I-beam - Are beams with an I- or H-shaped cross-section. The horizontal elements are flanges, while the vertical element is the web In Canada, steel I-Beams are now commonly specified using the depth and weight of the beam in metric terms. For example, a "W250x33" beam is approximately 250 mm in depth (height when the I-Beam is standing on its flanges) and weighs approximately 33 kg/m (kilograms per linear metre)

Icynene® - Icynene® is a soft foam insulation and air barrier system.

I.D. - Abbreviation for Inside Diameter.

Ice Damming - Condition that occurs when snow melts on the heated portion of an improperly ventilated roof. The water drips down to the unheated portion where it freezes into ice. Eventually the build up of ice will cause the roof to leak.

I-joist - Manufactured structural building component resembling the letter "I". Used as floor joists and rafters. 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 1 ½" width. 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 duct work and plumbing waste lines. I-joists are available in lengths up to 60 feet long.

Inactive Door - The door of a pair, which is secondary in usage and is normally locked by surface or flush bolts.

Incandescent Lamp - A lamp employing an electrically charged metal filament that glows at white heat. A typical light bulb.

Index - The interest rate or adjustment standard that determines the changes in monthly payments for an adjustable rate loan.

Infiltration - The passage of air from indoors to outdoors and vice versa; term is usually associated with drafts from cracks, seams or holes in buildings.

Inside Corner - The point at which two walls form an internal angle, as in the corner of a room.

Inspections - During construction, several mandatory inspections are required to ensure that all work is done according to the reviewed drawings and the OBC. The following are inspections that may be required during the course of construction for new residential buildings and additions:

• o Footings: Prior to pouring concrete footings.
• o Foundation Pre-backfill: Upon completion of the foundation and prior to backfilling.
• o Framing: Completion of total framing, including electrical work, plumbing, central vacuum and heating rough-in.
• o Electrical Rough-in - Ontario Electrical Safety Authority (E.S.A.)
• o Insulation, Air and Vapour Barrier: Completion of insulation, air and vapour barriers, prior to applying the interior finishes.
• o Fire Separations: The framing for the walls, floors and shaft fire separations, closures and fire stopping are completed, prior to applying the interior finishes.
• o Plumbing Outside Services: Installation of building drains and water supply to building.
• o Plumbing Inside Services: Installation of drains and water supply under the basement floor.
• o Plumbing Rough-in: Prior to installing insulation.
• o Plumbing Final: Installation of hot water tank and all required plumbing fixtures, prior to occupancy.
• o HVAC Rough-in: Prior to installing insulation.
• o Final HVAC: Installation of furnace and all required systems and grilles, prior to occupancy.
• o Electrical Final: Ontario Electrical Safety Authority (E.S.A.)
• o Final Interior: Completion of finishes, handrails, guards, smoke alarms and gas proofing, prior to occupancy.
• o Final Exterior: Completions of all exterior work including site grading, caulking, balconies, landings, and finish materials.

Insulating Glass - Window or door in which two panes of glass are used with a sealed air space between. Also known as Double glass.

Insulation Board, Rigid - A structural building board made of coarse wood or cane fiber in ½- and 25/32-inch thickness. It can be obtained in various size sheets and densities.

Insulation - Any material high in resistance to heat transmission that, when placed in the walls, ceiling, or floors of a structure, and will reduce the rate of heat flow.

Interest - The cost paid to a lender for borrowed money.

Interior Finish - Material used to cover the interior framed areas of walls and ceilings.

Inverted Dormer - the term inverted means that the dormer windows, rather than projecting forward from the roof plane, are set behind in a short recess.

Irrigation - Lawn sprinkler system.