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Below are some commonly used construction terms. This list is short and in no way all inclusive, however it will help you understand the meaning of certain typical phrases or items within the construction and renovation industry.



Actual dimensions – The exact measurement of a piece of lumber. For instance, a 2X4 is actually 1½-inches thick and 3½-inches wide.

Adaptor – A fitting used to join pipes and other plumbing components.

Alcove - A recessed area in a room.

Ampere (Amp, A) – The unit of measurement of electrical current as it moves through a conductor.

Angle-nail – Driving nails into a substance at an angle.

Apex – The vertex; the highest point of something.

Apron - The trim below a window sill or table top.

Accessibility – The degree to which a certain building or site allows access to persons with disabilities.



Backer rod (foam backer rod) – A flexible, cylindrical-shaped material used for chinking wide joints; for enhanced sealant/caulking performance.

Balloon Framing – The method of early wood structure framing used primarily in the United States and Canada that utilized long continuous framing members that run from sill to eave line; popular at a time when long lumber was plentiful. Present day, this type framing has been replaced by platform framing.

Bat – Half of a brick; used to complete a wall course bond.

Batt – A section of fiberglass or rock-wool insulation

Batts (batten) – A narrow strip used to cover joints between boards or panels.

Balusters – Spindles that add support to a staircase handrail.

Beam – A horizontal support.

Bearing Wall – Exterior or interior walls that lends support to the roof or overhead floor joists.

Blanket – Fiberglass or rock-wool insulation that comes in a roll.

Blind-nailing – A method of driving nails into tongue-and-groove planks in a way that hides them from sight. Drive the nail into the tongue of the plank at an angle; make sure the head is recessed. Slide the grooved side of the succeeding board over the tongue, hiding the nail head.

Blocking – Bridging lengths of solid wood between floor joists for extra support and to eliminate squeaks. Staggering alternately on each side of the chalk line offsets the blocks; allowing you to nail each block firmly in place more easily, without having to angle-nail.

Bond – 1. The pattern in which bricks or other masonry unites are laid. 2. The cementing action of an adhesive, such as glue.

Box – To mix containers of the same kind and color of paint together to ensure the color will be exact throughout the painting project.

Breaker box – An insulated box that contains mounted circuit breakers or fuses that control the electrical current in a structure.

Bridging – Boards nailed between joists for rigidity and to keep the joists from warping.

British thermal unit (BTU) – The amount of heat required to raise 1 pound of water 1 degree Fahrenheit.

Building codes – Ordinances for safety purposes that govern the manner in which a structure is constructed or modified; codes can be national, providence or statewide, or local. Local codes supersede other codes.

Bulkhead enclosures - A partition, wall, or embankment that acts as a protective barrier.

Butt – Materials placed end-to-end or end-to-edge, without overlapping.

Butt hinge – The most common type of hinge; one leaf attached to the door’s edge, the other to its jamb.

Buttjoints – Formed by edges of wallboard that join together when constructing a wall, for instance; seams are taped, covered with compound, and then sanded with the end goal of a flat surface with invisible seams.



Cantilever – A beam or beams that projects beyond its support.

Carpenter’s square – a handheld tool larger than a try square; used as a guide for establishing 90-degree (right) angles; made of metal in the shape of a right triangle.

Casing - The enclosing frame around a door, window, or other opening.

Cats Paw – A tool similar to a small crowbar; used in small work spaces, or tight areas.

Caulk – A variety of compounds used to seal seams and joints.

Cement – A powder that serves as a binding element in concrete and mortar.

Cementboard – Sometimes called cement backer board or a glass mesh mortar unit; made specifically for use under ceramic tile.

Cfm (cubic feet per minute) – The amount of air a blower or fan is capable of moving.

Chalk line – An encased reel of string coated with colored chalk; used to mark straight lines.

Chalking – The tendency of some exterior paints to slowly erode over a period of time.

Circuit breaker – A safety switch designed to automatically shut off electrical current to avoid a circuit overload.

