Common Terms A-B
Here are some common terms relevant to home ownership.
A/C: An abbreviation for air conditioner or air conditioning.
A/C Circuit: Alternating Current. The flow of current through a conductor first in one direction, then in reverse. It is used exclusively in residential and commercial wiring because it provides greater flexibility in voltage selection and simplicity of equipment design.
A/C Condenser: The outside fan unit of the air conditioning system. It removes the heat from the Freon gas and turns the gas back into a liquid and pumps the liquid back to the coil in the furnace.
A/C Disconnect: The main electrical ON-OFF switch near the A/C condenser.
ABS: (Acrylonitrile butadiene styrene) Rigid black plastic pipe used only for drain lines.
Absolute Humidity: Amount of moisture in the air, indicated in grains per cubic foot
Accelerator: Any material added to stucco, plaster or mortar which speeds up the natural set.
Access Panel: An opening in the wall or ceiling near the fixture that allows access for servicing the plumbing/electrical system.
Accessible: Can be approached or entered by the inspector safely, without difficulty, fear or danger.
Acre: 43,560 square feet.
Acrylic: A glassy thermoplastic material that is vacuum-formed to cast and mold shapes that form the surface of fiberglass bathtubs, whirlpools, shower bases, and shower stalls.
Activate: To turn on, supply power, or enable systems, equipment, or devices to become active by normal operating controls. Examples include turning on the gas or water supply valves to the fixtures and appliances and activating electrical breakers or fuses.
Actual Dimension (Lumber): The exact measurement of lumber after it has been cut, dried and milled.
Adaptor: A fitting that unites different types of pipe together, e.g. ABS to cast iron pipe.
Adhesion: The property of a coating or sealant to bond to the surface to which it is applied.
Adhesive Failure: Loss of bond of a coating or sealant from the surface to which it is applied.
Adversely Affect: Constitute, or potentially constitute, a negative or destructive impact.
Aerator: An apparatus that mixes air into flowing water. It is screwed onto the end of a faucet spout to help reduce splashing.
Aggregate: Crushed stone, slag or water-worn gravel that comes in a wide range of sizes which is used to surface built-up roofs.
Air Chamber: A vertical, air-filled pipe that prevents water hammer by absorbing pressure when water is shut off at a faucet or valve.
Air Duct: Ducts, usually made of sheet metal, that carry cooled or heated air to all rooms.
Air Filters: Adhesive filters made of metal or various fibers that are coated with an adhesive liquid to which particles of lint and dust adhere. These filters will remove as much as 90% of the dirt if they do not become clogged. The more common filters are of the throwaway or disposable type.
Air Infiltration: The amount of air leaking in and out of a building through cracks in walls, windows and doors.
Air Space: The area between insulation facing and interior of exterior wall coverings. Normally a 1" air gap.
Air-Dried Lumber: Lumber that has been piled in yards or sheds for any length of time. For the United States as a whole, the minimum moisture content of thoroughly air dried lumber is 12 to 15 percent and the average is somewhat higher. In the South, air dried lumber may be no lower than 19 percent.
Airway: A space between roof insulation and roof boards provided for movement of air.
Alarm System: Warning devices, installed or free-standing, including but not limited to: carbon monoxide detectors, flue gas and other spillage detectors, security equipment, ejector pumps and smoke alarms.
Algae: Microorganisms that may grow to colonies in damp environments, including certain rooftops. They can discolor shingles. Often described as "fungus."
Alligatoring: A condition of paint or aged asphalt brought about by the loss of volatile oils and the oxidation caused by solar radiation. Causes a coarse checking pattern characterized by a slipping of the new paint coating over the old coating to the extent that the old coating can be seen through the fissures. "Alligatoring" produces a pattern of cracks resembling an alligator hide and is ultimately the result of the limited tolerance of paint or asphalt to thermal expansion or contraction.
Allowable Span: The distance between two supporting points for load bearing lumber such as joists, rafters or a girder.
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. Best kept to a minimum number and used for items whose choice will not impact earlier stages of the construction. For example, selection of tile because flooring may require an alternative framing or underlayment material. (Also, money that your parents give you as a child.)
