Quality & Site
Common Construction Mistakes That Cause Cracks Later
Why cracks appear one to three years after handover — settlement, shrinkage, thermal movement, poor junctions and rushed curing — and how each is prevented during construction.
Most cracks in a new home are not structural failures; they are the delayed result of a shortcut taken during construction. Knowing the usual causes lets you ask for the specific prevention at the specific stage.
Where cracks come from
| Crack pattern | Usual cause | Prevention during construction |
|---|---|---|
| Diagonal cracks at wall corners near openings | Differential settlement; no lintel band | Soil report, adequate footings, lintels over every opening |
| Horizontal crack where wall meets beam or slab | Shrinkage/thermal movement at the RCC–masonry junction | Chicken mesh across the junction before plaster; delay plaster until masonry has cured |
| Fine map cracks in plaster | Rich mix, rapid drying, no curing | Correct plaster mix, plaster curing for 7 days |
| Cracks along chases | Chases cut after plaster; not filled properly | Chases before plaster, filled and meshed |
| Cracks at terrace parapet base | Slab expansion; no expansion joint | Joint at parapet base, proper coping |
| Slab underside cracks with deflection | Formwork struck early; top steel not held up | Full propping period; chairs for top steel |
| Cracks in AAC block walls | Blocks laid wet; no control joints on long walls | Dry blocks, thin-bed mortar, joints as recommended |
Which cracks need an engineer
Hairline plaster cracks under about 1 mm that do not grow are cosmetic. Cracks that widen over weeks, run diagonally through masonry, appear in beams or columns, or coincide with doors that no longer close should be looked at by a structural engineer. Marking the crack ends with a dated pencil line is a simple way to know if it is moving.