Compound miter –A saw with a box, used to cut wood at a tilted angle for accurate, smooth, clean bevel and miter cuts; especially useful for cutting trim and crown molding, and for cutting paneling for ceilings without 90-degree angles.

Compressor – The part of a cooling unit or heat pump that compresses refrigerant gas so it absorbs heat.

Concrete – A mixture of water, sand, gravel, and cement; one of the more basic building and paving materials.

Condensing unit – The outdoor section of a cooling system; it includes a compressor and condensing coil.

Conduit – Metal pipes encased over electrical wiring to protect it in exposed settings.

Construction grade plywood – Various types of a thicker, more durable grade of plywood manufactured for particular purposes, and to meet or exceed building code requirements for certain types of construction projects.

Coping – 1. A rounded or beveled cap located at the top of a wall so water will run off. 2. A curved cut that neatly joins one contoured molding with another.

Corner bead – Lightweight, perforated metal angle; used to reinforce outside corners in drywall construction.

Coupling – A fitting used to connect two lengths of pipes in a straight run.

Courses – Parallel layers of building materials; bricks, shingles, siding, etc.

Cornice - A horizontal molded projection that completes a building or wall; the molding between the wall and ceiling.

Counterbore – A pre-drilled pilot hole with a larger hole drilled in the center to allow screw heads to rest flush or just below the surface.

Cove - A concave surface that connects the ceiling and a wall; a type of molding used to join vertical surfaces to horizontal ones.

Cripple – A short stud above or below a window or door opening; short studs placed between the header and a top plate, or sill and bottom plate.

Crosscut – To cut wood across its natural grain.

Crown – 1. A slightly humped surface on paving that allows water to run off. 2. A contoured molding installed at the junctures of walls and ceilings.

Cupping – A type of warping that causes the edges of boards to curl up.



Dado – A groove cut into a piece of wood to secure a plank or board in place.

Damper – A valve inside a cut or flue; used to slow or stop the flow of air or smoke.

Deadbolt – A locking device with squared-off ends, activated with a key or thumb turn.

Digital multi-meter – A relatively inexpensive compact, easy to use instrument used for home electrical applications; easier to use than an analog Ohm meter, with wire probes and a digital display. Some models also have a select mode function.

Dormer window - A window vertically set in a structure, projecting through a sloping roof.

Double cylinder – A lock that is operated with a key from the inside as well as the outside.

Drywall – Sheet masonry wall panels without mortar.

Drywall compound (also known as mud) – A highly extended paste used to make a continuous seam between pieces of wallboard (drywall, sheetrock) that should be sanded smooth after use; also used to repair cracks, holes, and other defects.

Drywall knife – A small hand tool with a blade; for application of drywall compound; available in various widths and handle lengths.

Drain-waste-vent (DWV) – The network of pipes used to carry water and sewer gases out of the home.

Ducts – Round or rectangular metal pipes that transport warm or cold air from either a furnace or air conditioner to rooms in a house.



Easement – A legal right for restricted use of someone’s property.

Eaves – The lower edge of a roof that projects away from the wall.

Efflorescence – A whitish powder that sometimes oozes from the mortar joints in masonry work.

Egress - An opening for going out; an exit point.

Elastomeric caulk – A durable, paintable latex sealant; more expensive than other type caulks, but better for specific applications.

Elbow (L) – A plumbing or electrical fitting that allows you to change direction in lengths of pipe or conduit.

Elevation drawing – 1. A drawing of the exterior or interior of a building as seen from a horizontal position - without dimensional perspective. 2. The side view of a room detailing one wall per drawing.

Evaporator coil – A cooling system part that absorbs heat from air in a structure.

Expansion joint – Flexible material between two surfaces, allowing joints differing rates of expansion and contraction.

Exterior grade plywood (WBP; water and boil proof) – Plywood treated with durable veneers, bonded with waterproof adhesive. It is capable of withstanding prolonged exposure to even severe exterior conditions.