Aluminum Wire: A conductor made of aluminum for carrying electricity. Aluminum is generally limited to the larger wire sizes. Due to its lower conductivity, aluminum wire smaller than No. 12 is not made. Aluminum is lighter and less expensive than copper, but does not conduct as well. It also breaks easily.
Amortization: A payment plan by which a loan is reduced through monthly payments of principal and interest.
Ampacity: Refers to the how much current a wire can safely carry. For example, a 12 gauge electrical copper wire can safely carry up to 20 amps.
Amperage: The rate of flow of electricity through wire - measured in terms of amperes.
Amps (AMPERES): The rate at which electricity flows through a conductor.
Anchor Bolts: In residential construction, bolts used to secure a wooden sill plate to a concrete or masonry floor or wall. In commercial construction, bolts which fasten columns, girders or other members to concrete or masonry such as bolts used to anchor sills to masonry foundation.
Angle Iron: A piece of iron that forms a right angle and is used to span openings and support masonry at the openings. In brick veneer, they are used to secure the veneer to the foundation. Also known as shelf angle.
Angle Stop: A shutoff valve in which the inlet connects to the water supply pipe in the wall and the outlet angles 90 degrees upward toward the faucet or toilet.
Annealing: In the manufacturing of float glass, the process of controlled cooling done in a Lahr to prevent residual stresses in the glass. Re-annealing is the process of removing objectionable stresses in glass by re-heating to a suitable temperature followed by controlled cooling.
Annual Percentage Rate (APR): Annual cost of credit over the life of a loan, including interest, service charges, points, loan fees, mortgage insurance, and other items.
Anti-Scald: A valve that restricts water flow to help prevent burn injuries. See Pressure Balancing Valve and Thermostatic Valve. In some areas, plumbing codes require anti-scald valves. Speak to a professional in your area for more information and help with code requirements.
Anti-Siphon: A device that prevents waste water from being drawn back into supply lines and possibly contaminating the water supply.
Anti-Walk Blocks: Elastomeric blocks that limit lateral glass movement in the glazing channel which may result from thermal, seismic, wind load effects, building movement, and other forces that may apply.
Antiquated: No longer in use, useful or functioning, as in most home inspection associations. Obsolete.
APA Plywood: (APA=American Plywood Association) Plywood that has been rated by the American Plywood Association. For example, number one APA rated exterior plywood contains no voids between laminate layers.
Aperature: The opening in pipes.
Appliance: A household device operated by use of electricity or gas. Not included in this definition are components covered under central heating, central cooling or plumbing.
Appraisal: An expert valuation of property.
Approach: The area between the sidewalk and the street that leads to a driveway or the transition from the street as you approach a driveway.
Apron: A trim board that is installed beneath a window sill.
Arbitration Service: A service to resolve complaints, as in NACHI's Arbitration Service.
Architect: A tradesman who designs and produces plans for buildings, often overseeing the building process.
Architects Rule (Ruler): Three sided ruler with different scales on each side. Also referred to as a "scale."
Architectural Service: Any practice involving the art and science of building design for construction of any structure or grouping of structures and the use of space within and surrounding the structures or the design, design development, preparation of construction contract documents, and administration of the construction contract
Area Wells: Corrugated metal or concrete barrier walls installed around a basement window to hold back the earth.
Areaway: An open subsurface space adjacent to a building used to admit light/air or as a means of access to a basement.
Asbestos: A common form of magnesium silicate which was used in various construction products due to its stability and resistance to fire. Asbestos exposure (caused by inhaling loose asbestos fibers) is associated with various forms of lung disease. The name given to certain inorganic minerals when they occur in fibrous form. Though fire-resistant, its extremely fine fibers are easily inhaled, and exposure to them over a period of years has been linked to cancers of the lung or lung-cavity lining and to asbestosis a severe lung impairment. A naturally occurring mineral fiber sometimes found in older homes. It is hazardous to your health when a possibility exists of exposure to inhalable fibers. Homeowners should be alert for friable (readily crumbled, brittle) asbestos and always seek professional advice in dealing with it.
Asphalt: A dark brown to black highly viscous hydrocarbon produced from the residue left after the distillation of petroleum. Asphalt is used on roofs and highways as a waterproofing agent.
