P - Technical Dictionary


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.

PC Item                                                     
See Prime Cost item.

PCB                                                           
Any of a family of industrial compounds produced by chlorination of bi-phenyl, noted primarily as an environmental pollutant that accumulates in animal tissue with resultant pathogenic and teratogenic effects.Short for polychlorinated biphenyl. Any of a family of very stable industrial compounds used as lubricants, heat-transfer fluids, and plasticizers. The manufacture and use of PCBs has been restricted since the 1970s because they are very harmful to the environment, being especially deadly to fish and invertebrates, and stay in the food chain for many years.

PVC                                                           
Poly Vinyl Chloride. The material used for flexible (or rigid) glazing gaskets and weatherseals. Flexibles are soft and can take up variations in tolerances within the window.

Paint Primer                                              
The first, base coat of paint when a paint job consists of two or more coats. Its job is to provide long-term adhesion to the specific substrate as well as providing a surface to which the rest of the system can be applied.

Paint Sealer                                               
A paint coating that treats a fault or condition in a substrate in such a manner as to render it suitable for a further coating application.

Paint Primer                                              
The first, base coat of paint when a paint job consists of two or more coats. Its job is to provide long-term adhesion to the specific substrate as well as providing a surface to which the rest of the system can be applied.

Paint Sealer                                               
A paint coating that treats a fault or condition in a substrate in such a manner as to render it suitable for a further coating application.

Paint Undercoat                                        
A coating applied prior to the finishing or topcoats of a paint job. It may be the first of two or the second of three coats. Its job is to provide build; fill small.

Palings                                                       
Broad, split or sawn, upright timbers of a fence, e.g. pickets.

Palladian Form                                          
Refers to a building having a central block connected by linking building on each side.

Palladian Style                                         
A classical style of architecture and decoration based on the work of the Venetian architect Andrea Palladio (1508-1580). The style featured very large and dramatic pediments, cornices and sculptured ornaments of eagles, scallop shells, and other motifs.

Palladian Window                                     
A triple opening; the center opening is usually the widest. A main window with an arched head and a long narrow window on each side with a square head.

Palmett'o                                                   
A name for several kinds of palm tree, notably Sabal and the only European palm Chamaerops.

Palmette                                                    
A classical decorative motif based on the fan-like shape of a palm leaf. It was widely used as ornament on Neo-classical furniture in the late 18th century.

Pan                                                            
The flat portion between the ribs in a pan-type preformed sheet.

Panelled Door                                           
A door with sunk or raised panels set in its frame. Traditionally such panels were edged with decorative mouldings.

Panelling                                                    
The covering of an interior surface with timber, usually as a series of sheets fixed between framing members, called wainscoting if limited to the lower part of the wall.

Panic Hardware                                        
A door-latching assembly incorporating a device that releases the latch upon the application of a force in the direction of egress travel.

Paper Space/Model Space                      
Paper Space is a crucial part of the AutoCAD system. It is a method whereby the pure design-based linework can easily be integrated into neat scaled official drawings incorporating titleblocks, company logos etc.
Model Space - Model space is basically "the real world". When working in model space, no thought should be given to how the drawings shall appear coming out of the printer. Everything is drawn at a scale of one to one (where meters, millimeters or inches are the preferred drawing units) and all drawing componants are positioned at the correct distances from each other, regardless of what sheet of paper they may end up being printed on. The drawings may also be positioned on a specific coordinate system, such as a national mapping grid, in order to integrate accurately with other drawings.
Paper Space - Paper space is only entered come printing time. A typical paper space layout will consist of a standardised title block containing information about the drawing; drawing number, date completed etc. This title block will be drawn to accurately fit on a standardised sheet of paper. For example, a sheet of ISO A1 measures 841mm by 594mm. Thus, a titleblock for printing on such a sheet may measure 820 drawing units by 570. It can then be printed out at a scale of 1 to 1, and will fit on the page nicely.
Viewports - All this is of course well and good, but how do we get the actual drawing information from model space into this titleblock? To do this, we utilise an item known as a viewport. A viewport is a shape (usually a rectangle but can be any shape) that is drawn into paper space. Think of them as a TV screen. Inserting a viewport into paper spaces "places a camera" into model space. You can change the angle of view, the scale factor and many other variables in the viewport settings. These changes only effect this one viewport. This lets you have, for example, one large viewport of a building site at a scale of 1:100, and right beside it another showing a detailed area at a scale of 1:10. It's the same building site, and it exists only once in model space, but it is represented twice in two different ways in the final drawing. The obvious advantage of this is any changes made in model space will instantly update in every viewport, keeping all your printable drawings up to date.

