A lintel is a structural beam placed above a window and door to support the weight of the wall above. A lintel may be composed of reinforced brick masonry, precast concrete, or most commonly, as in the Case Study above, structural steel. The primary function of the lintel is to transfer the load originating from the upper wall to the side wall of the building.
Lintels are typically situated on top of the last brick course that is level or approximately level with the top of the window or door frame. The bricks above the wall opening on which the lintels rest can be strengthened by the installation of steel reinforcing bars.
Structural Design
To eliminate the possibility of structural cracks in the wall above these openings, the structural design of the lintel should be determined by careful analysis of the load to be carried and calculation of the stresses that need to be handled. If these factors are not taken into account, problems of cracking and spalling could occur.
Moisture Control
Consideration must also be given to moisture control wherever there are openings in masonry walls. There must always be a mechanism to channel the flow of water to the outside. Flashing should be installed on the lintel to allow any water that might enter the masonry to filter out over the lintel. Some of the most common leaks occur over the windows because of improper flashing details.
Types of Steel Lintels
There are several different types of structural steel lintels used in masonry. They vary from single angle lintels in cavity or veneer walls, to steel beams with plates in solid walls, to shelf angles in brick veneer panel walls.
Installation
Installation of steel lintels in masonry walls is a conventional construction operation. The walls are built to the height of the opening, the lintel is installed over the opening, and the masonry work is continued.
