Replacing a Rusted Steel Lintel: Process and What Drives the Cost

Steel lintel replacement means shoring the wall, removing the brick above the opening, taking out the corroded lintel, setting a new protected lintel on sound bearing, flashing it, and rebuilding the masonry. It is masonry contractor work, with a designer or engineer involved when the wall carries floors or roof or when anything about the opening changes. What it costs depends far more on the opening, the wall and access than on the steel. Here is how to recognize a failing lintel, decide between repair and replacement, and understand what you are paying for.

Signs your steel lintel is rusting

Steel lintels sit hidden in the wall, so the first clues usually show up in the brick around them:

• Rust staining running down the brick from the window or door head
• Flaking or layered rust on the visible edge of the angle
• A horizontal crack in the mortar joint along the top of the lintel
• Stair-step cracks running up and away from the top corners of the opening
• Brick lifting or bulging above the opening, or mortar joints opening up
• A sagging lintel or brick that has dropped at mid-span
• Windows or doors that stick because the head of the opening has moved

When steel rusts, the rust takes up more space than the steel it came from. Layers of rust building up between the lintel and the brick can push the masonry up and out, which is why corroded lintels crack walls even before they lose much strength. Cracks around openings can also come from foundation movement or other causes, so a cracked wall needs to be looked at by someone qualified before you assume it is the lintel.

Why lintels rust

A steel lintel kept dry lasts a long time. Lintels rust when water reaches them and stays there. The usual causes:

• Missing or failed flashing. The 2024 Ontario Building Code requires flashing over masonry openings in most situations, extending from the front of the masonry up behind the lintel. Many older walls have none, or flashing that has deteriorated.
• No weep holes, or weep holes blocked with mortar droppings, so water collects on the lintel instead of draining out.
• Poor or missing coating. The code requires steel angle lintels supporting masonry to be prime painted or otherwise protected from corrosion. Older lintels may have had little protection to begin with.
• Water sources above, such as failed sills, leaking eavestroughs, open mortar joints or caulking gaps at the window head.
• Age. Even a well-built detail wears out over decades.

Fixing the water problem is half of any lintel repair. A new lintel in the same leaky detail will rust again.

Repair, retrofit or replace?

Not every rusty lintel has to come out. The options, roughly from least to most work:

The decision depends on how much steel is left, which can only be judged by exposing and inspecting it. An engineer or experienced masonry contractor should make the call. If several openings on the same wall show signs, they often share the same detail and the same problem, so check them all.

How the replacement works

Replacement follows the same sequence as installing a new lintel in an existing wall, which we cover step by step in how to install a steel lintel in an existing brick wall. What is different on a replacement:

• The old lintel has to come out. Heavily rusted steel may be bonded to the brick by corrosion and need cutting or grinding to free it.
• The bearing needs checking. Rust often damages the brick at the ends where the lintel bears. The new lintel needs at least 150 mm of even, level bearing on sound masonry, concrete or steel when sized from the code tables, so damaged bearing brick is rebuilt first.
• The size gets re-checked. Replace with a lintel that suits the opening and the wall, not just a copy of the old one. Our guide to steel lintel sizes under the Ontario Building Code explains the tables.
• The finish gets upgraded. Hot-dip galvanized lintels are a common choice on replacements, since the wall has already shown it lets water reach the steel.
• The flashing gets done properly, with weep holes and end dams so water drains out instead of sitting on the new steel.
• The window may need attention. The head of the opening is disturbed, so coordinate with whoever will reseal or replace the window or door.

Permits and safety

Lintel replacement is structural repair. Under Ontario's Building Code Act, construction includes material alteration and repair, and a permit is required for construction, so ask your building department whether your job needs one. Treat the wall as unsafe until it is shored: a badly corroded lintel may already be close to failing, and removing brick around it without support can let the masonry above drop. This is not a do-it-yourself job.

What drives the cost of lintel replacement

We don't publish prices because every replacement is different, but these are the factors that move the number:

• Opening width. Wider openings mean more brick to remove and rebuild, heavier steel and more shoring.
• Number of lintels. Doing several openings in one mobilization costs less per opening than separate visits.
• Wall type. Solid load-bearing masonry needs more shoring and often engineering. Veneer is usually simpler.
• Access and height. Second-storey openings need scaffolding. Tight side yards, decks and landscaping slow the work.
• Brick and mortar matching. Older brick can be hard to match, and salvaging the original brick takes care.
• Stone sills, arches or decorative work that must be removed and reset.
• Interior repairs to plaster, drywall and trim disturbed from inside.
• Condition of the bearing ends and how much rebuilding they need.
• The new lintel itself: size, length, fabrication and finish.
• Engineering and permit, where needed.
• Season. Cold-weather masonry needs heat and enclosures.

For a breakdown of the steel side of the price and how to compare quotes, see steel lintel cost in Ontario.

Getting quotes for lintel replacement

Ask each masonry contractor to quote the same scope in writing:

1. Which openings, and whether the work is repair or full replacement
2. Shoring method
3. Lintel size, length and finish, and who supplies it
4. Flashing, end dams and weep holes
5. Brick salvage or matching, and mortar colour
6. Interior repair, clean-up and disposal
7. Permit and engineering, if required
8. Schedule and weather protection

Quotes that skip flashing or use an unprotected lintel will be lower, but they set you up for the same failure again.

Ordering replacement lintels

Contractors and homeowners can order replacement lintels from us cut to length and drilled or welded as the detail requires. Tell us the finish your designer wants when you ask for a quote. We deliver across the GTA and Ontario, and engineering services are available for projects that need them. Send the opening sizes, wall type and any engineer's detail, and we will quote the steel.

Request a quote for replacement lintels, or see the steel products we fabricate. For ordering tips, read our guide to custom steel lintels in Ontario.