Parametric                                                
Controlled by parameters.

Parapet                                                      
A wall built up higher than the line of a roof, to hide the roof surface or curtail the spread of fire. Also, a low wall providing safety for users of a flat roof or bridge.

Parget                                                        
To plaster over; to cover with ornamental plasterwork; to decorate the surface of; to bedaub, plaster spread over a surface; cow-dung plaster for chimney flues; ornamental work in plaster; surface decoration. A bonding agent used to attaché termite mesh.

Parkway                                                    
A highway that passes through open spaces (and in Australia, bushland, for example the Tuggeranong Parkway in Canberra).

Particle Board                                           
A plywood substitute made from coarse sawdust and resin pressed into sheets.

Partition                                                     
Non-load bearing units, extending from floor to ceiling or part way, subdividing space.

Partition Wall                                             
A wall that subdivides spaces within any story of a building or room.

Party-Wall                                                 
A separating wall that divides two attached residence rooms as a firewall.

Passage                                                    
A space connecting one area or room with another.

Passive Solar                                            
A solar heating system that operates on natural thermal processes, and uses no external mechanical power to move the collected heat. Generally, the building's structure itself forms the solar

Path                                                           
An exterior prepared surface for pedestrian use, including pedestrian areas.

Patient-Care Area                                    
Includes “ward areas” and “treatment areas”.

Patina                                                        
Fine sheen on the surface of furniture or metal that results from years of handling and the gradual build-up of dirt and polish.

Patio                                                          
A large paved outdoor living area.

Patterned Glass                                        
Glass passes through patterned rollers to form ribbing and pebbling.

Paver                                                         
Materials, commonly masonry, laid down to make a firm, even surface.

Pavilion                                                      
A peaked tent or similar light ornamental building. A self contained part of a building usually flanked by a central block.

Pedestal                                                    
A support or base for increasing the height of a column or statue.

Pedestal Table                                          
A round or square table standing on a single central pillar or column mounted on a polygonal base, generally with three or four feet.

Pedestrian (Zebra) Crossing                     
A portion of carriageway marked by a series of longitudinal bars placed parallel with the road centre-line together with the relevant signage.

Pediment                                                   
A triangular section of wall above the cornice. A triangular gable across a portico, door or window; any similar triangular decorative piece over a doorway.A decorative feature, often triangular in shape, edging the gable and surmounting the entablature of a classical building.

Pedimental                                                
A wide, low-pitched gable surmounting the facade of a building in a Greek style.A triangular element, similar to or derivative of a Grecian pediment, used widely in architecture and decoration.

Pelmet                                                       
A decorative framework to conceal curtain fixtures at the top of a window casing.

Pembroke Table                                        
Small table, that has two frieze drawers, two drop leaves, and is usually on legs with castors. It was made in England from the mid 18th century.

Penetration                                                
A projection through the roof, e.g. vent pipe, chimney or roof light.An opening in a concrete slab or concrete wall that is not a window or door. Slang: Peno

Peno                                                          
A short way of saying penetration.People with Ambulant Disabilities People who have a mobility disability but are able to walk.

Perennial                                                   
A plant that lives more than two years. Lasting through the year; perpetual; never failing; growing constantly; lasting more than two years (botany); (of insects) living more than one year.

Performance                                             
The way in which something reacts under certain conditions or fulfils the purpose for which it was intended.

Performance Requirement                       
User requirement expressed in terms of the performance of a product.

Performance Specification                       
Document which specifies functional requirements of a construction, and which is normally separate for construction and installation works. States the results which are to be achieved, giving the contractor total freedom in the choice of materials and methods.

Pergola                                                      
An open trellis like frame attached to a building and / or supported by posts - used for climbing plants.

Permanent vent                                        
A part of the window that provides ventilation even when the sash is in the closed position.

Permavent Window                                   
A part of the window that provides ventilation even when the sash is in the closed position. A permanent vent in a window

Perspective Drawing                                 
Drawing which shows a three-dimensional view of a project in which one or more groups of projectors converge on their respective vanishing points.

Phased Construction                                
A unit approach to construction or design and construction. Each phase or element has a defined work scope and can be considered a separate project with design and construction phases overlapping.

Pickets                                                      
Thin verticals in a fence - often with decoratively shaped tops and usually of sawn timber.

Pictogram                                                  
A graphical composition that may include a symbol plus other graphic elements, such as a border, background pattern or colour that is intended to convey specific information.

Picture Rail                                                
A horizontal moulding fixed to the walls below the ceiling height and shaped to take metal hooks from which to hang art and photos.

