Lintels are structural elements used above doors, windows and other openings in masonry. When a lintel or the surrounding construction begins to deteriorate, the brickwork may crack, move or become distorted.
The cause cannot normally be confirmed from the visible crack pattern alone. Choose the question that most closely matches your situation for a quick overview and more detailed guidance.
What do you need to know?
Does my lintel need replacing?
Not necessarily. Replacement becomes more likely where the lintel is heavily corroded, distorted, unsuitable for the load or associated with continuing masonry movement.
Important: cracking alone cannot confirm that replacement is required.
Can a failed lintel be repaired?
Sometimes. A repair may be possible where deterioration is limited, the existing support remains adequate and the underlying cause can also be corrected.
Important: repairing the visible crack does not necessarily resolve the structural defect.
Is lintel failure dangerous?
A crack does not automatically mean that collapse is imminent. Loose masonry, widening gaps, rapid movement or visibly dropping brickwork require prompt professional assessment.
Take care: do not disturb masonry that appears loose or unstable.
How much might repair or replacement cost?
The total depends on access, scaffolding, temporary support, wall construction, lintel specification and how much masonry and finishing work is required.
Check quotations for: VAT, scaffolding, engineering, making good and internal finishes.
Does my lintel need replacing?
Not every crack above a window or doorway means that the lintel must be replaced. Cracking can also result from settlement, thermal movement, moisture, subsidence, frame movement or defects elsewhere in the wall.
The condition of the lintel, the surrounding masonry and the wider structure must therefore be considered together.
Replacement becomes more likely where the lintel has lost structural capacity, no longer provides adequate support or was not suitable for the loading and wall construction in the first place.
Repair may be considered when...
- The movement is limited and is not continuing to progress.
- The surrounding masonry remains comparatively stable.
- Corrosion, spalling or cracking is localised.
- The lintel retains adequate structural capacity.
- The underlying cause can also be identified and corrected.
Replacement becomes more likely when...
- A steel lintel is heavily corroded, distorted or materially reduced in section.
- A concrete lintel has extensive cracking, spalling or reinforcement corrosion.
- The masonry is badly displaced or continues to move.
- The existing lintel is unsuitable for the actual span, wall construction or loading.
- Previous alterations have removed support that the opening formerly relied upon.
These indicators should not be used as a product-selection checklist. Whether repair or replacement is appropriate should be determined from the actual structure, rather than from the visible crack pattern alone.
Can a failed lintel be repaired?
Some lintel and masonry defects can be repaired without completely removing the existing lintel. The suitability of a repair depends upon what has caused the movement and how much structural capacity remains.
Possible repair approaches may include proprietary masonry-reinforcement systems, localised concrete repairs, corrosion treatment or strengthening designed for the particular opening.
Repairing the visible crack alone is not sufficient. Moisture ingress, inadequate bearing, unsuitable loading, damaged cavity trays or wider structural movement may continue to affect the opening after the masonry has been repointed.
A repair system should only be used within its documented application and design requirements. It should not be assumed that reinforcement installed within mortar joints can replace any failed lintel in any wall.
Is lintel failure dangerous?
A crack above an opening does not by itself show that the wall is at immediate risk of collapse. Buildings can develop minor cracks through settlement, seasonal movement and changes in moisture or temperature.
The concern increases when movement is continuing, masonry is becoming loose or the load above the opening is no longer being transferred correctly to the supporting wall.
Cracks appearing on both the internal and external faces of the wall may indicate more than a superficial defect in the finish.
Where masonry appears loose or unstable, avoid disturbing the wall or carrying out cosmetic repairs until the opening has been inspected and made safe.
What affects the cost of lintel repair or replacement?
Repair and replacement costs vary considerably because the price of the lintel itself is usually only one part of the work.
A single national average can be misleading unless it states what type of repair, access and reinstatement are included.
Access and scaffolding
Upper-storey openings, restricted areas and work above conservatories or extensions may require specialist access.
Cost impact: scaffolding and access can form a substantial part of the total price.
Temporary structural support
The masonry and loads above the opening must be supported before the lintel is removed or the wall is extensively disturbed.
Cost impact: larger openings and more complicated loads generally require more involved temporary works.
Wall construction
A solid wall, cavity wall, rendered elevation or unusual masonry construction can require different levels of opening-up and reinstatement.
Cost impact: cavity trays, insulation, damp protection and finishes may all need to be restored.
Lintel specification
The required product depends on the opening, wall construction, bearing conditions and loads supported above it.
Cost impact: wider openings, higher loads and specialist lintels can increase material and design costs.
Extent of masonry work
Some replacements require only limited local rebuilding, while others involve extensive removal of damaged or displaced masonry.
Cost impact: brick matching, repointing and rebuilding can add significant labour.
Professional and finishing costs
Structural assessment, plaster repairs, decoration and disposal may be priced separately from the main masonry work.
Cost impact: quotations should be checked carefully to establish what is included.
