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
Calcium Carbonate or Efflorescence

A white chalky material which is very often found on concrete basement walls and other concrete surfaces where water has leached some of the chemicals out of the concrete. Usually a sign of past or present moisture penetrations.

See also: Q&A: Basements and Crawl Spaces

Carbon Monoxide (CO)

A toxic colorless and odorless gas and common combustion by-product. CO testing must be a regular part of the annual gas furnace service. Combustion appliances including: furnaces, fireplaces, grills, generators, gas water heaters etc. require proper installation and service in order to prevent CO exposure.

Caution! Don't be the victim of CO poisoning! CO can and does kill people!

  • Have your gas furnace serviced every year!
  • Don't burn charcoal or charcoal briquets indoors!
  • Don't allow the exhaust from motors to enter your home! (pool heaters, generators, cars in the garage)
  • Don't leave your car engine running inside your garage. If you need to heat up the car, move it out of the garage to do so!

Casement Window

A window with hinges on one of the vertical sides and swings open like a normal door.

See also: Topics: Replacement Windows, Q&A: Windows and Skylights


A flexible material used to seal a gap between two surfaces e.g. between pieces of siding or the corners in tub walls.

Caulking is Great, but it's not Magic!

Caulking and roof patching materials are wonderful products but they can also cause problems. For example: most roofing and siding systems are designed to shed water from one surface to another. Ridge caps drain onto shingles, one shingle drains onto a lower shingle, metal flashing moves water from the chimney onto the roof, etc. When caulking is used to "repair" a defect, it must be used in conjunction with the system in place. In most cases, the defective part needs to be repaired or replaced, only then can caulking be used as a secondary level of protection.

If caulking or roof patching products are used incorrectly, they can nullify the original design and cause leaks and other problems. Such incorrect usage often results in preventing water from properly shedding from one surface to another. It can result in the water being wicked sideways or even up and under surfaces.

See also: Q&A: Bathrooms

Change Order

A written document which modifies the plans and specifications and/or the price of the construction Contract.

See also: Topics: A Building and Remodeling Checklist

Chip Board

See "Oriented Strand Board."

See also: Q&A: Framing, Q&A: OSB vs. Plywood

Circuit Breaker

A device which looks like a switch and is usually located inside the electrical panel or circuit breaker box. It is designed to (1) shut of the power to portions or all of the house and (2) to limit the amount of power flowing through a circuit (measured in amperes). '110' volt household circuits require a fuse or circuit breaker with a rating of 15 or 20 amps. '220' volt circuits may be designed for higher amperage loads e.g. a hot water heater may be designed for a 30 amp load and would therefore need 30 amp fuses or breaker. See also GFI.

See also: Q&A: Electrical, Topics: Electrical Systems

Circulator Pump

An electric pump that circulates hot water in radiant heating systems. Sometimes used to provide for 'instant' hot water to bathrooms and showers.

The use of circulator pump to move hot water from a boiler, water tank or tankless water heater is a wonderful way to create energy efficient radiant heat to one or more areas of the house. Using such a pump to provide 'instant' hot water to various faucets can consume a great deal of energy unless the pump is equipped with a timer. Such a timer must be in easy reach in order to be set to run during the times of most likely hot water usage.


A common construction material often used for foundations, ground level floors, and sidewalks. Most concrete is made out of (1) Portland cement, (2) sand, and (3) gravel or aggregate. It is commonly reinforced with steel rods (rebar) or wire screening (mesh).

See also: Q&A: Concrete For Building Material, Q&A: Refinishing an Old Concrete Floor

Concrete Block

A hollow concrete 'brick' often 8" x 8" x 16" in size. Often used in low rise commercial and some residential construction. The original design and use is attributed to the architect Frank Lloyd Wright.

See also: Q&A: Block vs. Concrete Foundation, Q&A: Concrete Block Stairs

Concrete Board or Wonderboard™

A panel made out of concrete and fiberglass usually used as a tile backing material.

See also: Q&A: Vinyl Coated Drywall vs. Concrete Board


Condensation in homes usually occurs when warm moist air comes in contact with a colder surface. Warm air can hold more moisture than cold air, it has a higher "dew point" than colder air. For example, when the air in a home is heated it can hold more moisture than the colder air at the outside of the home. If the warm air absorbs a great deal of moisture and then comes in contact with a cold surface, e.g. the roof sheathing, then the moisture in the warm air changes from a vapor into a liquid. It condenses. This is turn can cause all sorts of damage including fungal wood rot.

See also: Topics: Gutters, Downspouts, and Drains


A company licensed to perform certain types of construction activities. In most states, the generals contractor's license and some specialty contractor's licenses don't require of compliance with bonding, workmen's compensation and similar regulations. Some of the specialty contractor licenses involve extensive training, testing and/or insurance requirements. There are various types of contractors:

  • General contractor - Responsible for the execution, supervision and overall coordination of a project and may also perform some of the individual construction tasks. Most general contractors are not licensed to perform all specialty trades and must hire specialty contractors for such tasks, e.g. electrical, plumbing.
  • Remodeling contractor - A general contractor who specializes in remodeling work.
  • Specialty contractor - Licensed to perform a specialty task e.g. electrical, side sewer, asbestos abatement.
  • Subcontractor - A general or specialty contractor who works for another general contractor.

Q&A: Contractor Profit and Overhead, Q&A: Buying Property and Building Your Own Home, Topics: A Building and Remodeling Checklist, Topics: A Field Guide to Bad Home Repair and Remodeling Contracts

Construction Contract

A legal document which specifies the what-when-where-how-how much and by whom in a construction project. A good construction contract will include:

  1. The contractors registration number.
  2. A statement of work quality such as 'Standard Practices of the Trades' or 'According to Manufacturers Specifications'.
  3. A set of Blue Prints or Plans.
  4. A set of Specifications.
  5. Any Allowances.
  6. A construction timetable including starting and completion dates.
  7. A Fixed Price for the work, or a Time and Materials formula.
  8. A Payment Schedule.
  9. A written Warranty.
  10. A clause which outlines how any disputes will be resolved.

See also: Q&A: Construction Contracts

Cost Plus Contract

Same as "Time and Materials Contract."

Curtain Drain

A ditch sometimes filled with gravel and a drain tile which diverts storm and drain water away from a structure.

See also: Q&A: Yard Drainage

Custom or Custom Construction

This term used to mean "one of a kind", "unique" or designed and built for a specific person. It can still mean that, but it is also used to suggest that a tract construction was built to a higher standard than the average.


A condominium is a method of common property ownership (this is a functional and not a legal definition). In most cases in involved owning the land in common with all of the other unit owners. In some the structures are also owned by the condominium association and only the "interior wall surfaces" are under the direct ownership and control of the association.

Since many condominium complexes are multi unit structures, the term has been confused with a style of construction. But town-home style structures, detached single family homes, marinas and parking lots can be owned as condominiums. For example, it is possible to own a slip for a boat in a marina that is a condominium (that yacht is extra).

See: Condominiums