Weather is a critical factor in construction design, planning and execution has among the most varied and far-reaching effects on project outcome.
It is one of the most frequent and harmful causes of project delays and weather claims are a frequent cause of dispute between contractors and owners. These disputes can escalate into legal action, extended delays and further economic losses.
Just one serious weather event leading to a day of lost work on a $200M project could cost a construction company $250 K directly from its profit. (1)
The key advice here falls into three categories: planning, notices and record-keeping.
These could equally be referred to as before, during and after.
Programmes should make allowances for weather conditions. This requires good risk management and risk knowledge. Extensive, local weather data helps bidding teams and construction site managers plan more effectively, accurately and profitably by:
It is essential that weather forecasts and actual conditions are continuously monitored. Contracts are likely to require the contractor to give notices to the employer if adverse weather (or anything else) is likely to cause a delay to project completion. The contractor should ensure that the notices are given in accordance with the timing and details required, to the people specified under the contract. Detailed weather forecast data through out the contract can aid in:
Weather claims are a frequent cause of disputes, often escalating to legal action and extended delays. Construction contracts have penalties called liquidated damages, which are paid by the contractor to the client when the deadline is missed. However, if a project is delayed by extreme or unforeseeable weather, the contractor can request an Extension of Time (EoT) to be waived from financial penalties.
In terms of building contracts, weather events are usually classified as:
Taking this last point, in some cases delays can be so sizable and excessive due to adverse weather that ‘force majeure’ may be indicated as the cause of the delay. Force majeure, sometimes referred to as the Act of God clause, it is a failure to uphold a contract due to unavoidable or uncontrollable events like extreme weather events. (3)
However, Foreseeable vs Unforeseeable is not so self-evident. Most construction contracts use the term 'exceptionally adverse' weather conditions (or similar), but not all will accurately define it.
For example, NEC engineering contract refers in clause 60.1(13) to weather events which are shown to occur on average 'less frequently than once in ten years'.
Similarly, previous case law for JCT contracts often refers to 10 years of previous meteorological records for sites as the frame of reference within which to argue. (4)
Construction projects can be affected by many weather conditions, but the wind requires special attention. It can change rapidly and without warning, and gusts can lift materials and even equipment. In extreme cases, strong wind may cause the collapse of cranes or structures in progress, but even gusts of 30knots / 15.4m/s / 34.5mph or more can delay activities like concrete pouring, form-works, scaffolding, steelworks and outdoor painting.
Using historical data as the base point, if a contractor has access to detailed and accurate on-site records they can demonstrate that X hours of wind above this level in a certain month is “exceptional”, allowing the contractor to evidence a claim for extension of time.
Solely relying on a Met Office weather warning for weather conditions which are likely to cause delay (such as snow or wind) in the relevant area will not be sufficient to protect against the weather. In terms of claims, weather forecasts don’t provide enough proof by themselves to justify a weather claim. Consider that a weather forecast is a prediction, not measured data. Without actual measurements, a contractor cannot prove that weather conditions at the project were unsafe for construction work.
However, even forecasts and readings provided by local weather stations are not fully accurate. In terms of wind data in particular, ground level measurements at the construction site do not reflect actual conditions for tall structures and cranes. A weather station on a 10m pole does not reflect wind conditions for a 250m tower crane. Wind speeds increase with altitude, as the wind is disrupted by obstacles at ground level.
To justify a suspension of lifting activities, there is no better evidence than measuring the wind directly at the crane. WINDCRANE wind monitoring provides accurate wind data specific to the location and height for construction cranes.
WINDCRANE enables planning the optimal time for crane lifting and site operations using SPECIFIC FORECASTING from wind speeds that are supported by the exact localised wind data from within the crane at the exact operating height, and not a prediction from a nearby weather station.
WINDCRANE provides LIVE WIND SPEED RISK OVERVIEW, supporting the safety of your personnel and equipment by reducing unnecessary risks with LIVE wind speed data and alert notifications.
WINDCRANE provides DOWNTIME WIND REPORTS using accurate HISTORICAL measurements from the exact crane height. Reduce weather disputes by recording and demonstrating accurate WIND SPEED DATA.
In summary; site specific weather forecasting, continuous monitoring and recording of weather data is essential FROM PLANNING RIGHT THROUGH TO PROJECT COMPLETION.
WINDCRANE provides historic, live and recorded wind data and reports specific to crane site and height: Solid evidence to back claims for delays due to ‘unforeseen’ and ‘exceptional’ weather conditions.
Visit our FAQ for more information or contact us to discuss your wind speed requirements.
(1) Weather assessment solutions in construction
(2) Construction Management and Economics Journal
(3) Extreme weather the construction industry costs
(4) Construction contracts adverse weather