Lintel

A lintel is a horizontal structural member placed across the top of a door or window opening in a masonry or concrete wall. It transfers the weight of the masonry above the opening to the wall sections on each side. Without a lintel, the masonry above the opening has no support and the opening would collapse under its own weight.

In wood-frame construction, the equivalent element is called a header. In block, brick, or poured concrete construction, it is a lintel. The distinction matters to garage door installers because the material of the lintel determines what can be anchored into it and how.

Common lintel types in residential and commercial garages:

• Steel angle lintel - A single or paired L-shaped steel angle iron spanning the opening. Common in residential brick-veneer construction where the brick skin has its own lintel separate from the structural header inside the wood frame.
• Precast concrete lintel - A reinforced concrete beam cast off-site and set in place. Common in concrete block (CMU) construction.
• Cast-in-place concrete lintel - Poured as part of a concrete block course with rebar inside. Forms a monolithic bond beam across the opening.
• Steel tube or wide-flange beam - Used in heavy commercial masonry construction for wide openings or heavy loads.

For garage door installation, the lintel determines where the torsion spring center bracket can anchor. A steel angle lintel can accept self-drilling screws or bolts through the web. A concrete lintel requires expansion anchors or sleeve anchors. An undersized lintel that deflects under load will shift the spring assembly, causing the door to bind or the bracket to pull out over time.

The vertical distance from the top of the door opening to the bottom of the lintel (or the underside of any structural element directly above) is the key measurement for headroom calculations. Rolling steel doors used in masonry openings often list a required lintel clearance in the manufacturer's installation specification.