.
Mortise	Machining and reinforcing a preparation into door or frame for attachment of hardware. With our frame we do not machine our preparations, we use a process called embossing.
Mud slab	A base slab of low-strength concrete from 2" to 6" thick placed over a wet subbase before placing a concrete footing or grade slab
Mullion	A slender dividing bar between two doors. Usually designed to carry horizontal (wind) load but not vertical load. (Commercial door application)
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Natural Ventilation	In HVAC the movement of outdoor air into a space through intentionally provided openings, such as windows and doors, or through nonpowered ventilatiors or by infiltration.
Negative Pressure	Condition that exists when less air is supplied to a space than is exhausted from the space, so the air pressure within that space is less than that in surrounding areas. Under this condition, if an opening exists, air will flow from surrounding areas into the negatively pressurized space.
Neutral	The wires of a circuit connected ultimately to the earth to receive flow "back" from a light or appliance. They are always supposed to be white. Contact with them should not normally shock you because they are normally connected to ground much better than you can be.
NFPA-13R	The standard for the installation of sprinkler systems in residential occupancies up to and including four stories in height. Covers the design and installation of automatic sprinkler systems for protection against fire hazards.
NFPA-20	The standard for the installation of stationary pumps for fire protection. Deals with the selection and installation of pumps supplying liquid for private fire protection including liquid supplies; suction, discharge, and auxiliary equipment; power supplies, including power supply arrangements; electric drive and control; diesel engine drive and control; steam turbine drive and control; and acceptance tests and operation.
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Offset Ridge	When the ridge of a joist that has the top chord pitched two ways is not in the center of the member or bay.
Oil Canning	A waviness that may occur in flat areas of light gauge formed metal products. Structural integrity is not normally affected by this inherent characteristic; therefore oil canning is only an aesthetic issue. Oil canning is not a cause for rejection of the material.
Outdoor Air	Air taken from the external atmosphere and, therefore, not previously circulated through the system.
Outdoor Air Supply	HVAC term for air brought into a building from the outdoors (often through the ventilation system) that has not been previously circulated through the system. Also known as "Make-Up Air".
Outlet	Technically, any point along a circuit where a light or appliance receives its final connections to the hot and neutral of the circuit. The outlet may consist of a receptacle for a cord to plug into, or it may be a box at which the item using the electricity is "hard-wired". In practice, however, we usually mean a receptacle. The following are not outlets: switch, breaker, junction box.
Overload	Any load greater than the rated load.
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Panel	Or "panel box" or "breaker box". The large metal box containing breakers for circuits. The "main" panel or "service" panel would be the central source for the facility and would be receiving its power from the power company. There can be subpanels in a home, fed from the main panel and containing some of the facilities circuit breakers
Panel Notch	A notch or block out formed along the outside edge of the floor slab to provide support for the wall panels and serve as a closure along their bottom edge.
Parapet	The portion of a vertical wall of a building which extends above the roof line at the intersection of the wall and roof.
Paver, paving	Materials, typically masonry, that are laid down to make a firm, even surface.
Peak	The uppermost point of a gable.
Pendant Pushbutton Station	Means suspended from the crane operating the controllers from the floor or other level beneath the crane.
Penthouse	The machine room above the hoistway on traction elevators.
Perimeter Seal	Complete weather-stripping package for sectional doors, consisting of astragral, jamb seal and header seal.
Perimeter Weatherstrip	Vinyl or felt attached to corrugated sheet door curtain to prevent rubbing. Located at the ends or drum locations.
Permeability	A generic term for the property that reflects the ability of a material to conduct a fluid or vapor through a porous media such as soil or geotextiles. Properly called hydraulic conductivity.
Personnel Doors	doors used by personnel for access and exit from a building.
Pervious	The property of a material which permits movement of water through it under ordinary hydrostatic pressure.
Pier	A concrete structure designed to transfer vertical load from the base of a column to the footing.
Pilaster	A reinforced or enlarged portion of a masonry wall to provide support for vertical roof loads or lateral loads on the wall.
