P-trap: A P-shaped section of drainpipe that traps water, which prevents sewer odors from escaping through the drain and into the home.

 

pad out: To shim out or add strips of wood to a wall or ceiling so that the finished wall or ceiling will appear level. Also called pack out.

 

padding: Material installed under carpeting to add depth and plushness, minimize sound, and prolong the carpet's life.

 

paint: A combination of pigments with suitable thinners or oils to provide a decorative and protective coating.

 

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

 

panelboard: A component of the electricity-supply system that divides the electrical power feed into subsidiary circuits, with buss bars and automatic over-current devices, in a common enclosure accessible only from the front. Also called a distribution board.

 

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

 

parge coat: A thin coat of cementitious or polymeric mortar applied to concrete for refinement of the surface.

 

parking strip: The area in front of a building between the sidewalk and the street, usually landscaped with grass, that serves as a buffer between the road and pedestrians walking on the sidewalk.

 

parting stop: A small wood piece used in the side and head jambs of double-hung windows to separate the upper and lower sashes. Also called a parting strip.

 

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

 

patterned glass: A type of rolled glass having a pattern impressed on one or both sides and commonly used for light control, bath enclosures, and decorative glazing. Also called rolled glass, figured glass and obscure glass.

 

paver stones: Pre-cast concrete slabs used to create a traffic surface.

 

pedestal lavatory: A sink whose washbasin is supported by a single pedestal leg.

 

penny: As applied to nails, it originally indicated the price per hundred. The term now serves as a measure of nail length and is abbreviated by the letter D.

 

percolation test (perc test): A test that a soil engineer performs on soil to determine the feasibility of installing a leach field-type sewer system on a proposed building lot, evaluating whether the soil is capable of absorbing the liquid effluent from a septic system.

 

perimeter drain: Perforated plastic pipe (3 to 4 inches) that goes around the inside or outside perimeter of a foundation wall before backfilling, and collects and diverts groundwater 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.

 

perlite: A natural volcanic glass with a high water content that is heated-expanded to create a lightweight aggregate used in fire-resistant insulation.

 

perm: A measure of water vapor movement through a material in grains per square foot per hour per inch of mercury difference in vapor pressure.

 

permanently installed: Fixed in place by screws, bolts, nails, etc., as distinct from components, systems and appliances considered portable or freestanding.

 

photo-oxidation: Oxidation caused by exposure to ultraviolet rays from the sun.

 

physical deficiency: A major defect, a significant deferred-maintenance item, a component or system that has exhausted most or all of its remaining useful life (regardless of its actual life expectancy), a safety concern, or anything that could potentially cause the need for an expensive repair.

 

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

 

pier block: A concrete block used to support foundation members, such as posts, beams, girders and joists.

 

pigment: A powdered solid in suitable degree of subdivision for use in paint or enamel.

 

pigtail (electrical): The electric cord that the electrician provides and installs on an appliance, such as a garbage disposal, dishwasher, or range hood.

 

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

 

pilot light: A small, continuous flame in a hot water heater, boiler or furnace that ignites gas or oil burners when needed.

 

pitch: (1) The incline slope of a roof, or the ratio of the total rise to the total width of a house. For example, an 8-foot rise and 24-foot width is a 1/3-pitch roof. Roof slope is expressed in the inches of rise per foot of run. (2) Coal tar pitch.

 

pitch pan: A container formed of sheet metal installed around supporting connections for roof-mounted equipment and machinery. Filling the container with pitch or plastic roof cement helps seal out rainwater even under conditions of vibration caused by the machinery's operation or other factors.

 

plaster grounds: Strips of wood used as guides or strike-off edges around window and door openings and at the base of walls.

 

plastic roof cement: Used as a waterproofing medium to quickly stop roof and other leaks in new construction and for general-purpose exterior repair and maintenance. Available in both summer and winter grades.

 

plat: A map of a geographical area as recorded by the county.

 

plate: Sill plate: a horizontal member anchored to a masonry wall. Sole plate: the bottom horizontal member of a frame wall. Top plate: the top horizontal member of a frame wall that supports ceiling joists, rafters, and/or other members.

 

plate line: The top horizontal line of a building wall upon which the roof rests.

 

platform framing: A system of framing a building by which the floor joists of each story rest on the top plates of the story below or on the foundation sill for the first story, and the bearing walls and partitions rest on the subfloor of each story. One story usually constitutes a platform. Also called platform construction.

 

plenum: An air compartment or chamber that connects one or more ducts and forms part of an air-distribution system for moving air under a slight positive pressure.

