I-Beam – Steel beam with a cross-section that resembles a capital I. Used as a main structural support over large openings such as garage doors, or in basements where a long span is needed without the aggravation of numerous pillars.

Insulation – Any medium that stops the transfer of heat or cool from one area to another.

Interior Finish – Covering used on interior walls or ceilings, stipple or other finish used on ceilings, wallpaper, paneling, and paint.

Interior Trim – Any interior woodwork designed to conceal unfinished edges or joins. Woodwork used to decorate around doors and windows, baseboard, moldings etc.

Joist – A beam that typically supports a floor. Typically a 2″x10″.

Joist Hangar – A steel piece that can be nailed to the side of one joist and holds the end of a joist that needs to be secured to it at a 90-degree angle.