Small, hairline cracks are common and not usually concerning. These are often the result of seasonable expansion and contraction of soils beneath a structure’s foundations over time. These types of cracks can usually be easily patched over and repainted.
However, larger cracks that display the following characteristics may indicate weaknesses in your property’s foundation and mean that you should seek expert advice:
Large cracks that start at windows, doorways or corners of buildings
Cracks are wider than about 5mm (or half a centimetre)
Cracks that are jagged, horizontal or vertical, zig-zagged, stepped in brickwork, or follow mortar lines
Pay attention to other warning signs such as sinking or sloping floors, cracks in paths and driveways as these may be signs of structural issues caused by subsidence. Windows and doors becoming jammed or misaligned, skirting boards separating from the wall or the formation of puddles around the perimeter of your home may also indicate foundation ground issues.