 

plumb: Exactly perpendicular; vertical.

 

plumb bob: A conical lead weight attached to a string used in determining plumb and elevations.

 

plumbing boots: Metal saddles used to strengthen a bearing wall/vertical stud(s) where a plumbing drain line has been cut through and installed.

 

plumbing ground: The plumbing drain and waste lines that are installed beneath a basement floor.

 

plumbing jacks: Sleeves that fit around drain and waste vent pipes and nailed to the roof sheeting.

 

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 the final plumbing inspection, including installing all toilets (water closets), hot water heater and sinks, and connecting all gas pipe to appliances, the disposal, dishwasher, and all other plumbing items.

 

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

 

ply: Denotes the number of thicknesses or layers of roofing felt, veneer in plywood, and any finished piece of similar materials.

 

ply sheet: A layer in built-up roofing.

 

plywood: A piece of wood made of three or more layers of veneer joined with glue, and usually laid with the grain of adjoining plies at right angles. An odd number of plies is typically used to provide balanced construction.

 

pocket: A three-sided, U-shaped opening in a sash or frame to receive glazing infill (differing from a rabbet, which is a two-sided, L-shaped section used with a face-glazed window sash). Also called a channel.

 

point load: A point where a bearing/structural weight is concentrated and transferred to the foundation.

 

pointing: The process of filling joints between masonry units, bricks, etc., with mortar.

 

polymer: Natural and synthetic compounds consisting of large molecules that have been formed from smaller molecules of similar make-up and used in the manufacture of plastics, concrete, glass and rubber.

 

polysulfide sealant: A type of polymer sealant which is mercaptan-terminated, having long-chain aliphatic polymers containing disulfide linkages. It can be converted to rubbers at room temperature without shrinkage upon the addition of a curing agent.

 

polyurethane sealant: An organic compound formed by the reaction of a glycol with an isocyanate and used as an adhesive and for sealing and waterproofing decks, wood flooring, trim, etc.

 

polyvinyl chloride: See PVC.

 

ponding: The development of a large puddle or area of standing water on a roof for prolonged periods due to poor drainage and/or deflection of the deck.

 

pop rivets: Fasteners used to join pieces of metal that are installed by either compressed-air-assisted or hand-operated guns; unique in that they are installed from one side of the work.

 

Portland cement: A mixture of certain minerals which, when mixed with water, form a gray-colored paste and cure into a very hard mass.

 

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

 

post-and-beam construction: The most common type of wall framing; a building method that uses posts that carry horizontal beams on which joists are supported.

 

pot life: The time interval following the addition of an accelerator before a chemically curing material will become too viscous to apply satisfactorily. See also shelf life.

 

potable: Describes water that is safe to drink.

 

powder coat: A technique for applying paint to metal surfaces. The metal is covered with a powder of dry paint particles and is baked in an oven. This causes the powder to melt and harden into a tough finish.

 

power: The energy rate, usually measured in watts. Power equals voltage times amps, or W = E x 1. The heavier the flow of amps at a given supply, the higher the rate at which energy is being supplied and used.

 

power vent: A vent that includes a fan to speed up air flow, often installed on roofs.

 

pre-shimmed tape sealant: A sealant having a pre-formed shape containing solids or discrete particles that limit its deformation under compression.

 

precast concrete: Concrete building components that 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 drop: The loss in pressure due to friction or obstruction in pipes, valves, fittings, regulators and/or burners, and the length of pipes and the number of elbows.

 

pressure regulator: A device placed in a gas line for reducing, controlling and maintaining the pressure downstream of the device.

 

pressure tank: A tank used in conjunction with a well in order to maintain pressure.

 

pressure-reducing valve: A valve installed in the water service line where it enters the building to reduce the pressure to an acceptable, desirable rate (40-55 psi).

 

pressure-relief valve: A valve that relieves excess pressure in water storage tanks.

 

pressure-treated lumber: Lumber that is treated in such a way that sealer is forced into the pores of the wood to add strength and durability.

 

primer: A material of relatively thin consistency that is applied to a surface for the purpose of creating a more secure bonding surface and to form a barrier to prevent the migration of components. Also, the first coat of paint in a paint job that consists of two or more coats.

 

priming: Sealing of a porous surface so that compounds will not stain, lose elasticity, shrink excessively, etc., because of loss of oil into the surround.

 

projection: In roofing, any object or equipment that pierces the roof membrane.

 

property survey: A survey conducted to determine the boundaries of a property.

 

protection board: In roofing, heavy asphalt-impregnated boards that are laid over bituminous coatings to protect against mechanical damage.

