Choose Steel Lintels by Load, Bearing and Wall Detail

Steel lintels support brickwork over doors, windows and other openings. Choosing one starts with what it carries and where that load goes, not simply the opening width. A loose angle supporting one leaf of brick veneer is a different assembly from a beam supporting a solid, load-bearing masonry wall.

For ordering and installation, the approved detail should establish the steel section, orientation, overall length, end bearing, finish and any connections or temporary support. These checks use U.S. brick-masonry guidance; the locally adopted code and project design govern.

Identify the support system first

Support type	Load path	Selection consequence
Loose steel angle	Spans the opening and bears on brickwork at both jambs; it is not attached to the building frame	Check the angle and the masonry supporting each end
Attached shelf angle	Transfers brickwork load through connections to the building structure	Design includes the angle, brackets or connections, and supporting structure
Multiple angles or beam-and-plate lintel	Supports the required thickness of solid masonry and applicable superimposed loads	A single veneer angle is not an interchangeable substitute

The Brick Industry Association’s April 2025 Technical Note 28B distinguishes loose lintels from shelf angles and states that they are not interchangeable. Its Technical Note 31B describes multiple-angle and beam-and-plate arrangements for solid masonry walls.

Do not assume the exterior lintel also supports the backing wall. The International Masonry Institute’s window-head detail shows a loose steel angle supporting brick veneer and a separate precast lintel supporting the CMU backing. Coordinate both supports; the broader concrete blockwork wall guide explains the CMU assembly. Under 2021 IRC Section R703.8.3, masonry veneer must not carry vertical loads other than the dead load of the veneer above.

What determines the steel section?

Give the designer or lintel supplier more than a clear-span measurement:

• Wall construction: veneer or load-bearing masonry, actual brick thickness, number of leaves and bond pattern.
• Opening geometry: clear width, brickwork height above, nearby openings and available jamb widths.
• Loads: masonry weight and, where applicable, floor, roof, beam or truss loads reaching the support.
• Support condition: loose bearing, frame attachment, lateral restraint and load eccentricity.
• Exposure and assembly requirements: corrosion protection, drainage, movement and any required fire protection.

The design must check strength and stiffness. An angle can remain below its strength limit yet deflect enough to crack the brickwork. Loading away from the angle’s shear center can also cause twisting, so bending capacity alone may not settle the choice. BIA Technical Note 31B addresses these separate checks.

For brick veneer over cold-formed steel framing, BIA’s 2025 guidance limits loose-lintel and shelf-angle deflection between support points to L/600—one six-hundredth of that span. The designer must establish the applicable span, loading and serviceability limits for the project, including rotation where applicable.

A span table is usable only when its assumptions match. In particular, BIA’s older 31B angle table assumes lateral support and calls for reduced allowable loads for unsupported angles and special investigation where torsion occurs. Do not apply that table unchanged to an unrestrained loose angle.

Bearing controls length—not just fit

End bearing transfers the lintel reactions into the jamb masonry. Both the contact area and the supporting masonry must be adequate; narrow piers between adjacent openings may receive reactions from more than one lintel. BIA’s bearing discussion makes those checks part of the design.

For a specific U.S. residential reference, 2021 IRC Section R703.8.3 requires at least 4 inches (102 mm) of lintel bearing for masonry veneer. BIA’s April 2025 steel-framed veneer guidance likewise specifies 4 inches minimum on brick at each side. A minimum is not proof that the bearing is sufficient for every load.

For example, a 6-foot clear opening with specified 4-inch bearing at each end needs an 80-inch overall lintel length:

72 in. + 4 in. + 4 in. = 80 in.

That arithmetic establishes length only—not angle size, capacity or the suitability of the jambs.

Detail water, corrosion and movement together

Corrosion protection does not replace flashing. Water penetrating the veneer needs a continuous route back outside, rather than collecting at the opening head.

Check that the detail provides:

• Through-wall flashing over the lintel, connected to the backing’s water-control system.
• Turned-up flashing ends forming end dams.
• An exterior discharge edge or drip as detailed.
• Weeps immediately above the flashing, with the drainage path clear of mortar droppings.

The IMI window-head detail illustrates lintel flashing, end dams, a drip edge and protection against blocked weeps. BIA’s 2025 guidance calls for integration with the water-resistive barrier and specifically warns that weeps one or two courses above flashing will not perform their intended function.

Use the specified steel and protective finish. BIA recommends priming and coating carbon-steel angles, with hot-dip galvanized or stainless-steel angles considered for harsher exposure such as coastal conditions. Confirm the finish before ordering, when concealed surfaces are still accessible.

Movement details also depend on the support type. In multistory walls where the lintel continues a shelf angle supporting masonry panels, provide a horizontal movement joint beneath it. Vertical expansion joints meeting lintel ends require coordinated detailing—not a mortar-filled interruption of the joint. BIA Technical Note 31B addresses both conditions.

Check before laying above the opening

Before concealing the steel, verify the delivered section and orientation against the approved drawing, measure bearing at both ends, and inspect the finish, flashing, end dams, weeps and movement joints. For attached supports, also verify the specified connections and bracing.

Finally, confirm the construction-stage support plan. Do not assume fresh brickwork already provides arching action. BIA explains that a lintel designed to rely on masonry arching needs temporary shoring until the masonry has developed sufficient strength. Whether arching is credited—and when supports can be removed—must follow the project design and construction conditions, not a crew’s assumption based on the finished wall. BIA Technical Note 31B