Pocket Door 
Sliding door, on an overhead track, which recesses into a pocket in the wall when opened. 

Podium
1. A low wall that serves as a pedestal or foundation. 
2. A continuous bench projecting from the walls of a room.
3. A low, raised platform or pulpit used by speakers, conductors, etc. 

Point of Curve 
Term used by surveyors to denote the beginning of a curve. 

Point of Diminishing Return 
Point at which addition units of a specific resource no longer cause the level of satisfaction that was previously attained. 

Point of Intersection 
Engineering or surveying term, also called the vertex, which denotes the point where two tangents to a curve meet. 

Point of Tangent 
Term used by surveyors to denote the end of a curve, which extends from the point of curve to the point of tangent.

Pointed Ashlar 
Tool marks that have been made on the face of the squared stone that is used in building facings, foundations, sidewalks, etc. 

Pointing 
Mortar placement or replacement into masonry joints, which is done after masonry, is laid in place. 

Pointing Trowel 
Triangularly shaped, small trowel used to finish mortar joints. 

Points 
Fees paid to induce lenders to make a mortgage loan. Loan service charge equals 1% of the amount of the loan principal and must be paid up front. It is a one-time charge that has the effect of reducing the amount of money borrowed. 

Polarity
The direction indicating positive or negative electrical charges flowing through a circuit. Direct current has two poles, one positive, one negative, flowing from negative to positive. 

Polarized Plug 
Electric plug that guarantees that the hot side of a receptacle is connected to the hot side of an appliance because it can be inserted into the receptacle only one way. When the appliance switch is off, the power to the appliance stops at the switch. 

Pole 
Calculation of the amount of hot wires connected to an electrical circuit breaker; single pole has one, double pole has two. 

Pole Gun 
Extension handled spray gun for paint, which permits high areas to be reached. 

Police Power 
The right of any governmental body to enact and enforce regulations for the order, safety, health, morals and general welfare of the public. 

Policy
A real estate owner's rules regarding the use of the property by a tenant. A principal plan or course of action. Alternately, a written contract in which one party guarantees to insure another against a specified loss. 

Polish Coat 
Final coat of joint compound when tape is installed over drywall seams. 

Polishing Bonnet 
Used alone or with a wax, this sheepskin or cloth cover goes over a motor wheel to polish surfaces.

Polybutene Tape 
Mastic type of tape, used to seal windowpanes, which is non-hardening. 

Polyethylene
Thermosetting plastic, which when used as tubing, is flexible and easy to work with. It is also corrosion resistant so that it can be used to transport chemicals. Since it is also resistant to deterioration upon exposure to ultraviolet light, it can be used for exterior purposes, unlike PVC which must be protectively coated. 

Polygon
A closed plane figure with more than four sides and angles. 

Polymerization 
Chemical reaction which joins two or molecules to form a more complex molecule whose molecular weight is a multiple of the original and whose physical properties are different, which is used when manufacturing silicon resins, acrylic resins, polystyrene resins, etc. 

Polystyrene 
Plastic manufactured as clear sheets, foam beads or foam boards, which are formed from the polystyrene foam beads expanding with heat in a mold. Insulating board has a high R-value, or thermal resistance. For this reason, it is often used as roof deck sheathing.

Polysulfide 
Synthetic rubber-like substance used as caulking or sealing for gaskets. It is weather and chemical resistant in both solid and liquid forms. 

Polytetrafluoroethylene
Teflon type material with good heat and chemical resistance. 

Polyurethane 
Polymer plastic most often found in paint, varnish, and insulating foam. The rigid board form has high thermal resistance, while the liquid foam is pressurized, permitting the foam to be directed into small spaces. 

Polyurethane Foam 
Board Insulating board that has a higher R-value per inch thermal resistance than fiberglass batting and, consequently, takes up less space. 

Polyvinyl Acetate Glue 
White, non waterproof, glue which forms a very strong joint for use in non-humid and indoor use. 

Polyvinyl Chloride 
Thermoplastic polymer, formed from vinyl chloride, which is made into plumbing pipes and fittings. 

Polyvinyl Chloride (PVC) Pipe 
Polyvinyl chloride, a lightweight, resilient, chemical resistant, strong and durable thermoplastics, with an long lifespan, made into piping which is often used for cold water systems and where chemicals are found. There is bell and spigot pipe, with a bell on one end, which has an internal elastomer seal to hold the lubricated plain end of the next piece of pipe, by making a fluid-tight joint. Solvent cement joint pipe joins the ends by applying a primer to soften the surface of the material, with the solvent cement being applied to the pipe end and the inside of the fitting end, then inserting the pipe into the fitting using a twisting motion to spread the solvent cement. The cement cures rapidly and the joints fuse together. 

Pond
Incompletely drained roof surface. 

Ponding
1. Accumulation of water that doesn't ever completely drain off a surface, which is caused by not having a proper slope or having depression in the surface. 
2. To cure concrete by covering the surface with water. 

Pony Trowel 
Small, motor driven, power trowel, which can be used to finish concrete. 

Popcorn
1. Decorative acoustic ceiling, spray on texture, consisting of vermiculite in a bonding agent.
2. Asphalt paving mix consisting primarily of ¾ inch aggregate. 

Pop Rivet 
Rivet, used to fasten two parts together, which consists of a metal sleeve with a flange on one end and a center stem, which fits into the sleeve. The stem is broadened at the end so that it forces itself against the end of the sleeve. When the sleeve and stem are put into the hole that has been drilled through both pieces, the sleeve flange is even with the outside of the hole. A riveting tool grabs hold of the stem protruding out if the flanged end of the sleeve, while it is holding the sleeve in the hole, and then pulls the stem. The pulling force on the stem creates pressure on the sleeve, causing it to collapse and expand against the surface around the hole. The pieces are held tightly between the flange on one side and the expanded sleeve end on the other. The stem "pops" off, inside the sleeve, during the pulling process. 

Pop Riveter 
Tool which is used to install pop rivets. 

Poppet
Valve, controlling flow, which has a disc at a right angle to the stem, with the valve opening and closing when it is moved up and down on the end of the stem and is often used in internal combustion engines. 

Population Density 
Population per square mile of a given area.