Lintel replacement
The steel angle carrying the brick above your window rusts, and rusting steel swells. That swelling is what cracks the courses above your windows and lifts the brick off level.
What a lintel is and why it fails
Above every window and door in a brick building there is something holding up the brick that would otherwise be sitting in mid-air. In most Chicago housing stock that something is a steel angle — an L-shaped length of steel bedded into the wall, spanning the opening.
Steel in a wet wall rusts. The specific problem is that rust occupies substantially more space than the steel it replaces, so a rusting lintel does not quietly get thinner and weaker. It gets bigger, and it does so inside a wall that has nowhere to give. Something has to move, and what moves is your brickwork.
How to spot it from the ground
- Rust-coloured staining bleeding down the brick or the joint directly above a window
- A horizontal crack running along the mortar joint just above an opening
- The course of brick above a window sitting visibly higher than the same course either side of it
- Flaking, layered orange metal visible in the gap above the window frame
- Windows that have started to stick or bind for no obvious reason
The staining tends to arrive first and the cracking follows. If you have both, the steel has been working on that wall for a while.
What the replacement involves
The brick above the opening is supported, the old steel is cut out, a new lintel goes in, and the masonry above is rebuilt and repointed back into the surrounding wall. Where the brick that came out is sound it goes back; where the rust has already cracked it, we replace it and match it.
The part that matters and does not show is what goes in around the new steel. Put fresh steel back into the same wet detail and you have bought yourself the same job again in fifteen years. The point of the exercise is that the new one stays dry.
Why this one should not wait
Most masonry problems are patient. This one compounds. Rust that is expanding is applying continuous pressure to the brickwork above it, and every winter adds to the crack that pressure has already opened — which then lets in more water, which accelerates the rust.
Caught while it is a stain and a hairline joint, it is one opening and a day. Left until the courses above have moved, you are paying for the lintel and for a section of rebuilt wall on top of it.
Get a lintel price
Estimates are free and there is no obligation attached to one. Tell us what you are seeing and we will tell you what it actually needs.