Fall – The slope of drain pipes; minimum fall is 1/4-inch per foot.

Fascia board – Horizontal trim attached to the outside ends of rafters, or to the top of an exterior wall.

Female – Any part with internal threads that allows another part to be inserted and attached.

Fire blocking – Short horizontal members nailed between studs.

Fish tape – A flexible, flat metal wire used to move other wires through conduits or other hard to access locations in a structure; also referred to as steel fish tape or fish wire.

Fitting – Any pipe connector other than a valve.

Fixture – Any device providing a flow of water, or sanitary disposal of wastes; this includes bathtubs, showers, toilets, and sinks.

Flangs – The part of a window that surrounds the frame; for mounting in place and installation.

Flashing – Metal or composition strips used to seal junctions between roofing and other surfaces.

Floating – The stage just before the final stage in concrete work, where you introduce water and smooth off the surface.

Floor plan – A scale drawing that depicts the rooms of a house, including the orientation of doors, walls, windows, and permanent fixtures.

Flue – A pipe or other channel that carries smoke and combustion gases to the outside air.

Footing – The base on which a masonry wall rests.

Frame fins – The members of a window frame that engage with the exterior surface of a building once inserted into position. Used to attach the frame to the exterior of a structure; secured with nails or screws

Framing – The structural skeleton or framework of a building.

Framing square – A flat tool made of metal, shaped like an “L,” used to form accurate right angles. Most commonly used for marking perpendicular lines along the length of lumber during construction projects.

Furred - A wall, ceiling, or floor prepared with the use of strips of wood or metal to provide a level substratum for plaster, flooring, or another surface; or to create an air space.

Furring Strips – Long thing strips of wood used to make backing surfaces support finished surfaces in a room. Furring can refer to the strips themselves, or “to fur;” the process of installing the strips. Note: some building codes in communities that support fire-proof supporting elements require the use of metal furring strips. So be sure and check what your local building code requirements are before installing any.

Fuse – A safety device that burns out if a circuit shorts or overloads.



Gable – The triangular area located beneath the sloping parts of a roof, and the line that runs between the roof’s eaves.

Galvanized – An outer covering of zinc that protects against rusting.

Gate valve – A valve that completely stops the flow of water.

Girder – The main supporting beam of the house.

Glazing – The process of installing glass; securing it with glazier’s points and glazing compound.

Globe valve – A valve that adjusts the flow of water.

Grade – 1. Ground level. 2. The elevation at any given point.

Graphite –A soft, black carbon powder for lubricating working metal parts.

Gross Floor Area – A measurable floor area that is usable.

Ground – The shortest route to earth, in regards to electricity.

Ground-fault circuit interrupter (GFCI) – A safety device capable of detecting electrical leakage and interrupts the current.

Grout – Thin mortar used to fill the joints between tiles or other masonry.

Gypsum Wallboard – A type of wallboard made from layers of gypsum (plaster of Paris) and paper; commonly used in walls and partitions as a substitute for plaster.



Habitable Rooms – Any room used as, or with the intended use of sleeping, cooking, living, or eating; enclosed spaces such as toilets, landings, halls, lobbies, utility rooms, etc. are excluded.

Hardboard – A substance manufactured by pressing wood fibers into sheet goods to be used as building material.

Header – Heavy framing above the top of a window, door, or other opening that lends support; usually two boards or a masonry product sandwiched together and laid on edge.

Hip – The outside angle of a roof; formed by the intersection of two sloped sides of the roof.

Hot wire – The wire that carries electricity away, to a receptacle or other device.

HVAC - Heating, ventilation and air conditioning.


I - J

IAQ (Indoor Air Quality) – Interior air quality, increasingly recognized as important to health; this includes gaseous composition, temperature, relative humidity; and airborne contaminant levels, such as pollen and dust.

Jack studs (trimmers) – Studs at both sides of an opening, used to support the header.

Jamb – The top and sides of an opening.