 

pump mix: A special concrete mix that has smaller rock aggregate than regular concrete mix and is used in a concrete pump.

 

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 cement made of whiting and boiled linseed oil that is beaten or kneaded into the consistency of dough and used in sealing window glass in sashes, filling small holes and crevices in wood, and similar purposes.

 

PVC (polyvinyl chloride): A polymer formed by the polymerization of vinyl chloride monomer (sometimes called vinyl) and widely used in residential and commercial construction because of its versatility, high strength and low cost. The white supply or drain piping made of PVC.

 

PVD (physical vapor deposition): A durable titanium or zirconium coating used on brass-finish faucets that resists tarnish, scratches and corrosion.

 

Q

​

quarry tile: A man-made or machine-made clay tile, generally 6x6x1/4-inch thick, used to finish a floor or wall.

 

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

 

quarter-sawn grain: Another term for edge grain.

 

quick-setting cement: An asphalt-based cement used to adhere tabs of strip shingles to the course below. Also used to adhere roll-roofing laps applied by the concealed-nail method.

 

R

​

R-value: The thermal resistance of insulation or a glazing system. The R-value is the reciprocal of the U-value. The higher the R-value, the less heat is transmitted throughout the insulation or glazing material.

 

raceway: An enclosed channel or conduit designed expressly for holding wires or cables.

 

radiant barrier: Intended to reduce the summer heat gain and the winter heat loss. In new homes, you may see foil-faced wood components at the roof sheathing system installed with the foil facing down into the attic. There may be other areas where the radiant barrier is integrated into the building components and structure of the home. For older homes, a radiant barrier will typically be found stapled across the bottom of some joists. All proper radiant barriers should have a low emittance of 0.1 or less, and a high reflectance of 0.9 or more. The radiant barrier should not be laid on top of the attic floor insulation, or on the attic floor anywhere, because it will soon be covered with dust and will not work.

 

radiant heating: A method of heating that consists of a forced hot-water system with pipes placed in the floor, wall or ceiling, or using electrically heated panels.

 

radiation: Describes one method of heating by which a heated surface loses heat to cooler surrounding space or surfaces. The earth receives its heat from the sun by radiation: the heat rays are turned into heat as they strike an object that absorbs some or all of the heat transmitted.

 

radiator: A heating unit that is supplied heat through a hot water system.

 

radon: A naturally-occurring radioactive gas found in soil that is heavier than air. Radon gas exposure in abnormally high levels is associated with lung cancer. Mitigation measures may involve crawlspace and basement venting and installation of various forms of vapor barriers and fans.

 

radon mitigation system: A ventilation system installed beneath the floor of a basement and/or structural wood floor designed to exhaust radon gas to the exterior of a home.

 

rafter: A sloping roof member that supports the roof covering which extends from the ridge or the hip of the roof to the eaves. A common rafter is one that runs square with the plate and extends to the ridge. A hip rafter extends from the outside angle of the plate toward the apex of the roof, and is 2 inches deeper or wider than a common rafter. A valley rafter extends from an inside angle of the plates toward the ridge of the house.

 

rafter tail: The portion of a rafter that extends past the building to form the eaves.

 

rail: Cross-members of panel doors or a sash. Also, the upper and lower members of a balustrade or staircase extending from one vertical support to another, such as a post.

 

railroad tie: Black-tar and preservative-impregnated wooden timbers that are 6x8 inches and 6 to 8 feet long that are used to hold railroad track in place. Also used as a member of a retaining wall.

 

rake: A trim member that runs parallel to the roof slope and forms the finish between the wall and a gable roof extension. The angle of slope of a roof rafter, or the inclined portion of a cornice.

 

rake edge: The overhang of an inclined roof plane beyond the vertical wall below it.

 

rake fascia: The vertical face of the sloping end of a roof eave.

 

rake siding: The practice of installing lap siding diagonally.

​

random-tab shingles: Shingles whose tabs vary in size and exposure.

 

re-glaze: To replace a broken window.

 

ready-mixed concrete: Concrete mixed at a plant or in trucks en route to a job and delivered ready for placement.

 

rebar: Nickname for reinforcing bar that is used to increase the tensile strength of concrete.

 

receptacle: An electrical outlet. A typical household has several 120-volt receptacles for plugging in lamps and appliances, and 240-volt receptacles for the range, clothes dryer, air conditioners, etc.

 

reducer: See bushing.

 

reflective glass: Glass with a metallic coating that reduces solar heat gain.

