Holes and Voids Resi

How climate change may affect your property’s foundations

Climate change is often associated with cataclysmic weather events and temperature changes but it can also have more subtle, long-term effects on our homes.

Scientific research over the decades has revealed that the earth’s average temperature has gradually increased due to the greenhouse gases that are trapped in the atmosphere. This is particularly noticeable in warmer environments, like Australia, where an unnaturally altered climate is resulting in drier conditions for longer periods of time combined with sudden and heavy bouts of extreme wet weather. For the majority of Australia’s housing stock, which is built on moderately to highly reactive clays, this is especially challenging.

Reactive clays are prone to seasonal ground movement due to changes in the soil’s moisture levels which swell in winter as they absorb excess moisture and shrink in summer when conditions are usually drier. While the constant movement caused by expansion and contraction in the ground can contribute to foundational shifts and slab movement, the reaction is exacerbated by the prolonged drier conditions and heavy wet weather events which can be attributed to climate change.

The truth about wet conditions

Flooding caused by intense storm activity can have a direct impact on a property’s foundations or concrete slabs, resulting in damage. While water that moves slowly through clay during a single heavy storm is unlikely to have an adverse effect on a building, ongoing wet weather can accelerate the movement of water through the clay which is more likely to create drainage issues. These extended periods of rain cause the clay beneath the ground’s surface to become oversaturated and therefore too fluid and weak to provide consistent support to the building’s footings.

In addition to residential homes, it is not uncommon after periods of heavy rain for commercial warehouses and transport yards to notice concrete slab movement when the ground begins to dry out.

To prevent damage to a building, it is important to consider the relationship between weather events and climate change, being aware of the current conditions and paying closer attention to general home maintenance.

The effects of dry conditions

 Similar to heavy storms, droughts can also cause problems when excessive moisture in the oversaturated ground dries up. This can lead to soils shrinking, resulting in foundation movement and slab lifting due to the new conditions. Foundations that have been damaged due to settlement can cause cracks in walls, uneven floors, jammed or misaligned windows and doors, and skirting boards separating from walls. Puddles around the exterior of the building and leaking gutters can also result in saturation of the soil around the foundations, contributing to subsidence while slab lifting may result in cracked driveways and unlevel or sunken concrete floors

Remediating damaged foundations

Foundations and concrete slabs that have been affected by extreme weather and changing ground conditions can be repaired in many instances. However, it is essential to first identify the cause of the damage. A broken pipe or a blocked drainage system will require the appropriate tradesperson to fix the leaking prior to addressing the underlying weak foundation ground.

After assessing the extent of the problem and determining the area to be treated, Mainmark’s Teretek® resin injection technology can be applied to help re-level and re-support structures impacted by subsidence. When injected into the affected ground, the solution also increases ground bearing capacity and fills voids at a fraction of the cost and without the disruption of traditional underpinning.

With the impact of climate change increasingly noticeable in the region, property owners will need to be more vigilant about ground movement and know how to identify the signs of subsidence early to ensure professionals such as Mainmark are able to remediate the issue before the damage becomes too severe and too costly to address.

Theo HnatBy James O’Grady

James O’Grady is a Sales and Business Development Manager at Mainmark. He is a civil engineer with 25 years’ experience in structural engineering, construction materials and ground treatment.