Lintel Failure: The Hidden Threat Above Your Windows and Doors
If you see a horizontal or stair-step crack in the brick above a window or door, you are almost certainly looking at a lintel failure. This is one of the most common — and most commonly misunderstood — structural masonry issues in Cleveland.
What Is a Lintel?
A lintel is a structural member that spans the opening above a window or door, supporting the weight of the masonry above. In most Cleveland residential construction, lintels are steel angles — L-shaped pieces of steel embedded in the mortar joint above the opening.
Why Lintels Fail
Steel corrodes. When moisture reaches the steel lintel — through cracked mortar, failed caulk, or missing flashing — the steel begins to rust. As it rusts, it expands. Steel can expand up to 10 times its original volume as it converts to iron oxide (rust).
This expansion creates enormous pressure on the surrounding masonry, causing:
- Horizontal cracks along the mortar joint at the lintel line
- Displacement of brick courses above the lintel
- Stair-step cracks radiating from the corners of the opening
- Bowing of the brick face above the window
By the time these cracks are visible, the lintel has been corroding for years. The visible damage is the late-stage symptom of a process that started long before.
Why Patching Does Not Work
Repointing the cracks above a window without addressing the corroded lintel is pointless. The expansion pressure will crack the new mortar within one to two seasons. The only permanent solution is lintel replacement.
Proper Lintel Replacement
- Shore the masonry above the opening to prevent collapse during removal
- Remove the brick at the lintel line to expose the corroded steel
- Remove the corroded lintel completely
- Install a new galvanized or stainless steel lintel with proper bearing on each side of the opening (minimum 4 inches)
- Install proper flashing above the new lintel to direct water away from the steel
- Replace the brick with matching units and compatible mortar
- Repoint any remaining cracked joints above and below the opening
The Cost of Deferral
Lintel failure is progressive. The longer it is deferred, the more masonry is damaged by the expanding steel. A lintel replacement caught early may involve removing and replacing 10-15 bricks. A lintel replacement deferred for years may require rebuilding the entire section of wall above the opening.
The Veteran Masonry Standard
We assess every lintel we encounter — not just the ones with visible cracks. During any repointing or repair project, we probe lintels for corrosion and recommend replacement when deterioration is found, even if cracks have not yet appeared.
Proactive lintel replacement is one of the highest-value masonry investments a Cleveland homeowner can make. It prevents the cascading damage that turns a $1,500 repair into a $5,000 rebuild.
Cracks above your windows? Request a free estimate [blocked] or call (216) 213-5403.