Lintels (headers) are the horizontal framing members that span over an opening such as a window or door to carry loads to the adjoining studs. Lintels are usually constructed of two pieces of timber separated with spacers to the width of the studs and nailed together to form a single unit. The preferable spacer material is rigid insulation. The depth of a lintel is determined by the width of the opening and vertical loads supported. Lintels are bending members that attract floor or roof loads from above and carry them to either side of the opening. Often extra studs are needed on either side of the opening to carry the larger vertical forces to the bottom of the wall frame.