Pier                                                            
A solid masonry support more massive in proportion than a column. An engaged pier is one that is bonded into a wall for extra strength and usually wider than it is deep.

Pier Table                                                  
A small table, disproportionately tall, made to stand against a pier (generally between two windows).

Pierce-Fastened                                        
A method of fixing cladding by means of a screw or nail which pierces the cladding.

Pilaster                                                      
A rectangular shaft attached to a wall; often treated like a classical column. An architectural term for a flattened column attached to the surface of a piece of case furniture as a piece of decoration, rather than for support. Pilasters usually flank cupboard doors or drawers, and are often capped with capitals.

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

Pin connection                                         
In two dimensions, a pin connection restrains two translation degrees of freedom but does not restrain rotation. Since the rotation degree of freedom is unrestrained at a pin connection, it transfers no moment.

Pipe Staunchion                                        
A load bearing pipe support used between two windows.

Pisé                                                           
Rammed earth or clay for walls or floors.

Pitch                                                          
The slope of a roof.

Plan                                                           
View, section or cut, in a horizontal plane, seen from above.

Plan Detail                                                 
Drawing which to a large scale shows a part of a plan.

Plan View                                                  
Drawing of a structure with the view from overhead, looking down.

Plans                                                         
Approved Contract drawings showing the location, type, dimensions, and details of Contract work to be performed

Plant                                                          
Machinery and heavy equipment installed for the operation of a service, eg. heating and ventilating service. Implements, machines and other items employed in construction work.

Plant Room                                               
A mechanical services room.

Plastics                                                      
A loose term used to designate a wide range of substances which are capable of being moulded. Commonly made from petroleum products.

Plate                                                         
Normally a frame member that lays horizontally within a framed structure, such as:Bottom 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 cavity created between an actual ceiling and a suspended ceiling, which is often used for placing building services such as heating and air conditioning ducts. It can also be used for electrical, telephone and network wires.

Plinth                                                         
A projecting base of a column, walls or pedestal which may be made of a more durable material A raised slab or solid platform below a large piece of equipment to lift them above floor level to enable easy cleaning.

Plotting                                                     
Output of a CAD drawing to paper or film using a plotter.Plumb To make perpendicular In a perpendicular position The term often used to describe a vertical element, perfectly perpendicular, to a level surface above or below.

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

Plywood                                                    
Sheets or panels formed by bonding together two or more plies cut from solid timber.

Poignant                                                    
Stinging, pricking; sharp; acutely painful; penetrating; pungent; piquant; touching, moving, exciting pathos. For additional definitions, see Nigel.

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

Pointing                                                     
The finished mortar treatment of bricks and masonry joints.

Political Correctness                                 
The avoidance of expressions or actions that may be understood to exclude or denigrate groups or minorities traditionally perceived as disadvantaged by eg race, sex, disability, class, political alignment or sexual inclination; the use of recommended alternative expressions intended to be non-discriminatory. Originally US.

Polychrome                                               
Two-coloured, usually applied to brickwork. Also called dichromatic.

Polygon                                                     
A complex object composed of three or more straight lines in a closed figure.

Polyline                                                      
A complex object composed of two or more lines, curves, or arcs, which have contiguous endpoints. A closed polyline or polygon has its endpoints joined into a closed form.

Polyvinyl Chloride                                    
(PVC) A type of plastic. In its plasticised form PVC contains a range of softeners including a range of chemicals known as Pthalates. There are upstream OH&S and environmental issues and downstream disposal issues as very few recycling opportunities exist. Issues mostly surround problematic and persistent chlorinated organic compounds.

Ponding                                                    
Pooling of undrained water on a surface.

Pop Art                                                      
In this return to representational art, the artist returns to the world of tangible objects in a reaction against abstraction. Materials are drawn from the everyday world of popular culture—comic strips, canned goods, and science fiction.

Porch                                                         
A building forming an enclosure or protection for a doorway; a portico or colonnade; a veranda (US); the Stoic school of philosophy, from the Painted Porch in the Agora of Athens where Zeno taught. [Old French porche, from Latin porticus, from porta a gate]

Porte-Cochère                                          
A drive through and covered temporary stopping location to allow pick-up or disembarking of persons and for them to enter a building under cover. A house entrance admitting a carriage. [French porte, from Latin porta gate, and French cochère, feminine adjective from coche coach]

Portico                                                       
A covered walkway or entrance to a building, often having a row of columns supporting the roof.A series columns or arches in front of a building, generally as a covered walkway. Entranceway to a church, often bordered by columned masonry. A colonnaded entrance space or doorway. An open porch with columns supporting a pedimental roof, creating the entrance and or centre piece of a facade

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

Post                                                           
A vertical framing member usually designed to carry a beam.

