A steel angle lintel sized from the Ontario Building Code needs at least 150 mm of bearing at each end, and the bearing must be even, level and on masonry, concrete or steel. That rule is Sentence 9.20.5.2.(3.1) of the 2024 Ontario Building Code, and it means every lintel is at least 300 mm longer than the opening it spans. Engineered lintels can need more.
Bearing is the part of a lintel job that is easy to get wrong in the field: a short lintel, a bearing that lands on a hollow block face or a window frame, or an end that's packed up on loose shims. Here is what the code requires and what to check.
The 150 mm rule in the 2024 OBC
Article 9.20.5.2. of the 2024 OBC (O. Reg. 163/24, Division B) covers lintels over openings in masonry. Sentence (3.1) says that steel lintels sized from Table 9.20.5.2.-A (solid masonry walls) and Table 9.20.5.2.-B (masonry veneer) shall:
- have even and level bearing,
- have not less than 150 mm length of bearing at end supports, and
- bear on masonry, concrete or steel.
Ontario replaces the national code's lintel article with its own, so national code tables and US or UK guidance on bearing lengths don't apply directly here. For the span tables themselves and how to choose an angle size, see our guide to steel lintel sizes under the Ontario Building Code.
Lintel bearing compared with beam bearing
People sometimes assume a lintel needs the same bearing as a floor beam. It doesn't: the code asks for more.
| Member | Minimum end bearing in Part 9 | Clause |
|---|---|---|
| Steel angle lintel from Table 9.20.5.2.-A or -B | 150 mm, even and level, on masonry, concrete or steel | 9.20.5.2.(3.1) |
| Beam supported on masonry | 90 mm, with enough bearing area for the load | 9.20.8.3. |
| Beam supporting floors (general) | 89 mm, even and level | 9.23.8.1. |
| Steel beam carrying veneer and a stud wall (Table 9.20.5.2.-C) | Supported at each end by a steel column | 9.20.5.2.(6) |
Source: 2024 Ontario Building Code, Division B. Beam bearing on concrete and masonry is covered in detail in our post on steel beam bearing length.
The difference makes sense: an angle lintel is a light member sitting in a masonry joint, and a longer bearing spreads its end load into the brick below and keeps the end from rotating as it deflects.
What a steel lintel can bear on
The code lists three acceptable supports: masonry, concrete or steel. In practice that means:
- Brick or stone piers at each side of the opening in a veneer or solid masonry wall. The bearing has to reach sound masonry, not a cut half-brick or loose units.
- Concrete, such as a foundation wall or a poured bearing block.
- Steel, such as a post, a plate or another member.
What it does not include: wood framing, the window or door frame, or a stack of shims. A veneer lintel sits in the brick, not on the wood wall behind it. And on a renovation where the opening is widened right up to a corner or another opening, there may not be enough masonry left to provide 150 mm of sound bearing, which is a design problem to solve before the brick comes out.
"Even and level" is a real requirement. The lintel is bedded in mortar and levelled so it bears along its full bearing length, not on one high point at the end of the brick.
Do steel lintels need padstones?
"Padstone" is a UK term for a solid concrete or stone block placed under the end of a lintel or beam to spread the load. The Ontario code doesn't use the word. For lintels sized from the OBC tables, the requirement is simply even, level bearing at least 150 mm long on masonry, concrete or steel.
A designer may still call for a solid bearing under a lintel end when:
- the lintel bears on hollow concrete block, where the load should go into solid units or filled cores rather than thin face shells,
- a beam, post or girder truss lands on or near the lintel and puts a concentrated load into the bearing,
- the existing masonry is soft, cracked or poorly bonded, as it often is in older solid brick walls, or
- the lintel is an engineered member carrying floor or roof loads.
In those cases the drawing will show the bearing detail, which might be a precast block, a poured concrete bearing, filled cores or a steel plate.
