Glossary of Construction Terms

Do you ever feel as if your contractor is selling you polyisocyanurate foam when what you really needed was a setback thermostat? Here is a handy guide to common (and not so common) construction terms. Scroll through the glossary below or sort by the letter that starts the word you're looking for. For example, to find polyisocyanurate foam, select P and click Submit.

A (7) | B (6) | C (18) | D (8) | E (9) | F (8) | G (2) | H (4) | I (1) | J (1) | L (4) | M (3) | O (2) | P (11) | R (10) | S (19) | T (7) | U (1) | V (1) | W (4) | Z (2)
Title Definition

See Topics: Decks

Pex Plumbing

Pex stands for "crosslinked polyethylene pipe". A good substitute for copper plumbing. This is a relatively easy material to install and can be used for hot and cold water supplies and radiant heating.

George's TipsIn my work I see more and more Pex piping for water supplies and heating systems. The only problems I have seen seem to be related to the ease of installation - it's so easy to use that some folks become a bit too sloppy! - George

Pex piping

Polyvinyl Chloride PVC or CPVC

A type of white plastic pipe sometimes used for water supply lines. Polyvinyl Chloride has some potentially serious toxicity problems during manufacture and disposal. I don't recommend the use of materials containing PVC such as: pipes, vinyl siding and some roofing membranes.

See also: Q&A: Copper vs. CPVC Piping

Payment Schedule

A pre-agreed upon schedule of payments to a contractor usually based upon the amount of work completed. Such a schedule may include a deposit prior to the start of work. Payments are often scheduled for the beginning of the month to allow the contractor to distribute to the subcontractors and suppliers by the 10th of the month. There may also be a temporary 'holdout' at the end of the contract for any small items which have not been completed.

See also: Topics: A Field Guide to Bad Home Repair and Remodeling Contracts, Topics: A Building and Remodeling Checklist

Percolation or Perc. Test

A test to determine if the soil on a proposed building lot is capable of absorbing the liquid affluent from a septic system.

See also: Topics: Purchasing Undeveloped Land


A governmental authorization to perform a building process as in:

  • Zoning\Use permit - authorization to use a property for a specific use e.g. a factory, a single family residence etc.
  • Grading permit - authorization to change the contour of the land.
  • Septic permit - a health dept. authorization to build or modify a septic system.
  • Building permit - authorization to build or modify a structure.
  • Electrical permit - a separate permit required for most electrical work.
  • Plumbing permit - a separate permit required for new plumbing and larger modifications of existing plumbing systems.

See also: Topics: A Field Guide to Bad Home Repair and Remodeling Contracts, Topics: A Building and Remodeling Checklist, Topics: Deck, Q&A: Buying Property and Building Your Own Home


See, "Blue Print(s)"


A type of plastic pipe (often gray in color) sometimes used in domestic water supply systems. Some polybutylene plumbing systems are been recalled due to a history of leaks and failure.

See also: Topics: Consumer News

Polyisocyanurate Foam

A rigid foam board insulation often used in locations where there is not enough room for standard batt insulation. A nice word which can be used to impress or confuse someone. Programmed to various temperature settings. One of the least expensive ways to reduce energy consumption.

See also: Q&A: Insulation and Energy


A vertical framing member usually designed to carry a beam. Often a 4" x 4", a 6" x 6", or a metal pipe with a flat plate on top and bottom (see diagram).


See also: Q&A: Framing

Pressure Relief Valve

A device mounted on a hot water heater or boiler which is designed to release any high steam pressure in the tank and thus prevent tank explosions.