Pinned Base	A column base that is designed to resist horizontal and vertical movement, but not rotation.
Placing	The physical insertion of the concrete mixture into the final location avoiding segregation of the mixture materials and compaction can be achieved. The deposition, distribution, and consolidation of freshly mixed concrete in the place where it is to harden. Also, inappropriately referred to as pouring
Plasticizer	An agent used to increase the fluidity of fresh cement with the same cement/water ratio improving the workability and placement of the cement. Same as a superplasticizer
Plenum	The ceiling plenum is the volume defined by the area above the back of the ceiling tile, and below the bottom of the structural slab above. Within this plenum is usually found a combination of HVAC ducts, electrical and electronic conduits, water pipes, traditional masking sound speakers, etc. HVAC term for an air compartment connected to a duct or ducts.
Plumbing Tree	Prefabricated set of drain waste, vent, and supply lines.
Porcelain tile	Characterized by a dense and impervious body generally made of the dust–pressed method.
Portal Frame	A rigid frame so designed that it offers rigidity and stability in its plane. It is generally used to resist longitudinal loads where other bracing methods are not permitted.
Portland cement	A special synthetic blend of limestone and clay used to make concrete which is generally believed to be stronger, more durable, and more consistent than concrete made from natural cement. Portland cement is made by mixing calcareous material, like limestone, with silica, alumina, and iron oxide-containing materials. These materials are burned together and the resulting product, or admixture, is ground up to form Portland cement
Position Indicator	A device that indicates the position of the elevator car in the hoistway. It is called a hall position indicator when placed at a landing, or car position indicator when placed in the car.
Positive Pressure	Condition that exists when more air is supplied to a space than is exhausted, so the air pressure within that space is greater than that in surrounding areas. Under this condition, if an opening exists, air will flow from the positively pressurized space into surrounding areas.
Post and Beam	A structural system consisting of a series of rafter beams supported by columns. Often used as the end frame of a building.
Post-tensioning	A method of pre-stressing reinforced concrete in which tendons are tensioned after the concrete has hardened
Pre-cast concrete	Concrete forms cast into permanent shapes using reusable forms at a plant, then transported as fully cured structural units to the actual construction job site
Precast concrete retaining wall	Gravity or semi-gravity retaining walls composed of prefabricated concrete modules with or without fill material placed within these elements.
Pressure Tank	Device used to pump water from a well.
Preventative Maintenance	Regular and systematic inspection, cleaning, and replacement of worn parts, materials, and systems. Preventive maintenance helps to prevent parts, material, and systems failure by ensuring that parts, materials and systems are in good working order.
ProgrammableThermostat	A type of thermostat that allows the user to program into the devices' memory a pre-set schedule of times (when certain temperatures occur) to turn on HVAC equipment.
Purlin	A horizontal structural member that supports roof covering and carries loads to the primary framing members. Usually cold-formed, attached perpendicular to the joist top chord or main frames ofa building for suppot of the roof deck.
PVC (Polyvinyl Chloride)	A rigid white or cream-colored plastic pipe used in non-pressure systems, such as drainage, waste, and vent systems.
PVC pipe	A type of smooth wall thermoplastic pipe manufactured using Polyvinyl Chloride, which is widely accepted for drainage applications due to its cost, longevity and chemical resistance.
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R-Value	A measure of the capacity of a material to resist heat transfer. The R-Value is the reciprocal of the conductivity of a material (U-Value). The larger the R-Value of a material, the greater its insulating properties.
R-Value (Thermal Resistance)	Ability of a material to retard the transmission of heat. The higher the R-value, the better the insulating performance.
Radiant Barrier	In HVAC a thin, reflective foil sheet that exhibits low radiant energy transmission and under certain conditions can block radiant heat transfer; installed in attics to reduce heat flow through a roof assembly into the living space.
Rafter	The main beam supporting the roof system.
Rake	The intersection of the plane of the roof and the plane of the endwall.
