As global temperatures continue to rise and heatwaves are becoming a common feature of UK summers, we explore how extreme temperatures can affect more than just our quality of sleep. Read on as Elliott Griffin, Senior Design Engineer, and Dave Bradshaw, Monitoring Manager, look into the impact on groundworks props, including how to mitigate thermal expansion and the value of monitoring systems in helping teams take proactive action.
It’s no secret that UK weather is becoming warmer and wetter, with extreme weather events – from heatwaves to winter storms and flooding – becoming more frequent and intense. Already, the summer of 2026 has broken records, with a new maximum temperature record for June and not one but two official heatwaves arriving in quick succession. Looking at the history books and the last decade has been warmer than any previous decade on record.*
As well as the sleepless nights, associated health risks and everyday tasks becoming more difficult, it’s also important to consider how extreme temperatures can affect temporary works equipment out on site – whether that’s props used to shore up a small trench run, a major city-centre basement excavation or retention of a building façade.
Already, temporary works engineers will account for expected temperature fluctuations in their design, referring to a 1.65 factor safety rating. In typical basement propping applications, engineers will allow for a 500kN variation in load derived from a 20-25ºC temperature range. Of course, as props increase in size, this too will increase. The temperature fluctuations can also depend on the time of year and how long the equipment will be on site for. For example, if the kit is only going to be in-situ during winter, this will carry different design considerations than a two-year long hire period across multiple seasons.
What happens in extreme heat?
When faced with consistently extreme temperatures, the design capacity of steel and mechanical props and struts can be affected. As we all know, metal will expand and contract as it heats and cools – a process called thermal expansion. As a prop is heated and the surrounding ground excavation (in the case of groundworks) or permanent structure limits its expansion, this can result in the prop loads increasing. In extreme cases, this can lead to a deflection or movement in the prop or structure, or alternatively the load being transferred elsewhere
Monitoring insight
So, the question faced by engineers across the UK as we look ahead to hotter summers is how we can manage the risk presented by these extreme temperatures? Of course, we can design with larger temperature fluctuations in mind – however, this can result in potentially over-engineering a temporary works scheme, at higher costs. There are also other factors to consider, such as in the case of deep ground excavations where you may have multiple levels of bracing, with the kit’s exposure to sunlight differing depending on the depth.
While employing intelligent monitoring solutions may not solve climate change, it can provide valuable insight into a site and its temporary works equipment, helping contractors to better manage risk and take proactive steps at an earlier stage.
Take LIVEpin monitoring as an example. A load-monitoring pin designed to fit seamlessly within our propping equipment, it measures the axial load applied to the system while simultaneously monitoring temperature. By establishing a baseline, site teams can then easily determine if the props are experiencing increased loads. While structural monitoring sensors can be installed to detect any movement, deflection or vibration in the ground or structure.
Used in conjunction, a careful balance between the two can provides continuous, accurate and real-time data, ensuring full visibility of changing site conditions. Systems can also issue alerts whenever pre-set thresholds are exceeded, enabling a prompt response and reactive action to be taken, such as covering the props or watering them down to limit the metal expansion. For example, a recent London basement propping job experienced 40ºC heat and teams were able to monitor the temperature’s impact on the temporary supports, with red alerts flagging the need to take action.
Mechanical vs hydraulic
In addition to highlighting the case for monitoring technologies, designing for heatwave conditions also emphasises the value of hydraulic versus traditional mechanical props. Installed onto bracing props and struts, hydraulic jacks offer safe and precise lifting and lowering for complex structural tasks. With integrated control and monitoring, they ensure accuracy, reduce risk and keep critical work moving efficiently.
Combined with monitoring insight, employing hydraulic jacks in conjunction with a bespoke temporary propping scheme can enable teams to automatically adjust the props or struts based on the live environmental conditions being experienced.
As well as a dedicated monitoring team, we have one of the largest fleets of hydraulic jacks in the UK. Combined with over 60 years’ of engineering experience, we have the expertise needed to ensure projects continued to be delivered safely and efficiently out on site, even as temperatures continue to rise.