Glossary of Construction Terminology



padding - A material installed under carpet to add foot comfort, isolate sound, and to prolong carpet life.

paint - A combination of pigments with suitable thinners or oils to provide decorative and protective coatings. Can be oil based or latex water based.

panel - In home construction - a thin flat piece of wood, or similar material, framed by stiles and rails as in a door, or fitted into grooves of thicker material with molded edges for decorative wall treatment.

paper, building - A general term for papers, felts, and similar sheet materials used in buildings without reference to their properties or uses.

paper, sheathing - A building material, generally paper or felt, used in wall or roof construction as a protection against the passage of air and sometimes moisture.

particle board - Plywood substitute made of course sawdust that is mixed with resin and pressed into sheets. Used for closet shelving, floor underlayment, stair treads, etc.

partition - A wall that subdivides spaces within any story of a building.

parapet wall - A low wall around the perimeter of a roof deck.

pavers - Materials, commonly masonry, laid down to made a firm, even surface.

pedestal - A metal box installed at various locations along utility easements that contain electrical, telephone, or cable television switches and connections.

perimeter drain - 3" or 4" perforated plastic pipe that goes around the perimeter (either inside or outside) of a foundation wall (before backfill)and collects and diverts ground water away from the foundation. Generally, it is "daylighted" into a sump pit inside the home and a sump pump is sometimes inserted into the pit to discharge any accumulation of water.

pier - A column of masonry, usually rectangular in horizontal cross section, used to support other structural members.

pigment - A powdered solid used in paint or enamel to give it color.

pilot hole - A small-diameter, pre-drilled hole that guides a nail or screw.

pitch - The incline slope of a roof or the ratio of the total rise to the total width of a house, i.e., an 6-ft rise and 24-ft width is a one-fourth pitch roof. Roof slope is expressed in the inches of rise, per foot of horizontal run.

plate - Sill plate, a horizontal member anchored to a masonry wall. Sole plate, bottom horizontal member of a frame wall. Top plate, top horizontal member of a frame wall supporting ceiling joists, rafters, or other members.

plenum - The main hot-air supply duct leading from a furnace.

plot plan - An overhead view plan that shows the location of the home on the lot. Includes all easements, property lines, set backs, and legal descriptions of the home. Provided by the surveyor.

plumb - Exactly vertical and perpendicular.

plumb bob - A lead weight attached to a string. It is the tool used in determining plumb.

plumbing rough - Work performed by the plumbing contractor after the Rough Heat is installed. This work includes installing all plastic ABS drain and waste lines, copper water lines, bath tubs, shower pans, and gas piping to furnaces and fireplaces.

plumbing stack - A plumbing vent pipe that penetrates the roof.

plumbing trim - Work performed by the plumbing contractor to get the home ready for a final plumbing inspection. Includes installing all toilets (water closets), hot water heaters, sinks, connecting all gas pipe to appliances, disposal, dishwasher, and all plumbing items.

plumbing waste line - Plastic pipe used to collect and drain sewage water.

ply - A term to denote the number of layers of roofing felt, veneer in plywood, or layers in built-up materials, in any finished piece of such material.

plywood - Wooden panels formed by gluing thin sheets of wood together, with the grain of adjacent layers arranged at right angles.

Portland cement - Cement made by heating clay and crushed limestone into a brick and then grinding to a pulverized state.

post - A vertical member of wood, steel, concrete or other material that transfers weight from the top of the post to whatever the post is resting on.

post & beam - A basic building method that uses just a few hefty posts and beams to support an entire structure. Contrasts with stud framing.

power vent - A vent that includes a fan to speed up air flow. Often used on roofs.

precast - Concrete building components which are formed and cured at a factory and then transported to a work site for erection.

preservative - Any substance that, for a reasonable length of time, will prevent the action of wood-destroying fungi, borers of various kinds, and similar destructive agents when the wood has been properly coated or impregnated with it.

pressure reducing valve - Valve installed in the water service line where it enters the building to reduce the pressure of water in the line to an acceptable pressure used in buildings.

pressure relief valve - Valve to relieve excess pressure in water storage tanks.

pressure treated wood - Lumber that has been saturated with a preservative.

primer - A material of relatively thin consistency applied to a surface for the purpose of creating a more secure boning surface and to form a barrier to prevent migration of components.

P trap - Curved, "U" section of drain pipe that holds a water seal to prevent sewer gasses from entering the home through a fixtures water drain.

punch list - A list of discrepancies that need to be corrected by the contractor.

purlins - A horizontal structural member spanning between beams or trusses to support a roof deck. In slope glazing, purlins are the horizontal framing members.

putty - A type of dough used in sealing glass in the sash, filling small holes and crevices in wood, and for similar purposes.