Rated Load	The maximum load which the crane is designed to handle safely as designated by the manufacturer.
Reactions	The resisting forces at the column bases provided by foundations that hold a structure in equilibrium under a given loading condition.
Ready-mixed concrete	Concrete that is batched or mixed at a central plant before it is delivered to a construction site and delivered ready for placement. It is also known as transit-mixed concrete since it is often transported in an agitator truck. See agitator truck.
Rebar	The reinforcing bar-ribbed steel bars installed in foundation concrete walls, footers, and poured in place concrete structures designed to strengthen concrete. Rebar comes in various thickness' and strength grade. The term rebar is short for reinforcing bar.
Receptacle	Also "plug-in"; or, loosely, "outlet" or "plug". A device that serves as the outlet for lights or appliances to connect to a circuit by means of a cord with a "plug" on the end.
Recirculated Air	Air removed from the conditioned space and used for ventilation, heating, cooling, humidification, or dehumidification.
Refrigerant	The compound (working fluid) used in air conditioners, heat pumps, and refrigerators to transfer heat into or out of an interior space. This fluid boils at a very low temperature enabling it to evaporate and absorb heat.
Regrading	Earthwork construction to level or smooth the existing ground surface to a desired or horizontal grade.
Reinforced concrete	Concrete reinforced by the addition of steel bars making it more able to tolerate tension and stress
Reinforced fill	Retaining wall backfill that contains reinforcing material to create the structure. Used in engineered applications.
Reinforcement.	Improvement of the system strength created by the introduction of a geosynthetic into a soil/aggregate system
Relative Humidity	A measure of the percent of moisture actually in the air compared with what would be in it if it were fully saturated at that temperature. When the air is fully saturated, its relative humidity is 100 percent.
Remote Radio Control	A cordless means of control, utilizing analytical or digital radio signals to secure controls even in noisy environments
Retaining wall	A wall built to hold back earth allowing adjacent areas to be at different elevations. Wall inclinations are typically 70 to 90 degrees with respect to the horizontal.
Retention basin	An area made to collect storm water runoff from a management system for the purpose of reducing peak flow and controlling rate of flow. A retention basin can be defined as having a permanent pool, whereas, a detention basin is normally dry.
Return Air	Air that is returned to a heating or cooling appliance from a heated or cooled space.
Return Duct	The central heating or cooling system contains a fan that gets its air supply through these ducts, which ideally should be installed in every room of the house. The air from a room will move towards the lower pressure of the return duct
Rib	The longitudinal raised profile of a panel that provides much of the panel's bending strength.
Ridge	The highest point on the roof of a building formed by two intersecting slopes or the horizontal line made by the top surfaces of the two intersecting sloping roof surfaces.
Rigid Frame or Structure	A structural framing system consisting of members joined together with moment or rigid connections which maintain their original angular relationship under load without the need for bracing in its plane.
Riprap	Stones or other material placed on a slope or in a channel to prevent erosion by water.
Riser	A vertical metal or plastic tube or assembly that connects a faucet to the water supply stop valve. Usually made of copper. Metal Flex Risers are corrugated to facilitate bending. Also a supply line that rises from one story to the next.
Roll-Up Door	A door that opens by traveling vertically and is gathered into a roll suspended some distance above the floor.
Rolling Doors	Doors that are supported at the bottom on wheels that run on a track.
Roof Covering	The exposed exterior roof skin of a building which can be sheets, panels or other materials.
Runoff	The part of precipitation that flows off the area on which it falls.
Runway	The rails, beams, brackets and framework on which the crane operates.
Runway Conductors	The main conductors mounted on or parallel to the runway, which supplies current to the crane.
Runway Rail	The rail supported by the runway beams on which the bridge travels.
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Sack mix	The amount of Portland cement in a cubic yard of concrete mix. Generally, 5 or 6 sacks is required in a foundation
Sample	A portion of material, which is taken for testing or for recorded purposes and used in the laboratory as a source of individual specimens.