Keyhole saw – A handheld saw, also called a jab saw or drywall saw; similar to a compass saw. Typically, it has a long narrow blade with a sharpened point that can be pushed through soft materials without pre-drilling a hole for the blade to fit through. Used for cutting short radius curves in such surfaces as drywall and plywood

Jigsaw – A power saw used to cut curved, irregular, and intricate patterns; it has a thin blade that moves up and down.

Joint compound – A synthetic-based paste used in combination with paper or fiberglass tape to conceal joints between drywall panels.

Joint Tape – A special type paper tape or paper-faced cotton; used over joints between wallboard applied as a surface. Helping to conceal the joints and provide a smooth surface for finishing (painting, texturing, etc.).

Joists – Horizontal floor and ceiling framing supports.


K - L

King studs – The studs located on both ends of a header that lend support, and run from the wall’s sole plate to its top plate.

Lag screw – A large wood screw with a hexagonal head; secured in place using a wrench instead of a screwdriver.

Laminate – 1. The process of applying a veneer. 2. A Thin layer of material (i.e. wood, plastic) glued to the exterior of a surface.

Latch – A beveled metal tongued locking device with a spring-loaded knob or lever.

Lattice - Wood or other material formed into an open cross-hatch design.

Ledger – The horizontal support for an end or edge of an assembly.

Level – A tool used to determine true horizontal, or level.

Lintel – The load-bearing beam over an opening.

Load-bearing wall – Also called a bearing wall, a load-bearing wall supports the house structure, transferring the structure’s weight to the foundation. This includes all exterior walls and any interior wall aligned above a support beam or girder; normally, any wall with a double horizontal top plate.

Louver - A framed opening fitted with fixed or movable horizontal slats for admitting air and light, while shedding rain.

Low-voltage wiring – Electrical wire for low-voltage systems requiring between 6 and 30 volts.



Main drain – The part of the drainage system between the home’s sewer drain and fixture drains.

Male – Any part with external threads that fits into and attaches to another part.

Masonry Chisel – A tool with a flat steel blade used for cutting or chipping away stone and masonry.

Mason’s line – A heavy string, usually brightly colored, that does not snag or stretch; used for marking the placement of building materials or indicate level of a wall.

Materials list – A list of materials required to complete a new construction or renovation project.

Measurable floor area - The floor area under ceilings 5 ft. and higher, or furred ceilings 7 1/2 ft. and higher.

Miter – A joint formed by beveling the edges or ends of two pieces of material, fitted together at an angle.

Molding - A strip of wood or other material used to decorate or finish a surface.

Mortar – The bonding agent between bricks or other masonry.

Mortise – The hole, slot, or other recess into which another element fits.

Mud – (See “drywall compound.”)



Nail set – A short metal rod with a narrow blunt point; used to set nail heads below the surface of wood.

National Electrical Code (NEC) – A set of rules for safe wiring practices.

Neutral wire – A wire that carries electricity from an outlet back to the ground; usually color-coded white.

National Uniform Plumbing Code (NUFC) – A complex manual of acceptable plumbing standards for safety purposes.

Newel post – A post at the top of a staircase or bottom of the landing, secured to the handrail.

Nipple – A short length of threaded pipe that connects to runs of water or gas supply pipe.

NM electrical cable – A type power cable with a nonmetallic jacket used by electricians that meets electrical code requirements for safe installation and wiring; sometimes also referred to as Romex™,

Nominal dimensions – Labels given to a standard piece of lumber before it is finished by planning; sometimes sanded down to its actual dimensions.



Ohm meter (also known as VOM) – A hand-held device used to test cables, AC power levels and batteries; it has a needle that moves left to right, a type rotary switch, and set of wire probes.

On center (OC) – The distance from the center of one regularly spaced framing member to the center of the next.



P-trap – A p-shaped section of drain pipe that prevents sewer odors and toxic gases from escaping into your home; a plumbing device located directly below the sink or drain that holds water, preventing sewer gas backup.

Packing nut – A nut with packing material that holds the stem of a valve in place.

