Wet weather and soggy, muddy conditions are often blamed as the primary culprit for structural issues in our homes. However, the truth is that prolonged dry periods can be just as harmful to the stability of our foundations.
According to civil engineer and Mainmark business development manager James O'Grady, extended dry spells have a significant impact on the ground and subsequently, on building foundations.
"Many Australian homes are built on sandy or reactive clay soils which shrink and swell in response to temperature and moisture levels," he said.
"There are many suburban homes across Australia that experience cracks in the walls following months with little to no rainfall."
This trend is seen around the world. During the UK's record-breaking summer in 2019, the lack of rain and other heatwave conditions caused water from subsoils to dry out. This resulted in soil shrinkage that affected building foundations and created a subsidence surge.
Subsidence occurs when the ground changes, causing the home to gradually settle in one area or across the entire footprint.
It is a common geological phenomenon in Australia. The combination of significant drought conditions, with occasional heavy rainfall, can create varying moisture levels in the soil that cause foundations to shift.
Subsidence is not a concern unique to any one state or region - soil attributes are similar across the entire country, especially where people prefer to live.
This means homes across Australia are subject to ground conditions that cause soil swelling and shrinkage following extended dry weather.
Mr O'Grady said the signs of subsidence may not be immediately obvious or limited to wall cracks, so it helps to know what else to look for.
"Sinking or sloping floors may also indicate structural settlement. Windows and doors becoming jammed or misaligned, skirting boards separating from the wall or puddles forming around the exterior walls of the home may all indicate foundation ground issues."
Luckily, there are solutions that can prevent or reverse the effects of subsidence.
Cementitious fills and specialised resin mixes can be applied beneath a home to re-level its foundations and strengthen the ground, eliminating the risk of ground conditions that affect structural integrity.
It is important to recognise the signs of subsidence early and act without delay.
Not all wall cracks are the same - the type, size and location of cracking is important to consider when identifying the likely cause.
In addition to subsidence, building movement may also be caused by other underlying or site-specific issues which require a professional assessment and working knowledge of the local area.
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