BUILDING INSPECTION GUIDE
Internal Horizontal Cracking
Horizontal cracking to internal walls can develop for several reasons. The location, length and pattern of the cracking, together with the construction of the wall and other visible defects, help provide context during a building inspection.
UNDERSTANDING THE DEFECT
What Does Horizontal Wall Cracking Mean?
Horizontal cracking describes cracking that runs predominantly across a wall rather than vertically or diagonally. It can occur within plaster, render, masonry or at junctions between different building materials.
The presence of horizontal cracking does not establish one particular cause. Depending on the building and location, it may be associated with movement, shrinkage, material junctions, construction details or stresses within the wall.
For this reason, the crack should not be assessed in isolation. Its position within the building and its relationship with other visible defects are important when considering its significance.
WHAT WE CONSIDER
Factors That Help Explain Horizontal Cracking
Several observations can help determine whether the cracking appears isolated or forms part of a broader pattern of building movement.
Cracking near ceilings, openings, wall junctions or particular construction elements can provide useful context.
The extent and width of the crack are considered together with its position and surrounding defects.
Plasterboard, masonry, render and other finishes can respond differently to movement and shrinkage.
Binding, misalignment or cracking around openings may indicate that movement extends beyond one wall.
Changes at floor, ceiling or cornice junctions may help establish whether a wider movement pattern exists.
Patching, repainting or repaired cracking can provide evidence that the condition has occurred previously.
POSSIBLE CONTRIBUTING FACTORS
Why Internal Walls Can Develop Horizontal Cracks
Internal wall cracking can be influenced by normal material movement, shrinkage, differential movement within the building, changes in supporting ground conditions or movement between different construction materials.
Where walls meet structural elements or different materials, small amounts of movement can sometimes become visible along the junction. In other situations, cracking may form part of a broader pattern involving floors, ceilings, external masonry or openings.
The surrounding conditions therefore matter. Looking only at the crack itself can lead to an incomplete assessment of what may be occurring.
WHAT WE CHECK
Horizontal Cracking During a Building Inspection
Where horizontal cracking is present, we consider the visible defect together with the surrounding wall, adjacent rooms and other accessible areas of the building.
The aim is to determine whether the cracking appears localised or whether there are additional visible signs that may indicate a wider movement issue.
PUTTING THE FINDING IN CONTEXT
Cracking Should Be Assessed as Part of the Building
An isolated crack and a repeated pattern of cracking across several areas can have very different implications. The surrounding building conditions help determine what level of attention may be appropriate.
Where horizontal cracking is significant, unusual, widespread or associated with other signs of movement, further investigation by an appropriately qualified structural engineer or other relevant specialist may be recommended.