Limited masonry reinforcement may cost substantially less than complete lintel removal and replacement, but the two forms of work are not directly comparable.
A meaningful cost range should state whether it includes the lintel, labour, scaffolding, temporary support, structural assessment, cavity details, making good, VAT and internal decoration.
What are the warning signs of lintel failure?
The symptoms below do not prove that the lintel has failed, but they can indicate that the opening and surrounding masonry should be examined more closely.
Sticking doors or windows
Movement around an opening can distort the frame and make a door or window more difficult to operate.
Look for: the problem returning after the frame has already been adjusted.
Diagonal cracking
Cracks may begin near the upper corners of an opening and travel diagonally through the mortar joints.
Look for: cracks at both ends or cracks that continue to widen.
Gaps or bowing masonry
Movement can push bricks out of alignment or create a gap between the lintel and the masonry above it.
Look for: displaced, bulging or loose brickwork around the opening.
Rust staining
Rust marks on render, brick reveals or exposed concrete can indicate corrosion within steel or reinforced concrete.
Look for: staining accompanied by cracking, spalling or opened mortar joints.
Sticking doors and windows
One possible warning sign is a door or window that becomes increasingly difficult to open or close. Problems around window lintels may first become noticeable through movement of the frame or cracking around the opening.
- Pressure and movement around the opening can distort the frame.
- If the fitting has been adjusted but the problem returns, the cause may be within the surrounding structure.
- Cracked glass or failed sealed units may occasionally accompany distortion, although they can also have other causes.
Sticking can also result from moisture, worn hinges, swelling timber or problems with the frame itself. It should therefore be considered alongside other evidence.
Cracking through mortar joints
Cracks can appear where mortar has separated from the edge of the brickwork around an opening.
- A short, isolated crack may result from general settlement or seasonal movement.
- Cracks at both ends of an opening may be more concerning, particularly where they travel diagonally away from the corners.
- Repeated repointing that fails again suggests that the underlying movement has not been resolved.
Gaps, displacement and bowing
Distorted or displaced masonry indicates that the wall is no longer remaining in its original alignment.
- Bricks may be pushed or pulled out of position around the opening.
- A gap may appear between the lintel and the first course of masonry above it.
- Mortar joints may open, compress or become uneven in different areas.
Opened joints can also allow additional moisture into the wall, potentially accelerating corrosion and deterioration.
Rust staining and corrosion
Rust marks on render, brickwork or concrete may point to corrosion within a steel or reinforced-concrete lintel.
- Many modern steel lintels use galvanised protection, but damage or prolonged exposure to moisture can reduce durability.
- Older lintels may have relied upon paint or less extensive corrosion protection.
- Where moisture reaches reinforcement inside concrete, rust expansion can crack and displace the surrounding material.
Easing a door or repointing a crack may improve the immediate appearance, but it will not correct continuing structural movement or corrosion.
Why do lintels fail?
Lintel-related defects can result from deterioration of the product, problems within the surrounding wall, unsuitable installation or changes to the structure after the lintel was installed.
Installation defects
A lintel may not perform as intended where it has inadequate bearing, has been positioned incorrectly, has been damaged or was not suitable for the wall construction and loading.
A modern cavity wall lintel also forms part of a wider moisture-management arrangement. Cavity trays, damp protection and weep vents may be required to direct water safely out of the wall.
If relevant moisture-management details are missing, damaged or incorrectly installed, water may remain around the lintel and increase the risk of deterioration.
Corrosion of steel lintels
Steel lintels exposed to persistent moisture or aggressive environmental conditions may deteriorate over time.
Some older buildings contain painted or ungalvanised steelwork. As corrosion develops, the steel expands and can exert pressure on the surrounding masonry.
This may contribute to horizontal cracking, opened mortar joints and displacement of brickwork. Once the wall opens, additional water can enter and accelerate the problem.
Corrosion within concrete lintels
Concrete lintels normally contain reinforcement that contributes to their tensile capacity.
Where moisture reaches this reinforcement, corrosion products occupy more space than the original steel. The resulting pressure can cause cracking, spalling and sections of concrete to break away.
Changes in structural loading
A refurbishment, extension or loft conversion can alter the loads carried by existing lintels.
An existing lintel may not have been designed for those additional forces, even where it performed adequately under the original building arrangement.
Where the structure or use of a building has changed significantly, the opening may require a project-specific structural assessment rather than a like-for-like product replacement.
Replacement windows and lost frame support
Some older openings may have relied in part upon the original timber or steel frame for support.
When that frame is removed and replaced with a different type of window, the change can expose inadequate or missing structural support above the opening.
The replacement arrangement must be assessed on its own merits. It should not be assumed that a new frame can carry loads previously supported by the original construction.
Ground movement and subsidence
Cracking around a lintel does not always originate at the opening. Changes in ground conditions, flooding, nearby development or subsidence can redistribute loads through the building.
Lintel-level cracking may therefore be one symptom of a wider structural movement problem.