Sanitary Sewer	House drain that carries wastewater away from the house to a sewer system or septic tank.
Screed	To level off concrete to the correct elevation during a concrete pour. To strike off concrete lying above the desired plane or shape. A screed is also a tool for striking off the concrete surface, sometimes referred to as a strike off
Screw Down Roof System	A screw down roof system is one in which the roof panels are attached directly to the roof substructure with fasteners that penetrate through the roof sheets and into the substructure.
Scupper	Any opening or drain in the side of a structure, flat roof, or downspout for the drainage of rain water.
Seasonal Energy Efficiency Ratio (SEER)	A measure of seasonal or annual efficiency of a central air conditioner or air conditioning heat pump. It takes into account the variations in temperature that can occur within a season and is the average number of Btu of cooling delivered for every watt-hour of electricity used by the heat pump over a cooling season.
Secondary Framing	Members that carry loads from the building surface to the main framing. For example - purlins and girts.
Sectional Type Doors	Doors made of two or more horizontal sections hinged together to provide a door large enough to close the entire opening. Sectional doors are guided into the horizontal or open position by a system of vertical or horizontal tracks. May be fabricated of continuous roll-formed steel with reinforcing ribs, flush sections of steel or aluminum.
Select Fill	New soil material imported onto the site that meets the design requirements as defined by the civil or structural engineer.
Settlement	Sinking of solid particles in grout, mortar, or fresh concrete, after placement and before initial set.
Shake-on hardener	A dry powder that is dusted onto the surface of a concrete slab before troweling to react with the concrete and produce a hard-wearing surface for industrial uses. See troweling.
Shear Wall	A wall that resists horizontal shear forces applied in the plane of the wall.
Shop Primer Paint	The initial coat of primer paint applied in the shop. A temporary coating designed to protect the steel during shipping and erection until the building exterior and interior finish coverings have been installed. This coating may or may not serve as a proper prime coat for other finishing paints.
Shrinkage	A volume decrease caused by drying and/or chemical changes, such as of concrete or wood.
Side Wall	An exterior wall which is parallel to the ridge of the building.
Sidelite	A glazed area that is connected to a door opening.
Simple or Single Span	A span with supports at each end, no intermediate support, that restrain only against vertical displacement with the ends of the member being free to rotate.
Single Swing Frame	Frame prepared for one swing door.
Single-Ply Roof	A type of roofing system using thermoplastic membranes which are seamed by either hot air or solvent welding of one sheet to the next or using thermoset membranes which are seamed with an adhesive.
Sitecast concrete	Concrete that is poured and cured in its final position at a construction project. See pre-cast concrete and ready-mixed concrete.
Slab on grade	A type of foundation with a concrete floor that is placed directly on the soil. The edge of the slab is usually thicker and acts as the footing for the walls.
Slab, concrete	Concrete pavement that would be found in driveways, garages, and basement floors.
Slate	a natural material that is known for its dynamic colors and "earthy" appeal. Colors range from grey to purple to black. Slate is used outside as well as inside because of its natural look and wonderful colors.
Sleeve(s)	Pipe installed under the concrete driveway or sidewalk, and that will be used later to run sprinkler pipe or low voltage wire.
Slope	The angle or inclination a structural member makes with reference to a horizontal position expressed in inches of vertical rise per 12 inches of horizontal run, i.e. 3/12.
Slurry	A mixture of water and any finely divided insoluble material, such as Portland cement, slag, or clay in suspension
Soil stabilization	The act of improving soil properties by the inclusion of reinforcing elements such as geosynthetics, chemical substances, compaction or other methods.
Soldier Column	An intermediate column used to support secondary structural members; not part of a main frame or beam and column system.
Span	The distance between supports which is the centerline of a beam, column, or joist girder or 4 inches onto a wall.
Spandrel Joist or Beam	A structural member at the outside wall of a building, supporting part of the floor or roof and possibly the wall above.
Specific Humidity	The weight of water vapor, per unit weight of dry air.