 

reflective insulation: Sheet material with one or both faces having comparatively low heat emissivity, such as aluminum foil. When used in building construction, the surface faces an air space, reducing the heat radiating across the air space.

 

refrigerant: A substance that remains a gas at low temperatures and pressure and can be used to transfer heat. Freon used in air-conditioning systems is a refrigerant.

 

register: A fixture through which conditioned air flows. In a gravity heating system, it is located near the baseboard. In an air-conditioning system, it is located close to the thermostat.

 

reglet: A horizontal slot, formed or cut in a parapet or other masonry wall, into which the top edge of counter-flashing is inserted and anchored. In glazing, a reglet is a pocket or keyway extruded into the framing for installing the glazing gaskets.

 

reinforced concrete: A combination of steel and concrete using the best properties of both. The steel consists of rebar from 3/8-inch to 2-1/4 inches in diameter and is placed before the concrete is poured.

 

reinforced masonry: Masonry units, reinforcing steel, grout and/or mortar combined to act together to strengthen a 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).

 

relative humidity (RH): The amount of water vapor in the atmosphere expressed as a percentage of the maximum quantity that could be present at a given temperature. The actual amount of water vapor that can be held in space increases with the temperature.

 

release tape: A plastic or paper strip that is applied to the back of self-sealing shingles designed to prevent them from sticking together in the bundles; need not be removed for application.

 

remote: Remote digital readouts that are installed near the front of a house that allow utility companies (electrical, gas, water) to easily read the homeowner's usage of the service.

 

removable: Capable of being opened, dislodged or transferred to another location easily.

 

replacement air: Air deliberately brought into a structure to compensate for the air being consumed or expelled.

 

repoint: To repair the mortar of masonry joints, such as between the bricks of a chimney, etc.

 

resilient flooring: A durable floor covering that has the ability to resume its original shape.

 

resistance: The internal structure of wires in conductors opposes the flow of electric current and converts some current into heat. This internal, friction-like effect is called resistance and is measured in ohms. Resistance equals voltage divided by amperage.

 

resorcinol glue: A glue that is high in both wet and dry strength and resistant to high temperatures, and used for gluing lumber and assembly joints that must withstand severe service conditions.

 

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

 

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

 

ribbon: A 1x4-inch board let into the studs horizontally to support ceiling and second-floor joists. Also called a girt.

 

ridge: The horizontal line at the junction of the top edges of two sloping roof surfaces.

 

ridge board (ridgeboard): The horizontal support board placed on edge at the ridge of a roof into which the upper ends of opposing rafters are fastened.

 

ridge cut: The end cut on a rafter that fits to the ridgeboard.

 

rigid metal conduit: Conduit that resembles plumbing pipe and encloses wires to protect them from exposure, weather and damage.

​

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.

 

roll roofing: Refers to asphalt roofing material composed of an organic felt or fiberglass mat, saturated with asphalt, and faced with stone aggregate, and supplied in 36-inch wide rolls with 108 square feet of material. Weights are generally 45 to 90 pounds per roll. Inexpensive and commonly used on sloped roofs in North America.

 

roll, rolling: To install the floor joists or trusses in their correct place. (To roll the floor means to install the floor joists).

 

Romex®: Brand name for a cable consisting of two or more insulated conductors having an outer sheath of moisture resistant, non-metallic material. The conductor insulation is rubber, neoprene, thermoplastic or a moisture-resistant, flame-retardant fibrous material. Comes in NM and NMC types.

 

roof assembly: A system designed to provide weather protection that includes the roof covering, underlayment, roof deck, insulation, vapor retarder and interior finish.

 

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

 

roof vent pipe flashing: Used in residential and commercial applications where a watertight seal of roof penetrations around plumbing vent pipes is installed. The flashing material can be made of sloped plastic and metal bases with flexible rubber sealing collars.

 

roofing tape: An asphalt-saturated tape used with asphalt cements for flashing and patching asphalt roofing.

 

root cellar: Historically, a food storage area located within a basement or by itself beneath a home, possibly with a dirt floor and separate exterior exit.

 

rough flooring: Floor sheathing; materials used to form an unfinished floor.

 

rough opening: The opening in a wall into which a door or window is to be installed.

 

rough plumbing: All plumbing that is done before the finish trades (sheetrock, painting, etc.), including all waste lines and supply water lines that are in the walls or framing of the building.

 

run (roofing): The horizontal distance between the eaves and the ridge of the roof, being half the span for a symmetrical gable roof. Also, the net width of a step or the horizontal distance covered by a flight of stairs.