H-clip: A small metal clip in the shape of the letter H that fits at the joint of two plywood or waferboard sheets used to stiffen the joint at roof sheeting.

 

habitable space: The space in a structure used for living, sleeping, eating and cooking. Bathrooms, closets, hallways, storage areas and utility rooms are not considered habitable spaces.

 

hardware: Metal accessories, such as hinges, door knobs, drawer pulls, towel bars, toilet paper holders, etc.

 

hatch: An opening in a deck, floor or roof whose purpose is to provide access from inside the home or building.

 

haunch: A knee-like protrusion or extension of a foundation wall upon which a concrete porch or patio rests for support.

 

header: The framing members over windows, doors and other openings. A beam placed perpendicular to joists and to which joists are nailed in framing for a chimney, stairway, or other opening.

 

hearth: The inner and outer floor of a fireplace, usually made of brick, tile or stone.

 

hearth extension: The non-combustible material in front of and at the sides of a fireplace opening.

 

heat pump: A device that uses compression and decompression of gas to heat and/or cool a house.

 

heat rough: The work performed by the heating or HVAC contractor after the stairs and interior walls are built, and includes installing all ductwork and flue pipes. The furnace and fireplace are sometimes installed at this stage of construction.

 

heat trim: The work performed by the heating or HVAC contractor to prepare a new-construction home for the final municipal heat inspection. This work includes venting the hot water heater and range, and installing all vent grilles, registers, thermostats, vent hoods, air-conditioning services, turning on the furnace, and all other heat-related work.

 

heat-strengthened glass: Flat or bent glass that has been heat-treated to a specific surface and/or edge-compression range to meet the requirements of ASTM C 1048, Type HS. Heat-strengthened glass is approximately two times as strong as annealed glass of the same thickness when exposed to uniform static pressure loads. Heat-strengthened glass is not considered safety glass and will not completely dice in the manner that fully tempered glass will.

 

heated slab: Slab-on-grade construction in which the heating elements are placed within or under the slab.

 

heating load: The amount of heating required to keep a home or building at a specified temperature during the winter (usually, 65° F), regardless of the outside temperature.

 

heating seasonal-performance factor (HSPF): A measure of a heat pump's energy efficiency over one heating season, representing the total heating output of a heat pump (including supplementary electric heat) during the normal heating season (in BTUs), as compared to the total electricity consumed (in watt-hours) during the same period. HSPF is based on tests performed in accordance with AHRI 210/240 (AHRI 2003).

 

heel cut: A notch cut into the end of a rafter that permits it to fit flat on a wall and on the top doubled exterior wall plate.

 

hermetic seal: A vacuum seal between the panes of a double-paned window or insulated glass unit (IGU). A hermetic seal that fails causes permanent fogging between the panels of the IGU.

 

hip: The external angle formed by the meeting of two sloping sides of a roof.

 

hip rafter: A rafter that forms the intersection of an external angle at a roof.

 

hip roof: A roof that rises by inclined planes from all four sides of the building.

 

hip shingles: Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.

 

home run (electrical): The electrical cable that carries power from the main circuit breaker panel or panelboard to the first electrical box, plug or switch in the circuit.

 

hood: A device installed over a range or cooktop that directs and captures grease-laden vapors and gases into an exhaust system, which then are vented to the exterior.

 

hose bib: An outdoor faucet with hose threads on its spout for the attachment of a garden hose, lawn sprinkler device, etc. Also installed at the interior for the attachment of a washing machine, wash basin, utility sink, etc.

 

hot wire: The typically black wire that carries electrical energy to a receptacle or other device?in contrast to a neutral, which carries electricity away again.

 

hub: In plumbing, the enlarged end of a pipe that is made to provide a connection into which the end of a joining pipe will fit.

 

humidifier: A device designed to increase the humidity within a room or a house by means of the discharge of water vapor. It may consist of an individual room-size unit or a larger unit connected to the heating plant to condition the entire house.

 

humidistat: A device used to automatically control relative humidity indoors.

 

HVAC: Acronym for heating, ventilation and air conditioning; refers to the system, work, and type of contractor.

 

I

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I-beam: A steel beam with a cross-section resembling the letter I, it is used in residential construction for long spans, such as a basement beam, and when wall and roof loads are imposed on an opening, such as over wide wall openings and double garage doors.