Splice	An unanchored electrical connector joining two or more wires directly. Compare "Terminal".
Split System Air Conditioner	HVAC term for an air conditioning system that comes in two to five pieces: one piece contains the compressor, condenser, and a fan; the others have an evaporator and a fan. The condenser, installed outside the house, connects to several evaporators, one in each room to be cooled, mounted inside the house. Each evaporator is individually controlled, allowing different rooms or zones to be cooled to varying degrees.
Sprinkler Head	A metered nozzle designed to deliver a diffused spray of water at a certain flow rate (in gallons per minute) to cover a certain square-footage depending on pressure.
Sprinkler System Demand	The amount of water flow at a certain pressure required by the sprinkler heads for a certain amount of time. The flow and pressure components determine the fire pump and motor requirements, the time component determines water storage tank sizing (if a tank is necessary). NFPA-13D sprinkler demand is calculated by the water required to run two sprinkler heads simultaneously for 10 minutes. NFPA-13R sprinkler demand is calculated by the water required to run four sprinkler heads for thirty minutes.
Standing Seam	Side joints of roof panels that are arranged in a vertical position above the roofline.
Standing Seam Roof System	A roof system in which the side laps between the roof panels are arranged in a vertical position above the roofline. The roof panel system is secured to the roof substructure by means of concealed hold down clips attached with screws to the substructure, except that through fasteners may be used at limited locations such as at ends of panels and at roof penetrations.
Storage Water Heater	A water heater that releases hot water from the top of the tank when a hot water tap is opened. To replace that hot water, cold water enters the bottom of the tank to ensure a full tank.
Stud	An upright light gauge “Cee” shaped wall framing member.
Subgrade	The grade established in preparation for top surfacing of roads, lawns, etc.
Sump	A pit or pool for draining, collecting, or storing water. A chamber which provides water to the pump.
Super flat floor	A concrete slab finished to a high degree of flatness according to recognized systems of measurement.
Supply Duct	HVAC term for the duct(s) of a forced air heating/cooling system through which heated or cooled air is supplied to rooms by the action of the fan of the central heating or cooling unit.
Suspension System	A metal grid suspended from hanger rods or wires, consisting of main beams and cross tees, clips, splines and other hardware which supports lay-in acoustical panels or tiles. The completed ceiling forms a barrier to sound, heat, and fire. It also absorbs in-room sound and hides ductwork and wiring in the plenum.
Swale	A constructed or natural drainage channel used to direct surface flow. Constructed swales typically have parabolic, trapezoidal or triangular cross sections.
Switch	A device used to interrupt continuity and current to part of a circuit.
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Tankless Water Heater	A water heater that heats water before it is directly distributed for end use as required; a demand water heater.
Tegular	A functional edge detail. Tegular suspended ceiling panels have a rabbeted/reveal edge design that allows them to extend below the supporting grid, making the grid less conspicuous.
Temperature Zones	In HVAC individual rooms or zones in a building where temperature is controlled separately from other rooms or zones.
Tensile strength	Maximum unit stress which a material is capable of resisting under axial tensile loading, based on the cross sectional area of the specimen before loading.
Terminal	A screw or other pressure-device to which one or more wires are connected for passing electrical continuity and current along. Like a "Splice", but a terminal is anchored to a larger structure, whereas a splice is "free floating".
Texture	A decorative treatment of gypsum board surfaces.
Therm	A unit of heat containing 100,000 British thermal units(BTU).
Thermal Block	A spacer of low thermal conductance material that is installed between the purlin and roof insulation, to prevent energy loss.
Thin–set	term used to describe the bond coat in a thin bed installation. It is made of sand, cement and usually a latex additive.
Three-way	Although there is a type of light bulb and socket by this name, here we mean a switching system in which a light(s) is controllable from more than one location by two or more switches. The name comes from the usual number of terminals on or contact points within the switches involved.
Through-Fastened Roof System	A roof system in which the roof panels are attached directly to the roof substructure with fasteners, that penetrate through the roof sheets and into the substructure.
