Wall cracks: when should you be concerned?
Cracks in walls are common in buildings, whether old or new. While some are purely cosmetic, others can reveal more serious structural disorders. Knowing how to identify and interpret them is essential to prevent any risk to the soundness of the structure and the safety of its occupants.
The different types of cracks
Not all cracks are the same. Here are the main categories:
- Surface cracks (or shrinkage cracks): fine and shallow, they often appear in render or paintwork. Generally not serious.
- Vertical or horizontal cracks: these may signal movement in the structure (expansion, differential settlement…).
- Stepped cracks: visible on brick or concrete-block walls, they follow the joints and are often linked to subsidence of the foundations.
- Through cracks: these affect the full thickness of the wall. They are the most concerning.
When should you be concerned?
It is time to call in an expert when:
- The crack exceeds 2 mm in width
- It changes over time (in length or width)
- It appears suddenly with no apparent cause
- It is accompanied by other signs (doors that no longer close properly, sloping floors, etc.)
- It is located on a load-bearing wall or near the foundations
These signs may indicate a structural problem such as ground movement, foundation subsidence or unevenly distributed mechanical stresses.
Possible causes
Cracks can be caused by:
- Ground movement (swelling clay, drought, differential settlement)
- Construction defects
- Water infiltration or poor rainwater drainage
- Nearby works or repeated vibrations
- Natural ageing of materials
How should you react?
Before any repair work, it is crucial to establish a precise diagnosis. Filling a crack without knowing its cause is like putting a plaster over an untreated problem.
At AC Expertises, we carry out detailed inspections of cracks in residential buildings, analysing their causes, assessing the risks, and providing clear recommendations for lasting repairs. In the event of a dispute, we can also assist in an amicable or judicial context.
Do not let a crack become a hazard. Call in an expert at the first warning signs.