Steel lintels and shelf angles

What it is

A steel lintel carries the masonry above a window, door or service opening and transfers the load to the wall on either side. The simplest is a loose angle lintel: one or two hot-rolled angles that sit in the wall with bearing at each end. Wider or heavier openings use back-to-back angles, a plate welded to a beam flange, or a built-up section that supports both leaves of a cavity wall. Shelf angles are related items: continuous angles bolted to the building frame or slab edge that support brick veneer at each floor and allow for movement.

World Steel supplies lintels and shelf angles as part of misc. metals packages for buildings with masonry walls, often together with embed plates and the steel frame itself. Interfaces between steel, masonry and precast are described in masonry and precast interfaces.

Types and options

Options include pre-cut lengths with end bearing allowances, holes for wall ties or fixings, welded end stops, horizontal and vertical slots for adjustment on shelf angles, and stainless steel for high-durability façades.

Design and compliance

Lintels are sized by the designer for the opening width, the masonry load above (allowing for arching where the code permits), any floor or roof loads, and deflection limits that protect the masonry from cracking. In the US, masonry lintels are designed to TMS 402/602 with steel members to AISC 360. In Australia, AS 4100 governs the steel design, AS 3700 the masonry, and AS/NZS 2699.3 sets the durability (coating) requirements for lintels and shelf angles according to exposure. In Europe, lintels for masonry are covered by the harmonised standard EN 845-2, so lintels placed on the EU market carry CE marking; steel design follows EN 1993-1-1.

Corrosion is the main long-term risk, because lintels are hidden inside the wall and are hard to inspect or replace. That is why galvanizing, or galvanizing plus paint, is the normal specification for external walls.

Fabrication and finishing at World Steel

Angles, channels and plates are cut and drilled on CNC lines to the opening schedule; built-up lintels are welded by qualified welders to AWS D1.1, AS/NZS 1554.1 or EN ISO 3834-2 procedures. Each lintel is marked with its opening reference so site crews can place it without measuring. After shot blasting, lintels are hot-dip galvanized by qualified galvanizers to ASTM A123 / AS/NZS 4680 / EN ISO 1461; a paint topcoat can be added as a duplex system in severe exposures. See paint and coating systems and surface preparation.

Installation and site notes

• Lintels are bedded level on mortar with the end bearing shown on the drawings; the vertical leg faces up.
• Flashing or a damp-proof course is placed over the lintel to drain water out of the cavity.
• Shelf angles are bolted to cast-in channels, embeds or the steel frame and shimmed to line and level, leaving the movement joint below.
• Damaged galvanizing from handling or site cutting is repaired to ASTM A780 or the regional equivalent.

Selecting and specifying

Send an opening schedule listing each opening width, wall type and thickness, the lintel section (or loads if World Steel is to propose sizes for approval), bearing length, finish and quantity. For shelf angles, include the slab edge or frame details, the fixing type and the brick module. Lintels and shelf angles fit naturally into a combined package with canopies, bollards and other building accessories.