Pennyweight – A system of measurement for the size of a nail.

Perlins – The horizontal members of a roof’s structure that attaches and supports roof panels; horizontal lengths of lumber that connect rafter trusses.

Pier – A masonry post.

Pilot hole – A small-diameter hole to guide a nail or screw.

Pilot light – A small, continuous flame that ignites gas or oil burners once turned on.

Platform framing – The most common method of light-frame construction framing used for houses, small apartment buildings, and occasionally for small commercial buildings throughout the United States and Canada. Platform framing uses studs that are attached to floor-level bottom plates. This type framing requires not only shorter pieces of lumber than balloon framing, but makes home structural renovation changes much easier.

Plenum – The large hot-air supply duct that leads from the furnace before branching into ducts.

Plumb – True vertical.

Plumb bob – A lead weight attached to a string; used in determining plumb.

Plumber’s putty – A product some plumbers use as a sealant when installing drain basins such as kitchen, laundry, and bathroom sinks; showers and bathtubs. Note: products such as silicone caulking have become the preference of an increasing number of plumber’s when installing drain basins; due to its superior bonding properties that decrease the risk of product breakdown and future leaks.

Point – Filling the cracks of masonry wall with mortar or cement to finish it off.

Post-and-beam – A basic building method where a few hefty posts and beams are used to support an entire structure.

Pressure-treated wood – Lumber treated with a preservative.

Primer – A base coat formulated to seal raw surfaces and hold succeeding finish coats.

Property value – The value of a piece of property based upon a recent appraisal and the amount a buyer will pay.

PVC – A type plastic pipe used for cold, not hot water.

PVC-U – An unplasticised version of PVC; made from polymere. It was once referred to as uPVC (for unplasticised PVC); the term was changed to PVC-U in 1990 in order to conform to the international naming conventions for polymers.


Q - R

Rafters – Framing members that run parallel and support the roof.

Rake – The inclined edge of a roof.

Reducer – A fitting with openings in various sizes used to connect a larger pipe to a smaller one.

Ridge board – The topmost beam located at the peak of a roof to which rafters are attached; the horizontal board that serves as the apex, the highest point, of the roof or ceiling.

Rip / Ripping – To trim or saw a board by following the grain.

Rise – The vertical distance from one point to another above it.

Riser – The upright piece between two stair steps.

Rough opening – The framed-in opening of a structure; the opening left in a frame wall to receive a window or door unit. Openings are larger than the size of the unit to allow space for insulation and to shim the unit square.

Roughing-in – The initial stage of a construction or renovation project, once all plumbing, carpentry, and electrical components that won’t be seen after the second finishing phase are assembled.

Run – 1. The horizontal distance of a ramp or stairway. 2. A line of pipes or cabinets.

R-value – The measure of the resistance to heat transfer of an insulating material.



Sash – The part of a window that can be opened.

Screed – The board used to level concrete once it has been poured into a form.

Set screw – Used to prevent loosening due to vibration; available as thumb screw, square head, Allen head (inset socket), and most commonly – headless; designed to be inserted flush with or below a surface.

Setback – 1. The distance a home must be built from property lines, governed by local zoning codes. 2. Temporary change in a thermostat’s setting.

Shake – A wood shingle that has been split, instead of cut.

Sheathing – The first covering on a roof or exterior wall.

Sheet goods – Plywood and similar materials manufactured as panels.

Shim – Thin material used as wedges to make level or plumb adjustments.

Shoe molding (base shoe) – Molding along the point where the baseboard meets the floor.

Sill –The lowest horizontal piece of a window, door, or wall framework.

Sill cock – The valve of an outdoor faucet.

Sill plate – A sole plate that rests on a foundation; the first component of framing a house, supporting the house structure.

Sisal - A natural, durable fiber frequently used in floor coverings.

Sleepers – Boards that lay over a masonry floor, used as nailers for plywood, strip, or wood flooring.

Snap ring – A small metal ring. When installing a sink, it holds the entire under the counter sink assembly tight and securely in place.