Tile	a ceramic unit, usually thin in relation to facial area. Made from clay or a mixture of clay and other ceramic material. Has a glazed or an unglazed face.
Tilt-up construction	A method of constructing concrete walls in which the wall panels are cast and cured flat on the floor slab or surrounding area and then tilted up into their final wall positions.
Tilt-up forms	Forms used in tilt-up construction. Forms that are placed on the ground and a flat horizontal slab is poured. When the slab is dry it is picked up with heavy equipment and lifted into place as a vertical wall.
Ton (Air Conditioning)	A unit of air cooling capacity; 12,000 Btu per hour.
Transom	A frame area immediately above a door opening and containing fixed glass, an operating sash, panel or other filler.
Transverse	The direction parallel to the main frames.
Travertine	similar composition to limestone but with holes created by hot springs. Colors include beige, red, yellow and brown, with some variation from piece to piece.
Tributary Area	The area directly supported by the structural member between contiguous supports.
TROLLEY	The unit carrying the hoisting mechanism which travels on the bridge rails
Trowel finish	The smooth finish surface produced by troweling
Type I Normal Cement	is a general purpose cement suitable for practically all uses in residential construction but should not be used where it will be in contact with high sulfate soils or be subject to excessive temperatures during curing.
Type II Moderate Cement	is used where precaution against moderate sulfate attack is important, as in drainage structures where sulfate concentrations in groundwater's are higher than normal.
Type III High Early Strength Cement	is used when high strengths are desired at very early periods, usually a week or less. It is used when it is desirable to remove forms as soon as possible or to put the concrete into service quickly.
Type IV Low Heat Cement	is a special cement for use where the amount and rate of heat generated during curing must be kept to a minimum. The development of strength is slow and is intended in large masses of concrete such as dams.
Type V Sulfate Resisting Cement	is a special cement intended for use only in construction exposed to severe sulfate action, such as western states having soils of high alkali content.
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Unit Ventilator	HVAC term for a fan-coil unit package device for applications in which the use of outdoor- and return-air mixing is intended to satisfy tempering requirements and ventilation needs.
Unreinforced concrete	Concrete made without steel reinforcing bars
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Vacuum Breaker	An anti-siphon device that prevents the backflow of contaminated water into the water supply system.
Valley	The angle formed by two sloping sides of a roof.
Vapor Barrier	A 6 mil or 10 mil plastic sheeting often used under slabs to control moisture penetrating from the subgrade.
Variable Air Volume System (VAV)	Air handling system that conditions the air to constant temperature and varies the outside airflow to ensure thermal comfort.
VARIABLE FREQUENCY	A method of control by which the motor supply frequency can be adjusted.
Vent	A component of a heating or ventilation appliance used to conduct fresh air into, or waste air or combustion gases out of, an appliance or interior space.
Vent Damper	HVAC term for a device mounted in the vent connector that closes the vent when the heating unit is not firing. This traps heat inside the heating system and house rather than letting it draft up and out the vent system.
Vent Pipe	A tube in which combustion gases from a combustion appliance are vented out of the appliance to the outdoors.
Vent Stack	Upper portion of the soil stack above the topmost fixture through which gases and odors escape
Ventilation	The process of moving air (changing) into and out of an interior space either by natural or mechanically induced (forced) means.
Ventilation Air	Defined as the total air, which is a combination of the air brought inside from outdoors and the air that is being re-circulated within the building. Sometimes, however, used in reference only to the air brought into the system from the outdoors; this document defines this air as "outdoor air ventilation."
Vermiculite	An aggregate somewhat similar to perlite that is used as an aggregate in lightweight roof decks and deck fills. It is formed from mica, a hydrous silicate with the ability 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.
Vertical Lift	A hardware design that allows a sectional door to open vertically along the wall above the door opening without turning back inside the building.