PVC or CPVC - Poly Vinyl Chloride - a type of white or light gray plastic pipe sometimes used for water supply supply lines and waste pipe.


quarry tile - A man-made or machine-made clay tile used to finish a floor or wall. Generally 6" x 6" x 1/4" thick.

quarter round - A small trim molding that has the cross section of a quarter circle.


rabbit - A rectangular longitudinal groove cut in the corner edge of a board or plank.

radiant heating - A method of heating, usually consisting of a forced hot water system with pipes placed in the floor, wall, or ceiling. Also electrically heated panels.

radiation - Energy transmitted from a heat source to the air around it. Radiators actually depend more on convection than radiation.

radon - A naturally occurring, heavier than air, radioactive gas common in many parts of the country. Radon gas exposure is associated with lung cancer. Mitigation measures may involve crawl space and basement venting and various forms of vapor barriers.

radon system - A ventilation system beneath the floor of a basement and/or structural wood floor and designed to fan exhaust radon gas to the outside of the home.

rafter - One of a series of structural members of a roof designed to support roof loads. The rafters of a flat roof are sometimes called roof joists.

rafter, hip - A rafter that forms the intersection of an external roof angle.

rafter, valley - A rafter that forms the intersection of an internal roof angle. The valley rafter is normally made of double 2"-thick members.

rail - The top and bottom frame members of a door or window (not the jamb).

rake - The angle of slope of a roof rafter, or the inclined portion of a cornice.

re-bar - Reinforcing bar used to increase the tensile strength of concrete.

receptacle - An electrical outlet. A typical household will have many 120V receptacles for plugging in lamps and appliances and 240V receptacles for the range, clothes dryer, air conditioners, etc.

redline, red lined prints - Blueprints that reflect changes and that are marked in red pencil.

reducer - A fitting with different size openings at either end and used to go from a larger to a smaller pipe.

reflective glass - Glass with a metallic coating to reduce solar heat gain.

reflective insulation - Sheet material with one or both faces covered with aluminum foil.

register - A grill placed over a heating duct or cold air return.

reglaze - To replace a broken window.

reinforced concrete - A combination of steel and concrete using the best properties of each. The steel consists of rebar or reinforcing bars varying from 3/8" to 2-1/4" in diameter and is placed before concrete is poured.

reinforced masonry - Masonry units, reinforcing steel, grout and/or mortar combined to act together to strengthen the masonry structure.

relative heat gain - The amount of heat gain through a glass product taking into consideration the effects of solar heat gain (shading coefficient) and conductive heat gain (U-value).

relief valve - A device designed to open if it detects excess temperature or pressure.

retaining wall - A structure that holds back a slope and prevents erosion.

retentions - Amounts withheld from progress billings until final and satisfactory project completion.

return - In heating and cooling systems, a vent that returns cold air to be warmed. In a hot air furnace system, it is located near an inside wall.

R-factor or value - A measure of a materials resistance to the passage of heat. New home walls are usually insulated with 4" of batt insulation with an R value of R-13 and a ceiling insulation of R-30.

rigid metal conduit - This conduit resembles plumbing pipe, protecting wires from damage.

rim joist - A joist that runs around the perimeter of the floor joists and home.

rise - In stairs, the vertical height of a step or flight of stairs.

riser - Each of the vertical boards closing the spaces between the treads of stairways.

riser pipe - The exterior vertical pipe that encases the electrical supply lines from the point of supply, down to the electrical service panel.

road base - A aggregate mixture of sand and stone.

Romex - A name brand of nonmetallic sheathed electrical cable that is used for indoor wiring, within walls, in attics and under neath the house.

roll roofing - Asphalt roofing products manufactured in roll form, 36" wide rolls with 108 sq ft of material. Weights are generally 45 to 60 lbs per roll.

roof jack - Sleeves that fit around any pipe that extends above the roof line, and are nailed to the roof sheeting.

roof sheathing - The boards or sheet material fastened to the roof rafters on which the shingle or other roof covering is laid.

roughing-in - The initial stage of a plumbing, electrical, heating, carpentry and/or other project, when all components that won't be seen after the second finishing phase are assembled.

rough opening - The horizontal and vertical measurement of a window or door opening before drywall or siding is installed.

rough sill - The framing member at the bottom of a rough opening for a window. It is attached to the cripple studs below the rough opening.

run - The horizontal distance between the eaves and the ridge of the roof, being half the span for a symmetrical gable roof.

r-value - see R Factor above.