THE INFLUENCE OF WEATHER ON CONSTRUCTION WORK AND ELECTRICAL CONTRACTORS’ OBLIGATIONS

By Uwe Putlitz

Uwe Putlitz

Working on construction sites is inherently a risky business. Execution of the works is governed by the Occupational Health and Safety Act 1993 and the Construction Regulations 2014 (revised 2017), which are generally complied with by the larger contractors but less so by SMME contractors, who often have limited cash resources and are not necessarily using the correct equipment. Whilst comprehensive and practical, the regulations are less specific when it comes to dealing with the effects of weather.

Subcontractors, in particular electrical and plumbing subcontractors, often have to provide temporary services for use by all other contractors on site. Such services must be repositioned as work progresses on site within normal safety specifications.  

Responsibility of designers

The Act requires designers to apply their mind at the project concept phase as to how the works are to be executed – and while novel construction processes may be required, that these remain practical.

Failure to comply

The Act also stipulates that fines may be imposed on companies that fail to comply and repeat offenders could face imprisonment. A Department of Labour inspector may issue a notice to comply or close down any site or suspend any operation not in compliance with the approved Health and Safety plan and the Construction Regulations.

It is therefore prudent for subcontractors to consider the following information when tendering or when working on sites.

Climatic conditions

Historic climatic conditions should be considered when assessing the possible execution risks that may be encountered on a construction site in a particular location. As part of the site establishment, the contractor should provide equipment to record abnormally high or low or temperatures; excessive rainfall that may lead to flooding – including the quantum of rain over a 24 hour period; extreme wind speed or gusts; and unseasonal snow or thunderstorms and the equipment should also record the time and duration of such occurrences.

This equipment should be regarded as essential because abnormal climatic events may entitle a (sub)contractor to a revision of the date for practical completion and possible compensation should unspecified remedial actions be required. Without such equipment, the subcontractor would not be able to report with any degree of accuracy whether work on site could proceed safely during or after such an event. Accurate data will allow the subcontractor to motivate preventative or other actions that are necessary to protect personnel and the works as a whole in order to justify an extension of time claim and additional costs, regardless of the Standard form Contract used.

Construction equipment

Where extreme weather conditions are expected, the positioning and use of construction equipment will require particular attention to ensure the safety of trafficable surfaces, the integrity of guardrails, the erection of suspended platforms or scaffolding and/or hoists, bulk mixing plant and the use of tower cranes. Such equipment must be positioned rigidly and restrained in itself or as part of the structure to withstand sudden wind gusts and/or torrential rain. Should such adverse conditions arise, the site must be closed and evacuated in an orderly rehearsed manner.

During regular tool box talks, the construction manager, supervisor or site agent must instil a culture of safe working procedures so that, in the event of an emergency, all employees’ actions are ‘automatic’ to avoid panic and to prevent personal injury and loss or damage to the permanent works or the temporary works.

Should any weather-related event occur, or any other unforeseen event (for example, local community unrest) the construction manager must be prepared to react speedily and appropriately to warn the personnel on site by activating a siren.

Personal Protective Equipment

The contractor is obliged to provide personal protective equipment and clothing for all personnel to suit anticipated working conditions on the site, for example, safety signage and barriers, the review of and the training in standard procedures for firefighting, emergency escape routes from excavations or the incomplete structure, and fall protection equipment when working at heights.

Temperature

All personnel must wear seasonally appropriate clothing and personal protective equipment. Exposure to very low temperatures – even for short periods – may cause hyperthermia or frostbite while very high temperatures (40 °C and above) may cause heat stroke. Where such conditions are likely, restricted working hours may have to be introduced such as working at night to avoid the heat of the day or the provision of industrial heaters in during cold spells.

High temperatures on site may make it impossible to operate some hand-tools or to handle metal materials for installation without wearing of the appropriate special gloves.

When placing concrete, unless a special mix is used, the structural integrity of an element may be compromised when temperatures fall to below 5 °C or exceed 35 °C. In such conditions, either heating or insulation, or cooling with ice may be required. If fresh concrete is exposed to sudden temperature changes, including wind gusts, thermal cracking may result, and impair structural integrity.

Wind

Wind speed in excess of 40 km/h makes it unsafe to work on scaffolding, on a roof, and operate a crane. Most current generation tower cranes have monitoring equipment installed to automatically record the date, time, and wind speed and direction. During high winds, objects lifted by crane may be blown against the structure and result in damage to the object and the structure, and personnel may be injured by falling debris that has been dislodged from hooks or slings.

Special precautions must be taken when handling ‘hot’ metal roof sheeting in high winds as there is a possibility that roof sheeting can ‘twist’ or be blown away before fixing can occur.

Electric storms

When lightning flashes are followed by thunder within 30 seconds, all outdoor activities must be suspended, and employees must be warned to avoid hilltops, open water, trees or isolated structures.

Flooding

Rain in excess of about 40 mm per hour is likely to cause flooding and other damage particularly to excavations and foundations that may require extensive repairs. Depending on the nature of the site it may be appropriate to prepare a construction site to facilitate drainage of sudden flooding.

About the author: Uwe Putlitz Uwe Putlitz  Pr Arch, Pr CPM, FRICS, was born in Johannesburg, qualified as an Architect at the University of the Witwatersrand and subsequently awarded the first M Sc (Building). He practiced as an Architect and/or as a Project Manager for various firms and as managing member of Building Strategy Network until 2000 when he was appointed as CEO of the Joint Building Contacts Committee until his retirement in 2019. Uwe is a visiting lecturer at the University of the Witwatersrand, and the Royal Institution of Chartered Surveyors (RICS), regularly contributing articles to various industry journals about ‘dispute avoidance’ when using Standard-form Contracts.  
uwe@buildstrat.co.za  

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