Voltage	The forcefulness with which electricity is ready to flow; also, the measurable relation of this force between two points ("volts"). Voltage can be present or fail to be present, and this is not identical with whether current is flowing or not. The relation is current cannot flow if voltage is lacking, but even with voltage available, current will only flow if a continuous and somewhat conductive path is provided. Mathematically voltage is the "product" of current (amps) and resistance (ohms), but in practice current is the product, that is, the result, of a provided voltage acting on a given resistance.
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W Shapes	A hot rolled shape called a Wide Flange Shape with symbol W which has essentially parallel flange surfaces.
Wall tile	glazed tile with a body suitable for interior use. Not expected to withstand excessive impact or be subject to freezing/thawing conditions. It is not appropriate for use on a floor.
Waste & Overflow	Drain assembly for a bathtub. The outlet at the top removes the overflow water during tub filling and the drain at the bottom removes wastewater when the tub is drained.
Water Storage Tank	A tank for storing water for fire protection systems. Normally required for residential systems due to flow limitations inherent in standard utility company water meters.
Water table	The location of the underground water. Also, the vertical distance from the surface of the earth to this underground water. The upper limit of water in saturated soil or underlying material.
Water-cement ratio	A numerical index of the relative proportions of water and cement in a concrete mixture. The ratio of the amount of water, exclusive only of that absorbed by the aggregates, to the amount of cement in a concrete or mortar mixture. The ratio is preferably stated as a decimal by weight. For example, the ratio 1:2:4 refers to a mix which consists of 1 cubic foot of cement, 2 cubic feet of sand and 4 cubic feet of gravel. Cement and water are the two chemically active elements in concrete and when combined, form a paste or glue which coats and surrounds the particles of aggregate and upon hardening binds the entire mass together
Watershed	The region or area contributing to the supply of a stream or lake.
Wattage	Rate of electric energy used by lights or appliances. When applied to devices, it indicates the maximum watts the device is designed to deliver or control (rather than use). Wattage is directly proportional to current and to voltage and is mathematically the product of them (amps times volts). 120 volts driving 15 amps through a resistance means 1800 watts is being used.
Wheel Load, Bridge	The vertical force (without impact) produced on any bridge wheel by the sum of the rated load, trolley weight, and bridge weight, with the trolley so positioned on the bridge as to give maximum loading.
Wheel Load, Trolley	The vertical force (without impact) produced on any trolley wheel by the sum of the rated load and the trolley weight.
Wheelbase	Distance from center-to-center of outermost wheels.
Window Sill	The bottom section of a window frame and/or the bottom section of an exterior masonry window opening.
Wire	A wire is bendable metal for carrying electric current. Except when used as a grounding wire, it is coated with insulative material. In homes, wires that run to outlet and switch locations are mostly within cables; their sizes (gauges "AWG") are (from smallest) 14, 12, 10, 8, 6, 4, etc., with larger wires at the meter and panel using a different numbering system. To understand the function that different wires on a circuit play, see Hot or Neutral or Ground above, or see Background. The functioning of each of these wires is not assured if they were not installed correctly or if they come apart at a connection or if they touch each other unintentionally. And it is not just the hot wire’s connections that can interrupt power along a circuit. If the neutral loses its continuity back to the main panel, the parts of the circuit that depend on that connection will no longer work.
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X-Bracing	Bracing system with members arranged diagonally in both directions to form an "X".
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Yard (of concrete)	One cubic yard of concrete is 3' x 3' x 3' in volume, or 27 cubic feet. One cubic yard of concrete will pour 80 square feet of 3.5' sidewalk or basement/garage floor.
Yield	The volume of freshly mixed concrete produced from a known quantity of ingredients. The total weight of ingredients divided by the unit weight of the freshly mixed concrete. The number of product units, such as block, produced per bag of cement or per batch of concrete.
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"Z" Section	A structural section in the shape of a "Z" cold formed from a steel sheet.
Zone	In HVAC an area within the interior space of a building, such as an individual room(s), to be cooled, heated, or ventilated. A zone has its own thermostat to control the flow of conditioned air into the space.