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.
IAC2: The International Association of Certified Indoor Air Consultants.
IAQ: Acronym for indoor air quality.
ID (inside diameter): The diameter measurement taken from the inside of a pipe, and a common method for sizing pipe.
identify: To notice or observe and report upon.
IIC: In the United States, a system of criteria recommended by the Federal Housing Administration (FHA) for rating the effectiveness of impact sound isolation.
immediate cost: Estimated cost of remedying an existing safety hazard or repairing a system or component that will likely fail within a year.
imminent danger: A condition that could cause serious or life-threatening injury or death.
incandescent lamp: A lamp employing an electrically-charged metal filament that glows at white heat; a typical light bulb.
incompatibility: Descriptive of two or more materials that are not suitable for use together.
indemnification clause: A provision in a contract in which one party agrees to be financially responsible for specified types of damages, claims and/or losses.
index: The interest rate or adjustment standard that determines the changes in monthly payments for an adjustable-rate loan.
infestation: The presence of insects, vermin or other pests.
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.
infiltration: The process by which air leaks into a building. To find the infiltration heating load factor (HLF), the formula to account for the extra BTUs needed to heat the infiltrated air is BTU/HR = building volume x air changes x BTU/cu.ft./hr. x TD (temperature difference).
inlet: An opening that provides a means of entrance or intake.
INR (impact noise rating): A single-figure rating that provides an estimate of the impact sound-insulating performance of a floor-ceiling assembly.
inside corner: The point at which two walls form an internal angle, as in the corner of a room.
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.
inspect: To examine readily accessible areas, systems and components safely, using normal operating controls, according to applicable standards of practice.
inspected property: The readily accessible areas of the structure(s), site, items, components and systems included in an inspection.
inspection: The process by which an inspector collects information through visual observation during a walk-through survey of a subject property and then generates a meaningful report about the condition of the property based on his/her observations made on the date of the inspection. A general home inspection is a non-invasive, visual examination of the accessible areas of a residential property, as delineated by InterNACHI's Residential Standards of Practice, performed for a fee, which is designed to identify defects within specific systems and components defined by the Standards that are both observed and deemed material by the inspector. The scope of work may be modified by the client and inspector prior to the inspection process. A commercial inspection is defined as the process of an inspector collecting information through visual observation during a walk-through survey of the subject property, conducting research about the property, and then generating a meaningful report of his/her findings about the condition of the property based on his/her observations and research.
inspection report: A written report that identifies defects within specific systems and components, as defined by InterNACHI's Residential Standards of Practice, that are both observed and deemed material by the inspector. Inspection reports may include additional comments and recommendations. A commercial inspection report is defined as a written communication describing the issues discovered from observations made and research conducted by the inspector that are, in the inspector's opinion, likely to be of interest to his/her client. Such report may contain photos of observations made during the walk-through survey portion of the inspection and/or copies of documents reviewed during the research portion of the inspection.
inspector: One who performs a property inspection.
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.
insulating glass unit (IGU): Two or more lites of glass spaced apart with an air space between them and hermetically sealed to form a single glazed unit.
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.
interest: The cost paid to a lender for borrowed money.
interior finish: Material used to cover the interior framed areas, or materials of walls and ceilings.
interior glazed: Glazing infills set from the interior of the building.
interlayer: In glazing, any material used to bond two lites of glass and/or plastic together to form a laminate.
interlocking shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.
InterNACHI: The International Association of Certified Home Inspectors, the world's largest residential and commercial property inspectors' association, providing certification, training, benefits and support.
International Association of Certified Home Inspectors (InterNACHI): The world's largest residential and commercial property inspectors' association, providing certification, training, benefits and support.
International Energy Conservation Code (IECC): The IECC 2012 was published in June 2011.
interply: Between two layers of roofing felts that have been laminated together.
interview: To conduct research by talking to personnel who have information and knowledge about a subject property, typically performed as part of a commercial (as opposed to residential) property inspection.
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.
irrigation: A lawn sprinkler system.