 

I-joist: A manufactured structural building component resembling the letter I, it is used as a floor joist and rafter. I-joists include two key parts: flanges and webs. The flange of the I joist may be made of laminated veneer lumber or dimensional lumber, usually formed into a width of 1-1/2 inches. The web or center of the I-joist is commonly made of plywood or oriented strand board (OSB). Large holes can be cut in the web to accommodate ductwork and plumbing waste lines. I-joists are available in lengths of up to 60 feet long.

 

incandescent lamp: A lamp employing an electrically-charged metal filament that glows at white heat; a typical light bulb.

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infill: The area of a railing system bounded by the railing posts, cap, rail and deck or floor surface. For safety reasons, typical infill spacing (U.S.) should prevent the passage of a 4-inch sphere.

 

inside drain: In roofing, a drain positioned on a roof at some location other than the perimeter. It drains surface water inside the building through closed pipes to a drainage system.

 

installed: Attached or connected such that the installed item requires a tool for removal.

 

insulating glass: Window or door in which two panes or lites of glass are used with a sealed air space between; also known as double glass.

 

insulation: Generally, any material that slows down or retards the flow or transfer of heat. Building insulation types are classified according to form as loose-fill, flexible, rigid, reflective, and foamed-in-place. All types are rated according to their ability to resist heat flow, known as R-value. In electrical contracting, rubber, thermoplastic, or asbestos wire covering. The thickness of insulation varies with wire size and type of material, application or other code limitations.

 

insulation board: A rigid structural building board made of coarse wood or cane fiber in 1/2-inch and 25/32-inch thickness. It can be obtained in various sizes of sheets, in various densities, and with several treatments.

 

insulation fasteners: Any of several specialized mechanical fasteners designed to hold insulation down to a steel or a nailable deck.

 

interior finish: Material used to cover the interior framed areas, or materials of walls and ceilings.

 

interlocking shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.

 

interply: Between two layers of roofing felts that have been laminated together.

 

IPS (iron pipe size): A pipe thread sizing system; also, a measurement of the outside diameter of a pipe.

 

IRMA (insulated/inverted roof membrane assembly): A roof system whose membrane is laid directly on the roof deck, covered with extruded foam insulation, and ballasted with stone at a minimum of 1,000 pounds per square.

 

J

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J-channel: Metal edging used on drywall to give the edge a better finished appearance when the wall is not wrapped. Generally, basement stairway walls have drywall only on the stair side. J-channel is used on the vertical edge of the last drywall sheet.

 

jack post: A type of metal structural support used as a replacement for an old/defective supporting member that can be raised or lowered through a series of pins and a screw to meet the height required. See also monopost.

 

jack rafter: A rafter that spans the distance from the wall plate to a hip, or from a valley to a ridge.

 

jalousie window: A type of window consisting of parallel glass, acrylic, or wooden louvers set in a frame, which are locked together onto a track and controlled by a crank mechanism so that they may be tilted open and shut in unison to control air flow through the window. Jalousie windows are popular in hot-humid climates.

 

jamb: The side and head lining of a doorway, window or other opening.

 

joint: The space between the adjacent surfaces of two members or components joined and held together by nails, glue, cement, mortar, or other means.

 

joint cement: A powder that is usually mixed with water and used for joint treatment in gypsum-wallboard finish. Also called spackle.

 

joint compound: In plumbing, a material applied to threaded connections to help prevent leaks in plumbing. In carpentry, a wet gypsum material applied to sheetrock joints.

 

joist hanger: A metal U-shaped item used to support the end of a floor joist and attached with hardened nails to another bearing joist or beam.

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K

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Keene's cement: A white finish plaster that produces an extremely durable wall. Because of its density, it excels for use in bathrooms and kitchens, and is also used extensively for the finish coat in auditoriums, public buildings, and other places where walls may be subjected to unusually hard wear or abuse.

 

keeper: The metal latch plate in a door frame into which a doorknob plunger latches.

 

keyless: A plastic or porcelain light fixture that operates by a pull string, typically found in a basement, crawlspace and attic.

 

keyway: A slot formed and poured on a footer or in a foundation wall when another wall will be installed at the slot location, giving additional strength to the joint/meeting point.

 

kick hole: A defect frequently found in perimeter flashings caused by being stepped on or kicked; a small fracture of the base flashing in the area of the cant.