Masonry veneer must sit on the lintel, not hang off it
Bearing at the ends is half the story. The brick also has to sit properly on the horizontal leg along the length of the lintel. Article 9.20.8.5. says masonry veneer of solid units resting on a bearing support must not project more than one-third of the veneer's thickness beyond it. For 90 mm brick, that means no more than 30 mm of the brick can overhang the edge of the angle's horizontal leg.
That is one reason the horizontal leg size in the code tables is matched to the veneer, and why a lintel set too far back behind the face of the brick is a problem even if its ends have plenty of bearing.
Overall lintel length and the longest spans
Lintel length = clear opening + bearing at both ends. With the 150 mm minimum, that's at least the opening plus 300 mm.
| Opening (clear span) | Minimum lintel length at 150 mm each end |
|---|---|
| 0.9 m | 1.2 m |
| 1.2 m | 1.5 m |
| 1.8 m | 2.1 m |
| 2.4 m | 2.7 m |
| 3.0 m | 3.3 m |
These are code minimums for table lintels. Use the bearing length on your drawings if it's longer, and measure the masonry opening on site rather than relying on the window size.
How long can a steel lintel span? In Table 9.20.5.2.-B, the largest angle listed (L178 x 102 x 13) spans up to 4.87 m in 70 mm brick, 4.59 m in 90 mm brick and 4.25 m in 100 mm stone. Beyond that, a veneer opening with a wood stud wall above can use a steel beam from Table 9.20.5.2.-C, which lists a W200 x 36 up to 5.70 m in 70 mm brick, with a steel column at each end and a plate welded to the flange to carry the brick. Anything wider, or carrying floor or roof loads, is designed by an engineer. Wide openings like garage doors are covered in our post on a steel lintel over a garage door.
Bearing on renovations and replacements
Most bearing problems we see come from existing walls:
- Replacing a rusted lintel. The new lintel needs the same 150 mm minimum. If rust has jacked the bearing brick out of place, the bearing is rebuilt first. Our guide to replacing a rusted steel lintel covers what's involved.
- Widening an opening. The new bearings are cut into masonry that was never built for them. Check the pier width at each side before committing to the size.
- Basement windows in block walls. Bearing on hollow block raises the solid-bearing question above. See steel lintels for basement egress windows.
- Flashing at the ends. Flashing over the lintel should run past the ends with end dams so water exits through the weeps instead of soaking the bearing.
Cutting into a loaded masonry wall needs temporary shoring, a qualified designer or engineer, and usually a building permit. Our article on installing a steel lintel in an existing brick wall explains the sequence and who does what.
Ordering a lintel with the right bearing
When you order, give us the clear opening, the bearing length at each end (or the overall length), the angle size, any holes, bolting or welded plates, and the finish. Steel angle lintels supporting masonry must be prime painted or otherwise protected from corrosion (Sentence 9.20.5.2.(4)). We cut, drill and weld lintels to your detail and deliver across the GTA and Ontario.
Send your opening sizes or drawings for a quote, or see our steel products for lintels, beams and plates.
Frequently asked questions
How much bearing does a steel lintel need?
Steel angle lintels sized from the 2024 Ontario Building Code tables need even and level bearing at least 150 mm long at each end, on masonry, concrete or steel (Sentence 9.20.5.2.(3.1)). An engineered lintel may call for more.
Do steel lintels need padstones?
Not as a rule for ordinary veneer openings. The code requires even, level bearing on masonry, concrete or steel. Where the lintel carries heavy loads or bears on hollow block or weak masonry, a designer may specify a solid bearing such as a concrete block, filled cores or a steel plate.
What is the maximum length of a steel lintel?
In the OBC veneer table, the largest angle listed, L178 x 102 x 13, spans up to 4.87 m in 70 mm brick, 4.59 m in 90 mm brick and 4.25 m in 100 mm stone. Wider openings in veneer walls move to the steel beam table or to an engineered design.
How long should a steel lintel be for a 1.2 m window?
At least 1.5 m, which is the 1.2 m opening plus 150 mm of bearing at each end. Measure the actual masonry opening on site and add the bearing shown on your drawings.