Other signs can include vertical cracks, stepped cracking extending through several courses or cracks passing directly through bricks. In these circumstances, the wider building should be assessed rather than treating the lintel in isolation.
Missing or concealed structural support
Some older buildings relied upon steel window or door frames rather than a separate, readily visible lintel.
During refurbishment, removal of the original frame may reveal that little or no independent support exists above the opening.
A suitable support arrangement may therefore need to be designed before the original frame is disturbed.
What normally happens during lintel replacement?
Lintel replacement involves temporary structural support, removal and rebuilding of masonry, correct product specification and reinstatement of the wall’s weather and moisture-management details.
The following is a high-level overview of the work rather than an installation method. The temporary works, lintel specification and sequence must be determined for the individual structure.
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Assess the opening and diagnose the cause
The lintel, masonry, frame and wider wall are examined to establish whether the problem is localised or part of broader structural movement.
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Establish the wall construction and loading
The clear opening, wall build-up, support conditions and loads above the opening are considered before a replacement product is selected.
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Specify the replacement lintel
The lintel must be suitable for the actual structure. Manufacturer technical information should be applied to the confirmed project conditions rather than used as a substitute for establishing them.
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Plan safe access and temporary support
A suitable arrangement is prepared to support the masonry and loads while the existing lintel and surrounding brickwork are disturbed.
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Open the wall and remove the existing lintel
The necessary masonry is carefully removed and the condition of the bearings and surrounding construction is checked.
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Install the replacement and associated details
The new lintel is installed as specified, together with the required moisture-management, insulation and cavity details.
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Rebuild and reinstate the wall
Masonry, mortar joints, weep provision, finishes and other disturbed elements are reinstated as required.
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Complete the work and remove temporary support
Temporary support is removed only when the repaired construction is ready and the responsible contractor is satisfied that the load can be carried safely.
Temporary support is project-specific
Removing an existing lintel is structural work. The load above the opening will normally require temporary support before masonry is removed.
Equipment may include adjustable steel props, masonry-support attachments and suitable access equipment, but the arrangement cannot be selected from the product type alone.
An access scaffold may also be required where the work cannot be carried out safely from ground level.
Who should inspect or replace a lintel?
The person assessing the cause and structural adequacy may not be the same person who carries out the physical work.
Structural engineer
May assess structural loading, altered load paths, significant movement and the requirements for a replacement or strengthening design.
Often appropriate when: loading is uncertain, the building has been altered or movement is substantial.
Experienced building surveyor
May investigate defects, assess the wider condition of the building and advise whether specialist structural input is required.
Often appropriate when: the cause is uncertain or several building defects may be involved.
Masonry or structural-repair contractor
May carry out the repair or replacement once the scope, lintel and temporary-support requirements have been established.
Look for: relevant experience with the wall type, access conditions and proposed repair system.
For relatively straightforward work, an experienced contractor may coordinate assessment, supply and installation. Where there is uncertainty about structural loading, subsidence, previous alterations or extensive movement, separate professional input may be required.
What repair methods may be considered?
The appropriate repair depends upon the lintel material, wall construction and underlying cause. The descriptions below are general categories rather than instructions for carrying out the work.
Proprietary masonry reinforcement
Some repair designs use stainless-steel reinforcement installed within masonry joints to stabilise or strengthen the area above an opening.
The suitability of a system depends upon its documented application, the condition of the existing support, the masonry and the cause of the movement.
It should not be assumed that this form of reinforcement can replace any damaged or missing lintel.
Steel lintel repair or replacement
A steel lintel may sometimes remain in place where an engineered repair can restore an appropriate support arrangement.
Where corrosion is extensive, the steel is distorted or significant section has been lost, removal and replacement may be considered more appropriate.
The replacement must be specified for the actual wall construction and loads. Visual similarity to the existing lintel does not establish that a like-for-like product is suitable.
Concrete lintel repair
Localised concrete deterioration may sometimes be repairable where the remaining lintel is structurally adequate.
A suitable repair requires assessment of the reinforcement, corrosion, remaining concrete and cause of water ingress. Applying a general-purpose repair material to the visible damage does not by itself restore structural capacity.
Extensive cracking, spalling or reinforcement corrosion may make replacement more appropriate than local repair.
Timber and stone lintel repair
Timber and stone lintels are commonly associated with older or traditionally constructed buildings and can require specialist assessment.
Possible approaches may include localised repair, concealed reinforcement, partial replacement or complete replacement, depending upon the material condition, loading and significance of the original fabric.
What should you do next?
If you have noticed cracking, distortion or corrosion around an opening, dated photographs can provide a useful record of the visible condition.
However, monitoring should not delay professional assessment where movement appears active, masonry is loose or the cause is uncertain.
Planning a lintel replacement?
Establish the structural requirements before selecting the product
Wade supplies a broad range of lintels and associated building products. Our team can discuss available product ranges and manufacturer technical information, but the lintel must be specified for the actual wall construction, opening and loading conditions.