Asphalt Plastic Cement: An asphalt-based cement used to bond roofing materials.
Assessment: A tax levied on a property, or a value placed on the worth of a property.
Associate Member: An indentured servant. Beginning level of inspection association membership. Slave. See Candidate.
Astragal: A molding which is attached to one of a pair of swinging doors against which the other door strikes.
Attic Access: An opening that is placed in the dry-walled ceiling of a home providing access to the attic.
Attic Ventilators: In houses, screened openings provided to ventilate an attic space. They are located in the soffit area as inlet ventilators and in the gable end or along the ridge as outlet ventilators. They can also consist of power-driven fans used as an exhaust system.
Auger: In carpentry, a wood-boring tool used by a carpenter to bore holes.
Awning Window: A window with hinges at the top allowing it to open out and up.
Back Nailing: The practice of nailing roofing felts to the deck under the overlap, in addition to hot mopping, to prevent slippage of felts.
Backer Rod: In glazing, a polyethylene or polyurethane foam material installed under compression and used to control sealant joint depth, provide a surface for sealant tooling, serve as a bond breaker to prevent three-sided adhesion, and provide an hour-glass contour of the finished bead.
Backfill: The slope of the ground adjacent to the house. In any previously excavated area, i.e., the replacement of excavated earth into a trench around and against a basement foundation. In carpentry, the process of fastening together two pieces of board by gluing blocks of wood in the interior angle.
Backflow: Movement of water (or other liquid) in any direction other than that intended.
Backflow Preventer: A device or means to prevent backflow into the potable water supply.
Backhand: A simple molding sometimes used around the outer edge of plain rectangular casing as a decorative feature.
Backhoe: Self-powered excavation equipment that digs by pulling a boom mounted bucket towards itself. It is used to dig basements and/or footings and to install drainage or sewer systems.
Backout: Work the framing contractor does after the mechanical subcontractors (Heating-Plumbing-Electrical) finish their phase of work at the rough (before insulation) stage to get the home ready for a municipal frame inspection. Generally, the framing contractor repairs anything disturbed by others and completes all framing necessary to pass a rough Frame Inspection.
Backsplash: A raised integral portion of a wall mount sink or lavatory located at the rear to protect the wall.
Balancing Damper: Baffle or plate used to control the volume of flowing air in a confined area.
Balloon Framing: In carpentry, the lightest and most economical form of construction in which the studding and corner plates are set up in continuous lengths from the first floor line or sill to the roof plate to which all floor joists are fastened.
Balusters: Usually small vertical members in a railing used between a top rail and the stair treads or a bottom rail.
Balustrade: A railing made up of balusters, top rail, and sometimes bottom rail, used on the edge of stairs, teal conies, and porches.
Barge: Horizontal beam rafter that supports shorter rafters.
Barge Board: A decorative board covering the projecting rafter (fly rafter) of the gable end. At the cornice, this member is a facie board.
Barometer: Instrument for measuring atmospheric pressure.
Barrel Roof: A roof design which in a cross section is arched.
Base Flashing: The upturned edge of a watertight membrane formed at a roof termination point by the extension of the felts vertically over the cant strip and up the wall for a varying distance where they are secured with mechanical fasteners.
Base Molding: Molding used to trim the upper edge of interior baseboard.
Base Ply: An asphalt-saturated and/or coated felt installed as the first ply with 4 inch laps in a built-up roof system under the following felts which can be installed in a shingle-like fashion.
Base Shoe: Molding used next to the floor on interior base board. Sometimes called a carpet strip.
Baseboard: Usually wood or vinyl installed around the perimeter of a room to cover the space where the wall and floor meet. A board placed against the wall around a room next to the floor to properly finish between the floor and the plaster.
Baseboard Heat: A heating system with the heating unit located along the perimeter of the wall where the baseboard would normally be located. It can be either an electric or hot water system.
Basement Window Inserts: The window frame and glass unit that is installed in the window buck.
Basket Strainer: Basket shaped strainer with holes allowing water to drain while catching food or other solids. Can also be closed to fill the sink with water.
Batt Insulation: Strips of insulation, usually fiberglass, that fit between studs or other framing.
Batten: Narrow strips of wood used to cover joints or as decorative vertical members over plywood or wide boards.
