Signs Your Garage Lintel Needs Repair

Lintel failure is slow. The steel above your garage door corrodes over years, not weeks, which means there is a long window where the problem is visible and still inexpensive to fix. Here is what to look for, roughly in the order most homeowners notice it.

1. A Horizontal Crack Directly Above the Door

This is the classic one. A crack running along the mortar joint immediately above the garage opening, straight and horizontal rather than jagged, sometimes running the full width of the door. That line is where the expanding rust on the lintel is pushing the first brick course upward. If you only ever learn one sign, learn this one.

2. Stair-Step Cracking From the Corners

Cracks that climb diagonally from the top corners of the opening, following the mortar joints in a staircase pattern up and outward. This is the wall shedding load around a lintel that is no longer carrying its share, and it usually indicates deflection — the steel sagging — rather than rust alone.

3. Rust Staining on the Brick

Orange or brown streaks bleeding downward from the mortar joint above the door. This is the most direct evidence available from ground level: it is the lintel itself, dissolved in rainwater, running down the face of your house. Brick does not produce rust stains on its own.

4. A Brick Course That Is No Longer Level

Sight along the mortar line above the garage door from one side, at a shallow angle, the way you would sight down a board for a bow. A course that dips in the middle or bulges outward is telling you the steel underneath has moved. This one is easy to miss looking at the wall straight-on and obvious from the side.

5. A Gap Opening Above the Door Frame

A visible separation between the top of the garage door frame and the brick above it, often first noticed because a bead of caulk that used to seal it has torn. Where the gap is wider at one end than the other, the wall is moving unevenly.

6. The Garage Door Itself Starts Behaving Differently

Doors are precise instruments and they report structural movement early. Watch for a door that binds partway through its travel, a top weather seal that no longer meets evenly across the width, or an opener that has started straining or reversing when nothing about the door has changed. When the opening racks even slightly out of square, the door is the first thing to notice.

7. Daylight or Draft at the Header, From Inside

Stand inside the garage with the door closed and the lights off, and look along the top of the opening. Daylight where there should be none — or a noticeable draft in winter — means the assembly above the door has separated enough to open a path through the wall. This is a late sign, not an early one.

Telling Lintel Failure From Foundation Settlement

Both crack brick, and both crack it around openings first. Getting this wrong is expensive in both directions, so it is worth a careful look before you decide what you are dealing with.

The most reliable distinction is how far the evidence spreads. Lintel failure is confined: the damage lives above one opening, the rest of the house is unremarkable, and there is often rust staining to confirm it. Settlement is systemic, and if it is the cause you will usually find corroborating evidence elsewhere.

• Cracking at more than one opening, or in walls with no opening at all
• Interior doors that stick or swing open on their own, in more than one room
• Floors that feel sloped, or a noticeable bounce underfoot
• The chimney separating from the wall of the house
• Cracks that are visibly wider at one end than the other, indicating rotation
• Gaps opening where trim meets the ceiling or where the floor meets the baseboard

One opening cracking, with rust staining: most likely a lintel. Several openings cracking, doors sticking through the house, floors out of level: treat it as a foundation question first. Replacing a lintel on a settling house fixes the symptom and leaves the cause running.

How Urgent Is It?

A hairline horizontal crack with no displacement is worth monitoring and planning around, not panicking over. What raises the urgency is movement: a crack that is measurably wider than it was six months ago, brick that has shifted out of plane, or any course that has begun to sag. Masonry above an opening is held up by the lintel and by its own arching action, and once brick starts displacing, that second mechanism is what is left.

A practical way to track it: photograph the crack with a coin or tape measure held against it for scale, note the date, and repeat in a few months. That record is genuinely useful to whoever assesses it, and it turns an argument about whether it is getting worse into a matter of fact.

If you are seeing two or more of the signs above, it is worth having someone look. Triangle Reconstruction covers Wake and Durham counties and every county bordering them — call (919) 924-7600.