Soffit - The underside of a structural element; i.e. beam, arch, cornice, eaves, or staircase.

Soil pipe – A large pipe used to carry liquid and solid wastes to a sewer or septic tank.

Sole plate – The bottommost horizontal part of a stud partition; supported by a wood subfloor, concrete slab, or another closed surface.

Sound transmission class (STC) – A rating of airborne sound transmission; used for floor, ceiling, wall soundproof values. Typical sound proof values range from a modest 25 to 35 rating for lightweight, single family residential structures; room partitions for commercial structures may have increased STC ratings upwards of 50 to 60. Many homeowners elect to increase STC rating to soundproof certain rooms of the house; such as home theaters, home offices, bedrooms, guest quarters, family recreation rooms, etc.

Spackle / Spackling compound – A paste that can be sanded once dried; used to fill cracks and holes in walls.

Span – The distance between supports

Spline – A thin piece of wood used to strengthen the joint; fitted into the slots on the edges of two joined boards.

Square – Surfaces positioned at a 90-degree angle to each other.

Square notched trowel – A handheld tool with different notched depths; used to spread and “comb” adhesives and other similar products onto underlayment or other horizontal surfaces. Most frequently used for installing floor tile.

Stack – The main drain pipe that runs vertically through a house.

STC – (See “sound transmission class.”)

Steel fish tape – (See “fish tape.”)

Strike – The plate on a door frame that engages a latch or dead bolt.

Stile – The vertical section of a cabinet facing.

Stringer – A long piece of lumber used to support stairs.

Studs – Vertical framing members spaced at regular intervals within a wall.

Stud finder – An electronic or magnetic tool used to locate wall studs.

Subfloor – The first layer of a floor.

Substratum - An underlying layer. The foundation; material on which another material is attached.

Surform plane – A type plane with various blades for special purposes; one with precision sharpened, hard teeth set to produce consistent quality cuts.

Sweep – A flexible strip on the bottom edge of a door to prevent drafts.

Swing stapler (hammer tacker) – A small, hand-held heavy duty stapling device that requires one-hand operation; used with a swinging motion much like that of a hammer. Ideal for installing insulation, poly sheeting, tar paper, carpet, house wrap, etc.



T – T-shaped plumbing fitting.

T-square – 1. A tool with a 48-inch long tongue; typically made from aluminum, used to measure and cut wallboard. 2. A technical drawing instrument primarily used for drawing lines on a drafting table

Tailpiece – 1. The short drainpipe located between a fixture drain and a trap. 2. The inlet tubes on faucets that connect it to water supply lines.

Taping – The process of covering drywall joints with paper tape and joint compound.

Threshold (saddle) – The plate located at the bottom of some door openings; usually on the exterior.

Toenail – Nailing at an angle to attach two boards together; diagonally through the corner of one board into the other board.

Top plate – The uppermost horizontal element of a stud-frame wall.

Trap – A bend in a drainpipe that creates a water seal to prevent toxic gases from escaping through fixtures into the house.

Tread – The level part of a staircase.



Underlayment (sub-floor material) – A cement-like product that is used to level floors before laying down any surface material.

Union – A plumbing fitting used to join pipes end to end.

Universal Design - Physically challenged friendly; products and environments accessible and useable by all people regardless of age, size, or physical ability.

Utility knife – A knife with a long handle and a retractable razor blade.



Valley – Where two roof slopes intersect.

Vapor barrier – Waterproof material that blocks the transfer of moisture in a wall, floor, or ceiling.

Veneer - Thin sheets of wood applied to the surface of furniture.



Wainscoting - Decorative wood paneling that only covers the lower half of a wall.

Warping – Distortion in a material.

Wet wall – A wall framed to enclose the building’s main drain/vent stack, water lines, and DWV lines.


X - Y - Z

Y – A y-shaped plumbing fitting.

Zoning – Local ordinances that govern ways in which a piece of property can be used in a particular neighborhood.

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