Batten Plate: A formed piece of metal designed to cover the joint between two lengths of metal edge.
Batter Board: One of a pair of horizontal boards nailed to posts set at the corners of an excavation, used to indicate the desired level, also used as a fastening for stretched strings to indicate outlines of foundation walls.
Batter Boards: Temporary structures that hold strings used to locate and square the corners of a building.
Bay Window: Any window space projecting outward from the walls of a building, either square or polygonal in plan.
Bead: In glazing, an applied sealant in a joint irrespective of the method of application, such as caulking bead, glazing bead, etc. Also a molding or stop used to hold glass or panels in position.
Beam: A supporting member either of wood or steel. Structural support member (steel, concrete, lumber) transversely supporting a load that transfers weight from one location to another.
Bearing Header: (a) A beam placed perpendicular to joists and to which joists are nailed in framing for a chimney, stairway, or other opening. (b) A wood lintel. (c) The horizontal structural member over an opening (for example over a door or window).
Bearing Partition: A partition that supports any vertical load in addition to its own weight.
Bearing Point: A point where a bearing or structural weight is concentrated and transferred to the foundation.
Bearing Wall: A wall that supports any vertical load in addition to its own weight.
Bed Molding: A molding in an angle, as between the over hanging cornice or eaves of a building and the side walls.
Bed or Bedding: In glazing, the bead compound or sealant applied between a light of glass or panel and the stationary stop or sight bar of the sash or frame. It is usually the first bead of compound or sealant to be applied when setting glass or panels.
Bedrock: A subsurface layer of earth that is suitable to support a structure.
Bell Reducer: In plumbing, a fitting shaped like a bell which has one opening of a smaller diameter used to reduce the size of the pipe in the line, and the opposite opening of larger diameter.
Below Grade: The portion of a building that is below ground level.
Bent Glass: Flat glass that has been shaped while hot into curved shapes.
Bevel: The angle of the front edge of a door usually from 1/8" to 2."
Bevel Siding (or Lap Siding): Wedge-shaped boards used as horizontal siding in a lapped pattern. This siding varies in butt thickness from ½ to ¾ inch and in widths up to 12 inches. Normally used over some type of sheathing.
Bid: A formal offer by a contractor, in accordance with specifications for a project, to do all or a phase of the work at a certain price in accordance with the terms and conditions stated in the offer.
Bid Bond: A bond issued by a surety on behalf of a contractor that provides assurance to the recipient of the contractor's bid that, if the bid is accepted, the contractor will execute a contract and provide a performance bond. Under the bond, the surety is obligated to pay the recipient of the bid the difference between the contractor's bid and the bid of the next lowest responsible bidder if the bid is accepted and the contractor fails to execute a contract or to provide a performance bond.
Bid Documents: Drawings, details, and specifications for a particular project.
Bid Security: Funds or a bid bond submitted with a bid as a guarantee to the recipient of the bid that the contractor, if awarded the contract, will execute the contract in accordance with the bidding requirements of the contract documents.
Bid Shopping: A practice by which contractors, both before and after their bids are submitted, attempt to obtain prices from potential subcontractors and material suppliers that are lower than the contractors' original estimates on which their bids are based, or after a contract is awarded, seek to induce subcontractors to reduce the subcontract price included in the bid.
Bidding Requirements: The procedures and conditions for the submission of bids. The requirements are included on documents, such as the notice to bidders, advertisements for bids, instructions to bidders, invitations to bid, and sample bid forms.
Bifold Door: Doors that are hinged in the middle to allow them to open in a smaller area than standard swing doors. Often used for closet doors.
Binder: A receipt for a deposit to secure the right to purchase a home at an agreed terms by a buyer and seller.
Bipass Doors: Doors that slide by each other. Commonly used as closet doors.
Bird's-Mouth Cut: A cutout in a rafter where it crosses the top plate of the wall providing a bearing surface for nailing. Also called a heel cut.
Bite: The dimension by which the framing system overlaps the edge of the glazing infill.
Bitumen: Any of various mixtures of hydrocarbons occurring naturally or obtained through the distillation of coal or petroleum. (See Coat Tar Pitch and Asphalt).