Post-Tension Concrete                            
A method of pre-stressing reinforced concrete in which tendons are tensioned after the concrete has hardened.

Post-and-Beam                                         
A basic building method that uses just a few hefty posts and beams to support an entire structure in contrast with stud framing

Potable Water                                           
Water that is suitable for human consumption, food preparation, utensil washing and oral hygiene. Sometimes referred to as drinking water.

Pre-Selection                                            
The establishment of a list of contractors with suitable experience, resources, ability and desire to execute a project, bearing in mind the character, size, location and timing of the project.

Preferred Term                                         
Term recommended by an authoritative body.

Prefinished Wall Panels                            
Predecorated sheets or thermosetting laminated sheets that are designed for use as the final wall finish of the wet area

Preliminary Drawing                                  
Drawing of a designer's concept of a project and which is expected to be modified.

Premises                                                   
Space or property made available to the contractor for constructing the work.

Preparation                                                
Work necessary before an activity is undertaken. "Preparation" occurs at the interface between Work Sections and may be the first or last activity of the Work Section to be carried out, depending upon the project specification.

Prepared Opening                                     
An opening in a building made prior to the installation of the window.

Preservation                                              
The process of applying measures to sustain the existing form, integrity, and material of a building or structure and the existing form and vegetative cover of a site.

Pressure Seal                                           
A durable, mechanical fastening system that applies continuous pressure to the exposed edge of the membrane and has a profile suitable for the application of a gasket between the pressure seal and the substrate.

Preventive Maintenance                          
The Activities performed to retain an item in a specified condition by providing systematic inspection, detection and prevention of incipient failure. Preventive Maintenance is normally programmed.

Prime Cost Item                                        
An amount of money included in a contract for a particular item yet to be selected. Used mostly for retail items selected by the proprietor such as refrigerators, ovens, dishwashers, tiles, mirror, toilet pan, taps, etc. The actual cost is then substituted for the PC item amount.

Primitive                                                    
The simplest drawing entities from which all objects are built. Common primitives include: point, line, circle, arc, and ellipse.

Product Data                                             
Illustrations, standard schedules, performance charts, instructions, brochures, diagrams and other information furnished to illustrate materials or equipment for some portion of the Work.

Product Manual                                         
The documentary information prepared by the designers for the builders containing PRODUCT DATA for a particular project.

Product or Products                                  
A generic term which specifically includes raw materials, processed materials, components, parts, sub-assemblies, systems, and subsystems.

Professional Liability Insurance                
Insurance that covers suits against the insured for such damages as injury or death to others, property damage, and the like. Usually applies to the design professional.

Project Management                                
A process to administrate and manage an entire project on behalf of an owner; sometimes begins defining project requirements, property appraisal and acquisition, total budget planning, project planning and design, establishing a QA and QC program, exercise manpower, resource, and expenditure efficiencies, operational procedures, securing bids, to bestow or recommend contract award, coordinate construction contracts, oversee cost control, monitor scheduling, inaugurate the commissioning process, and perhaps initiate rental occupancy.The project management activity may involve the services of a construction manager to administer and coordinate the actual construction activity. Project management is akin to the ancient 'master builder' concept.

Proportion                                                  
he relationship of the size of parts of a building to each other and to the whole.

Proscenium Wall                                       
A wall within a theatre or public hall which divides the stage from the audience.

Protection Board                                       
A durable material used to overlay the membrane to protect it from physical damage. Timber and timber based products are not acceptable.

Provide                                                      
Provide means to supply and install.

Provisional Quantity                                  
A quantified item in the tender documents, for inclusion in the tender, which is unable to be measured accurately at tender time but for which a rate is required and will be used to adjust the contract sum when the actual quantity becomes known.

Provisional Sum                                        
A sum nominated in the tender documents for work anticipated but insufficiently designed or detailed at the time of tendering. The sum is then adjusted as a contract variation once the extent of the work is defined.

Public Use                                                 
Interior or exterior rooms, spaces, or elements that are made available to the public. Public use may be provided at a building or facility that is privately or publicly owned.

Public Way                                                
Any street, alley or other parcel of land open to the outside air leading to a public street, which has been deeded, dedicated or otherwise permanently appropriated to the public for public use.

Purlin                                                         
A longitudinal structural member in a roof. Purlins support the loads from the roof deck or sheathing. They are supported by the principal rafters or building walls (or both).

Pylon                                                         
Pylon, noun a structure for supporting power-cables; a gateway, gate-tower, gatehouse or building through which an entrance passes, especially the gateway of an Egyptian temple.

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