Steel and concrete lintels both span openings and carry the masonry or wall above; the right one mostly depends on the wall. Over windows and doors in brick veneer, the standard in Ontario is a steel angle lintel: thin enough to hide in a mortar joint, light enough for one person to set, and sized straight from the Ontario Building Code tables. In concrete block, ICF and poured concrete walls, a reinforced concrete lintel (precast, cast in place or a grouted bond beam) often fits better because it matches the wall and doesn't rust. Wide or heavily loaded openings in any wall may need a steel beam instead of either.
What the Ontario Building Code allows
The 2024 Ontario Building Code (O. Reg. 163/24), Sentence 9.20.5.2.(1), says masonry over openings is supported by steel lintels, reinforced concrete lintels or masonry arches designed to support the imposed loads. All three are acceptable. The difference is how much is spelled out:
- Steel angle lintels have prescriptive tables. Table 9.20.5.2.-A covers loose steel angle lintels in masonry walls, including floor loads, and Table 9.20.5.2.-B gives maximum spans for angles supporting masonry veneer. Steel lintels need at least 150 mm of even, level bearing at each end on masonry, concrete or steel, and angle lintels supporting masonry must be prime painted or otherwise protected from corrosion.
- Reinforced concrete lintels in ordinary masonry walls have no prescriptive table in Part 9; they are designed, or come as precast units whose maker provides capacity data.
- ICF walls are the exception. In loadbearing flat ICF walls, Article 9.20.17.4 requires lintels over openings wider than 900 mm, built to Span Tables 9.20.17.4.-A to -C (which use 10M or 15M bottom bars), with 10M stirrups for shear over openings wider than 1,200 mm.
For the steel tables in detail, see our guide to steel lintel sizes under the Ontario Building Code.
Steel lintel vs concrete lintel side by side
| Steel angle lintel | Concrete lintel | |
|---|---|---|
| Typical forms | Single angle under veneer; double angles in block or solid masonry | Precast unit, cast-in-place beam, grouted bond beam, ICF lintel |
| Depth at the opening | Only the angle leg, hidden in the coursing | A full block course or more |
| Weight | Light; usually set by hand | Heavy; precast units may need two people or equipment |
| Sizing | OBC tables for common cases | Designed, maker's data or ICF tables |
| Long spans | Deeper angles, then a steel beam | Deeper section and more bars |
| Corrosion | Rusts if kept wet; needs primer or galvanizing and good flashing | Doesn't rust itself, but its rebar can corrode if cover is thin or cracked |
| Fit with brick veneer | Excellent | Rare in veneer walls |
| Fit with block, ICF, poured walls | Workable, sometimes awkward | Natural fit |
| Retrofit into an existing wall | Easy to slide in after cutting the opening | Harder; precast must be lifted in, cast-in-place needs forming |
| Lead time | Cut from stock or fabricated to order | Precast from stock sizes; cast-in-place needs curing time |
Where steel lintels win
Brick and stone veneer on wood-frame houses. This is most of Ontario's housing stock. The veneer is a single wythe in front of a stud wall, and the angle sits in a mortar joint at the head of the opening with its vertical leg tucked behind the brick. A concrete lintel would show a full course of concrete in the brick face and add a lot of weight. The structural load above the opening is carried by the wood header in the stud wall, not the angle.
Retrofits and new openings. Cutting a new window or widening a door in an existing masonry wall is far easier with steel, because angles can be slid into a slot and shimmed to bear. Our post on installing a steel lintel in an existing brick wall explains the process and who does what.
Thin profiles and long, shallow openings. Where the head of an opening has to stay slim, a steel angle, or a steel beam with a bottom plate for heavier loads, keeps the depth down.
Where concrete lintels win
Concrete block walls. Precast concrete lintels and grouted bond beam lintels are sized to the block coursing, so they lay up like the rest of the wall and carry the full wall thickness. Reinforced block construction usually uses bond beams with bars and grout. Our guide to steel lintels in concrete block walls compares steel and masonry options for block.