Blankets: Fiber-glass or rock-wool insulation that comes in long rolls 15 or 23 inches wide.
Bleeding: The migration of a liquid to the surface of a component or into/onto an adjacent material.
Blind Nailing: Nailing in such a way that the nail heads are not visible on the face of the work—usually at the tongue of matched boards.
Blind Stop: A rectangular molding, usually ¾ by 1-3/8 inches or more in width, used in the assembly of a window frame. Serves as a stop for storm and screen or combination windows and to resist air infiltration.
Blister: An enclosed raised spot evident on the surface of a building. They are mainly caused by the expansion of trapped air, water vapor, moisture or other gases.
Block Out: To install 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, or to depress the concrete at a garage door location.
Blocked (Door Blocking): Wood shims used between the door frame and the vertical structural wall framing members.
Blocked (Rafters): Short 2x4s used to keep rafters from twisting, and installed at the ends and at mid-span.
Blocking: In carpentry, the process of fastening together two pieces of board by gluing blocks of wood in the interior angle.
Blow Insulation: Fiber insulation in loose form used to insulate attics and existing walls where framing members are not exposed.
Blue Prints: Architectural plans for a building or construction project, which likely include floor plans, footing and foundation plans, elevations, plot plans, and various schedules and or details.
Blue Stain: A bluish or grayish discoloration of the sapwood caused the growth of certain mold like fungi on the surface and in the interior of a piece, made possible by the same conditions that favor the growth of other fungi.
Blue Stake: Also Utility Notification. When a utility company (telephone, gas, electric, cable TV, sewer and water, etc) comes to the job site and locates and spray paints the ground and/or installs small flags to show where their service is located underground.
Board and Batten: A method of siding in which the joints between vertically placed boards or plywood are covered by narrow strips of wood.
Board Foot: The volume of a piece of wood measuring 12 inches square and in inch thick. A piece of lumber 1/2" thick and 6 inches wide and 24 inches long is equal to one board foot.
Boards: Yard lumber less than 2 inches thick and 2 or more inches wide.
Bodied Linseed Oil: Linseed oil that has been thickened in viscosity by suitable processing with heat or chemicals. Bodied oils are obtainable in a great range in viscosity from a little greater than that of raw oil to just short of a jellied condition.
Boiled Linseed Oil: Linseed oil in which enough lead, manganese or cobalt salts have been incorporated to make the oil harden more rapidly when spread in thin coatings.
Bolster: A short horizontal timber or steel beam on top of a column to support and decrease the span of beams or girders.
Bond Breaker: A substance or a tape applied between two adjoining materials to prevent adhesion between them.
Bond or Bonding: An amount of money (usually $5,000-$10,000) which must be on deposit with a governmental agency in order to secure a contractor's license. The bond may be used to pay for the unpaid bills or disputed work of the contractor. Not to be confused with a performance bond. They are an insurance policy which guarantees proper completion of a project. Such bonds are rarely used in residential construction.
Bond Plaster: In addition to gypsum, bond plaster contains 2-5% lime by weight and chemical additives which improve the bond with dense non-porous surfaces such as concrete. It is used as a base coat.
Bonding Strip (Electrical): A thin strip of metal inside armored or BX cable. This strip is meant to back up the primary ground.
Boom: A truck used to hoist heavy material up and into place, to put trusses on a home or to set a heavy beam into place.
Boston Ridge: A method of applying asphalt or wood shingles at the ridge or at the hips of a roof as a finish.
Bottom Chord: The lower or bottom horizontal member of a truss.
Bottom Plate: The 2x4s or 6s that lay on the subfloor upon which the vertical studs are installed. Also called the sole plate.
Bow: A curve, bend, warping or other deviation from flatness in glass or wood.
Box Cornice: A cornice completely closed with trim work.
Brace: An inclined piece of framing lumber applied to wall or floor to stifled the structure. Often used on walls as temporary bracing until framing has been completed.
Bracing: Ties and rods used for supporting and strengthening various parts of a building used for lateral stability for columns and beams.
Brake Metal: Sheet metal that has been bent to the desired configuration.
Branch Circuit (Electrical): Wiring that runs from a service panel or sub-panel to outlets. Branch circuits are protected by fuses or breakers at the panel.
