The effects of a heatwave on construction workers

As we’ve been dealing with an ongoing heat wave in the UK, we thought it was important to address some of the issues that might face the construction workforce.

Heatwaves and droughts can disrupt the industry by causing worker fatigue and health risks, altering how materials cure or set, destabilising dry and shrinking soils, and triggering water restrictions that limit site operations, ultimately leading to widespread project delays and potential rising costs.

Worker Health and Safety

It’s not just the physical work that becomes increasingly hard due to the heat, but also the added effects of excessive heat on the workers themselves.

This can lead to;
• Heat stress: High temperatures increase the risk of dehydration, heat exhaustion, and heatstroke, making outdoor labourers significantly more vulnerable to illnesses.

• Fatigue and errors: The heat can cause physical fatigue and lower concentration, raising the likelihood of site accidents, slips, or equipment misuse.

• Adjusted schedules: Crews often have to start significantly earlier, take more frequent mandatory rest breaks, or stop outdoor tasks entirely during peak afternoon heat.

There is also the issue of material performance and quality that can be impacted by temperature:

• Fast curing and drying: Concrete can cure too quickly in the heat, which can compromise its structural strength, while paints, adhesives, and sealants dry or set faster than intended.

• Softened surfaces: Asphalt can become overly soft during extreme heat, making paving and heavy vehicle movement difficult.

• Equipment strain: Machinery and vehicles face a higher rate of overheating, which can lead to mechanical failures and demands for extra maintenance.

Ground conditions and drought Impacts;
• Soil shrinkage: Prolonged dry spells cause cohesive soils like clay to shrink, which can destabilise open excavations and threaten nearby structures or shallow foundations.

• Dust and environmental control: Dry earth increases airborne dust, forcing sites to spend more time and resources on water-intensive dust suppression.

• Water scarcity and restrictions: Drought conditions frequently lead to local hosepipe bans or strict limits on pulling water from municipal supplies for construction use.

These can cause project timelines to change adding extra commercial risks;
• Schedule slippage: Reduced daily working hours and material adjustments accumulate into weeks of project delays.

• Contractual disputes: Standard industry contracts are often ill-equipped for heat-related disruptions, resulting in conflicts over who covers the financial burden of weather delays.