ICF and poured concrete walls. The lintel is simply a reinforced section of the wall over the opening, formed and poured with everything else. The OBC's ICF lintel tables cover common cases, and engineered walls are detailed on the drawings. No separate lintel is needed.
Wet or exposed locations. A properly made concrete lintel doesn't rust the way an unprotected angle can. That said, the rebar inside it still needs enough concrete cover, and a cracked precast unit can let water reach its bars.
Durability: rust vs cracking
The most common lintel failure in older Ontario houses is a rusted steel angle. Steel expands as it rusts, which lifts the brick above and cracks the mortar in a stair-step pattern at the corners of the opening. It's almost always caused by water: missing or failed flashing, blocked weep holes, or a coating that wore through. A primed angle behind well-flashed masonry can last many decades, and galvanizing adds protection where the detail is likely to get wet. See do steel lintels rust? for prevention.
Concrete lintels fail differently. If their bars corrode, the expanding rust spalls the concrete off the underside. They can also crack from overload or poor bearing. Either way, both materials last when water is kept away from them, and both need proper bearing at the ends.
What drives the cost of each
We don't publish prices, but the cost drivers are predictable:
- Steel lintels: angle size and length, whether it's a single angle, a bolted pair or a beam with a welded plate, priming or galvanizing, and quantity. Installation into new masonry is quick; retrofits add cutting, shoring and masonry repair.
- Precast concrete lintels: unit size and length, handling weight, and delivery. Standard sizes from stock are straightforward; custom lengths or loads add design.
- Cast-in-place and bond beam lintels: forming, rebar, grout or concrete, and time to cure before loading.
- Either one: engineering for anything outside the tables, and the masonry work around it, which is often the biggest line.
For steel specifically, our post on what drives steel lintel cost in Ontario goes through the factors.
Which one should you use?
- Brick or stone veneer on a wood-frame house: steel angle lintel from the OBC veneer table.
- Solid masonry walls carrying floors: steel angles from Table 9.20.5.2.-A, or a designed lintel.
- Concrete block walls: precast concrete, bond beam or double steel angles, as the designer prefers for the span and load.
- ICF and poured walls: a reinforced concrete lintel as part of the wall.
- Wide or heavily loaded openings in any wall: a designed steel beam or reinforced concrete beam.
- Replacing a failed lintel: match the load and wall, and get the design confirmed before anything is removed.
Any new or widened opening in a loadbearing wall needs a designer or engineer and usually a building permit.
Getting your lintels made
We fabricate steel angle lintels cut to length, double angles bolted to suit, and steel beams with welded bottom plates, and we can prime or galvanize them. If your opening calls for a concrete lintel, we also detail, cut and bend the rebar for cast-in-place and ICF lintels, including stirrups. Send us your drawings or opening sizes, or see our steel products.
Frequently asked questions
Is a steel lintel better than a concrete lintel?
Neither is better everywhere. Steel angle lintels are thin, light and the standard choice over openings in brick veneer. Concrete lintels suit block, ICF and poured concrete walls, where they match the wall and don't rust. The wall type usually decides.
What does the Ontario Building Code allow over openings in masonry?
Sentence 9.20.5.2.(1) of the 2024 OBC allows steel lintels, reinforced concrete lintels or masonry arches designed to support the loads. Steel angle lintels can be picked from Tables 9.20.5.2.-A and -B, with at least 150 mm of bearing at each end and a prime coat or other corrosion protection.
Do concrete lintels need rebar?
Yes. Concrete is weak in tension, and the bottom of a lintel is in tension, so a concrete lintel needs bottom reinforcing bars. Precast lintels have the steel cast in at the plant; cast-in-place and ICF lintels get bars placed on site.
Can a steel lintel replace a concrete lintel?
Sometimes, but it is a design decision. A replacement has to carry the same loads, fit the wall thickness and have proper bearing. Wide or loaded openings may need a steel beam with a bottom plate rather than angles, sized by a designer or engineer.