Breaker Box: A metal box that contains circuit breakers or fuses that control the electrical current in a home.
Breaker Panel: The electrical box that distributes electric power entering the home to each branch circuit (each plug and switch) and composed of circuit breakers.
Breeze Way: A roofed, open-sided passageway connecting two structures, such as a house and a garage.
Brick Ledge: Part of the foundation wall where brick (veneer) will rest.
Brick Lintel: The metal angle iron that brick rests on, especially above a window, door, or other opening.
Brick Mold: Trim used around an exterior door jamb onto which siding butts.
Brick Tie: A small, corrugated metal strip (1"x6"- 8" long) nailed to wall sheeting or studs. They are inserted into the grout mortar joint of the veneer brick, and hold the veneer wall to the sheeted wall behind it.
Brick Veneer: A facing of brick laid against and fastened to the sheathing of a frame wall or tile wall construction.
Bridging: Small wood or metal members that are inserted in a diagonal position between the floor joists at midspan to act as both tension and compression members for the purpose of bracing the joists a spreading the action of loads.
Broker: One that acts as an agent for others, as in negotiating contracts, purchases, or sales in return for a fee or commission.
Browncoat: The coat of plaster directly beneath the finish coat. In three-coat work, the brown is the second coat.
BTU: A measure of the capacity of a heating or cooling system. Abbreviation of British Thermal Unit. The amount of heat energy required to raise the temperature of one pound of water through a change of one degree Fahrenheit.
Bubbling: In glazing, open or closed pockets in a sealant caused by release, production or expansion of gasses.
Buck: Often used in reference to rough frame opening members. Door bucks used in reference to metal door frame.
Buckling: The bending of a building material as a result of wear and tear or contact with a substance such as water.
Builder's Risk Insurance: Insurance coverage on a construction project during construction, including extended coverage that may be added for the contract for the customer's protections.
Building Brick: Brick for building purposes not especially treated for texture or color, formerly called "common brick." It is stronger than face brick.
Building Code: Minimum local or state regulations established to protect health and safety. They apply to building design, construction, rehabilitation, repair, materials, occupancy and use. Community ordinances governing the manner in which a home may be constructed or modified.
Building Paper: A general term for papers, felts and similar sheet materials used in buildings without reference to their properties or uses. Generally comes in long rolls.
Building Permit: Written authorization from the city, county or other governing regulatory body giving permission to construct or renovate a building. A building permit is specific to the building project described in the application.
Built-Up Beam (or Girder): Beam (or girder) created by sistering or "scabbing" two or more pieces of lumber together.
Built-Up Roof: A roofing composed of three to five layers of asphalt felt laminated with coal tar, pitch, or asphalt. The top is finished with crushed slag or gravel. Generally used on flat or low-pitched roofs.
Bull Nose (Drywall): Rounded drywall corners.
Bullfloat: A tool used to finish and flatten a slab. After screeding, the first stage in the final finish of concrete, smoothes and levels hills and voids left after screeding. Sometimes substituted for darbying. A large flat or tool usually of wood, aluminum or magnesium with a handle.
Bundle: A package of shingles. There are 3, 4 or 5 bundles per square.
Bushing: A pipe fitting for joining pipes with different diameters. A bushing is threaded on the inside and outside.
Butt Glazing: The installation of glass products where the vertical glass edges are without structural supporting mullions.
Butt Joint: The junction where the ends of two timbers or other members meet in a square-cut joint.
Butterfly Roof: A roof assembly, which pitches sharply from either side toward the center.
Buttering: In glazing, application of sealant or compound to the flat surface of some member before placing the member in position, such as the buttering of a removable stop before fastening the stop in place.
Butyl: Type of non-curing and non-skinning sealant made from butylene. Usually used for internal applications.
Buy Down: A subsidy (usually paid by a builder or developer) to reduce monthly payments on a mortgage.
BX Cable: Armored electrical cable wrapped in galvanized steel outer covering. A factory assembly of insulated conductors inside a flexible metallic covering. It can be run anywhere except where exposed to excessive moisture. It should not be run below grade. It must always be grounded and uses its armor as an equipment ground. It is difficult to pull out old wires or insert new ones.