The 'ABCs' of construction terminology

Paul Bianchina

As with so many professions, the construction trades are filled with an alphabet soup of abbreviations. If you'd like to sound like a real pro next time you head for the lumberyard ? or at least feel less confused ? here's a roundup of some of the more common abbreviations that you're likely to run into.

ABS: acrylonitrile-butadiene-styrene, the chemical makeup of a black, plastic-composite plumbing pipe used extensively for drain, waste, and vent systems.

AC: alternating current, the most common method of delivering electricity in North America.

AWG: American Wire Gauge, the U.S. standard for the size of various types of wire, including electrical wire.

bd. ft. (also bf): board foot, a standard hardwood and softwood unit of measure equal to 1 inch thick, 12 inches wide, and 12 inches long.

Btu: British thermal unit, a standard unit for the measurement of heat, approximately equal to the heat given off by one kitchen match.

CAD: computer-assisted drafting. Also computer-assisted design.

CFM: cubic feet per minute, a measurement of how fast air moves.

cip: cast iron pipe.

cmu: concrete masonry unit, such as a concrete block.

d: penny, a common designation for the size of nails.

db: decibel, a standardized unit of measure for sound or noise.

DC: direct current, as from a battery.

DF-L: Douglas fir ? larch, a common species of softwood extensively used from framing lumber.

dia. (also diam.): diameter.

DWV: drain, waste and vent, the system of plumbing pipes used in the removal of liquid and solid waste from a building.

FAS: firsts and seconds, a common grade of hardwood lumber.

FIP: female iron pipe.

galv.: galvanized, meaning that a zinc coating has been applied to metals such as nails, fencing, and sheet metal for protection against the elements.

ga: gauge, typically meaning the diameter of a wire or the thickness of a piece of sheet metal.

GFI (also GFCI): ground fault interrupter, or ground fault circuit interrupter, an electrical device that senses a fault in the electrical system and shuts down power to that device.

HC: hollow core, a type of door that does not have a solid inner core.

hp: horsepower, a rating of the power output of an electric motor.

HVAC: heating, ventilating and air conditioning.

id: inside diameter, typically referring to a pipe or duct.

KD: knocked down, which refers to furniture or other items that are sold in pieces that are ready to assemble.

kw, kwh: kilowatt, a unit of electrical measure equal to 1,000 watts; and kilowatt-hour, equal to 1,000 watts of electricity used for one hour, the common measurement for how electricity is sold.

MBF: thousand board feet, a unit of measure for the pricing of many wood building materials.

MDF: Medium Density Fiberboard, a building material made from wood fiber and resin formed under heat and pressure in sheets, boards, and trim.

MIP: male iron pipe.

NC, NF: National Fine and National Coarse, two common designations of thread size for nuts, bolts, and other threaded objects.

NPT: National Pipe Taper, a standard type of threaded plumbing pipe and fittings.

OC: on-center, designating the measurement between the centers of two framing members.

od: outside diameter, typically referring to a pipe or duct.

OSB: Oriented Strand Board, a building material made from thin strands of wood and resin, formed under heat and pressure into sheets and boards.

PET: precision end trimmed, referring to lumber that has been trimmed to a specific length

PT: pressure-treated, a chemical treatment applied to lumber as a preservative.

PVA: polyvinyl resin adhesive, commonly used as a drywall sealer.

PVC: polyvinyl chloride, a widely used plastic composite material.

RO: rough opening, a framed opening that is specifically sized to receive a finished item such as a door, window, or skylight.

S4S: surfaced four sides, referring to lumber.

SC: solid core, a type of door with a solid inner core.

SF, SY: square foot and square yard.

T&G: tongue and groove, a method of milling interlocking lumber