Many Sydney homeowners have noticed new or worse cracks appearing just in the last month or so.Ī jagged crack winds its way along the external brickwork of this hundred-year-old house in north-west Sydney, January 2020. 'This is an extreme event, and there's no surprise there's a correlation to soils around the country being drier than they've ever been before and the drought,' said Professor Fityus. 'Soils continue to be extremely dry along the east coast of New South Wales and the fraction of the state experiencing very much below average soil moisture in December has increased to 48 per cent compared to 25 per cent in November,' the bureau said in its December drought report.Īs the soil beneath us dries up, plants and trees are trying to stay alive, desperately sucking up whatever moisture they can get from the ground, which is drying the soil even more. That heat and dryness is not confined to the atmosphere around us - soil moisture content in December was also 'very much below average' in parts of every state and territory except the ACT, according to BOM data.

The Bureau of Meteorology (BOM) has confirmed that last year was Australia's hottest and driest year on record, with varying parts of Australia having been in drought since 2017. 'We've got this rare occasion now where we're going without rain, significant rainfall, for months or, in some places, 12 months and that means we have long periods where soil, which would otherwise not lose its moisture, is now losing its moisture,' explained Stephen Fityus, a professor of geotechnical engineering at the University of Newcastle. In the vast majority of cases, cracks in houses are caused when the soil underneath the house starts to dry and contract, causing the footing of the house to shift unevenly, which leads the walls to move and crack.Ĭlay soils are much more susceptible, or 'reactive', to changing moisture content than sandy soils because, like a sponge, they soak up or repel water. 'In extraordinary dry times like now, those cracks will widen,' warned Professor Nasser Khalili, the head of geotechnical engineering at the University of New South Wales. As a record-breaking drought continues to overwhelm large parts of Australia, more of these kinds of cracks are appearing in homes throughout the country.

But crack splitting