 

kickout flashing: Also known as diverter flashing, kickout flashing is a special type of flashing that diverts rainwater away from the cladding and into the gutter. If missing, it often results in concentrated areas of water accumulation and potentially severe damage to exterior walls.

 

kiln-dried lumber: Lumber that has been kiln-dried to a moisture content of 6 to 12%. Common varieties of softwood lumber, such as framing lumber, are dried to a slightly higher moisture content.

 

kilowatt (kw, KW): One kilowatt is equal to 1,000 watts. A kilowatt hour is the base unit used in measuring electrical consumption.

 

king stud: The vertical 2x4 frame lumber (left and right) of a window or door opening running continuously from the bottom sole plate to the top plate.

 

kraft paper: A low-cost, heavy, water-resistant paper of high tensile strength used for wrapping particleboard and other building materials.

 

Kynar coating: A resin-based architectural coating that is UV-stable and suitable for exterior use on aluminum and other metal surfaces.

 

L

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laminate: Any laminated product, such as plywood.

 

laminated glass: Two or more lites of glass permanently bonded together with one or more inter-layers.

 

laminated shingles: Shingles that have added dimensionality because of extra layers or tabs, giving them a shake-like appearance. Also called architectural shingles and three-dimensional shingles.

 

laminating: Bonding together two or more layers of materials.

 

landing: A platform between flights of stairs or at the termination of a flight of stairs.

 

lap: To extend one material partially over another; also, the distance so extended.

 

lap cement: An asphalt-based cement used to adhere overlapping plies of roll roofing.

 

lateral: The underground trench and related services or utilities (electric, gas, telephone, sewer and water lines) that are buried within the trench.

 

lath: A building material of wood, metal, gypsum or insulating board that is fastened to the frame of a building that acts as a plaster base.

 

lath and plaster: The most common wall finish prior to the introduction of drywall. Thin wood strips (lath) were nailed onto the framing as a base for the sand/lime plaster.

 

lavatory: Bathroom or washroom sink.

 

leach field: A septic drainfield; a method by which sewage is permitted to be filtered and discharged into the ground near a home, typical in rural areas not accessible to a municipal sewer system.

 

lead: A malleable metal once extensively used for flashings.

 

lead-based paint: Lead is a highly toxic heavy metal that was used in exterior and interior household paint before it was outlawed in the U.S. in 1978. Exposure or ingestion to disturbed lead-based paint can cause a range of short- and long-term health problems, from behavioral issues and learning disabilities, to seizures and death. Children under 7 are at greatest risk.

 

leader: Downspout.

 

lean-to roof: The sloping roof of a building addition having its rafters or supports pitched against and supported by the adjoining wall of a building.

 

ledger: Dimensional lumber attached to a building framing and used for supporting the section of a deck adjacent to the building.

 

ledger strip: A strip of lumber nailed along the bottom of the side of a girder on which joists rest.

 

limit switch: A safety control that automatically shuts off a furnace if it gets too hot; must also control blower cycles.

 

lintel: A horizontal structural member that supports the load over an opening, such as a door or window.

 

liquid-applied membrane: Generally applied to cast-in-place concrete surfaces in one or more coats to provide fully-adhered, waterproof membranes that conform to all contours.

 

listed: Equipment, materials or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with the evaluation of products or services that maintains periodic inspection of the production of listed equipment or materials, or periodic evaluation of services, and whose listing states that the equipment, material or service meets appropriate designated standards, or has been tested and found suitable for a specified purpose.

 

lite: A pane of window glass (variation of light).

 

live load: Loads produced by use and occupancy of a building or other structure, not including construction or environmental loads, such as wind load, snow load, ice load, rain load, seismic load, or dead load.

 

load-bearing wall: A wall that supports its own weight and some other structural elements of a house or building, such as the roof and ceiling structures.

 

lookout: A short wooden bracket or cantilever, usually concealed from view, that supports an overhanging portion of a roof or similar structure.

 

loose-laid: In roofing, a membrane laid loosely and not adhered over a roof deck or berm.

 

lot: A parcel of ground with boundaries determined by the county.

 

louver: A horizontal slat. A louvered window is constructed of a series of horizontal slats in a window space arranged so as to permit ventilation but prevent the entry rain or sunlight. Louvers are also used in attic ventilators, which are mechanical fans that move large amounts of air at a low velocity.

 

low-slope application: A method of installing asphalt shingles on roof slopes between 2 and 4 inches per foot.