- Making it easier to build your home

Construction Forms

Construction Dictionary

a-c | d-g | h-m | n-r | s-z

Welcome to our online construction dictionary. The dictionary is in a continual evolution. Since this site is about residential construction the dictionary will reflect this. If you can't find a certain term email us and we will add it to our list.


header- a horizontal supporting member placed above a door or window that is used to support the weight above.

header band- see rim joist.

head room- the distance measured between the floor and ceiling. The code specifies minimum head room for different applications.

high gloss paint- paint that has high amount of luster or shine. It is easily cleaned without damaging the surface. However, it shows flaws that semi-gloss or flat paint can hide. It is often used for trim such as window casing and baseboard.

hip roof- a pyramid shaped roof where each part of the roof has an equal slope.

hold down straps- metal straps that are embedded in the foundation to hold the house to the foundation in case of earthquakes. Hold down straps are require by building codes in seismic zones 3 and 4.

hollow core door- a lightweight door that is filled with cardboard or wood fibers.

hose bib- a water faucet that is threaded to accept a garden hose.

hurricane clip- a metal fastener that attaches from the top of the exterior walls to the roof trusses. These clips help to hold the roof structure to the house under severe wind loads.

HVAC- stands for heating ventilation and air conditioning. HVAC tradesmen generally specialize in forced air systems, while plumbers specialize in hydronic heating systems.

hydration- the chemical reaction which occurs when cement and water mix. The reaction produces heat.

hydronic- heat and cooling systems that used water as a means of causing a temperature change. Hydronic baseboards are the most popular type of hydronic heating system in residential construction.


I beam- beam made in the shape of "I". Metal I beams are used in basements as girders. Wood I beams are used for joists.

Inspection- a visual survey of the work in progress or in at completed stage. Inspection are carried out by the owner or his representative to ensure compliance with the construction documents. Inspections are also undertaken by building officials for compliance with building code.

insulation- material used in construction which resists heat and sound transfer. A materials resistance to heat transfer is stated in R value. The higher the R value the better the resistance. Insulation in residential construction is often made from fiberglass, cellulose or urethane foam.

interlocking siding- siding that interlocks the top of one piece with the bottom of another allowing for hidden nailing. Vinyl, steel and aluminum siding are usually made to interlock.


jamb- the wood frame surrounding a window or door. The door hinges attach to one side jamb, the latch on the other.

joint- a connection of two pieces of material by a specified method.

joist- the structural members that are used to horizontally support the floor and ceiling. Joist are usually 2 x 6 or larger, and are laid on edge. In modern construction manufactured "I" beams are commonly used for joists because of their uniformity, and strength.

joist hanger- a metal strap that supports the end of the joist when no bearing point is present.


key- a groove placed in part of a concrete joint to make it stronger. Footings are often keyed to make a stronger joint between footing and foundation.

kiln dried- lumber is often dried in a kiln to a specified moisture content (usually 6-12%).


labeled door- a door that carries a U.L. (Underwriters' Laboratory) listed fire-rating. The fire-rating information is usually on the hinged edge. Garage person doors usually are required to have a minimum of a 20 minute fire rating.

laser-level- a leveling instrument which uses a laser beam to check the relative ground elevation. laser levels are used by excavators and foundation contractors to ensure that the house is perfectly level. See transit.

lath and plaster- finishing system popular before the 1950's where thin strips of wood (lath) were attached horizontally to framed walls. Plaster was trowelled on top to provide a smooth durable finish surface for painting or wallpaper. The introduction of drywall panels made the labor intensive lath and plaster system obsolete.

lien- a legal right to sell another person property to satisfy a debt (see mechanics lien).

lintel- a horizontal structural supporting member that is used to support weight over an opening such as a door or window. Lintels made of angle iron are used to support brick or block over doors or windows.

live load- a load that is imposed on a building due to the use of the building. A person walking across a floor is an example of a live load.

load- the forces that are impose on a structure or structural member. For example, a ridge beam supports the load of the rafters and other materials that sit on top of it. It also supports the wind and snow loads.

lumber, dimensional- see dimensional lumber


manufactured housing- any house that is assembled off site and then transported to the building lot. Manufactured housing construction isn't required to follow the international building code.

masonry- construction composed of small units called bricks or blocks which are made from stone clay, concrete, tile and so forth. Units are held together by cement mortar mixture.

mastic- an adhesive use to attach ceramic tile to smooth wall surfaces.

mdf- medium density fiberboard; is a board made of wood fiber and glue. MDF is often used for moldings, casing, finish trim and cabinets. MDF will not split or crack easily.

miter joint- a joint made of by cutting two piece of material at equal angles, usually both are cut at 45° angle.

monolithic pour- a concrete pour where the concrete is cast in a single pour, thus it contains no joints. A monolithic pour is often used when pouring footings and foundations, thereby saving time and money.

mono truss- truss that has only one sloping angle. Often one end of the truss is set on an interior bearing wall and the tail end sets on an exterior wall.

molding- wood or mdf strip used for decorative purpose. Crown molding and chair rail are two common types of molding.


© Copyright 1999-2016 Construction Documents Co. All rights reserved.