A lot of people get hurt and killed on construction sites every year. The reality is that there are few hazards that only occur on construction sites but there are often more of them present at any time and keeping control can be difficult. Also, the way buildings and other structures are designed and constructed needs careful consideration to ensure they can be built, used, maintained and even demolished safely.
Parties involved in construction
There are a number of parties involved in construction. All have a part to play in safety, and this requires them to cooperate. They include
- The client – the person who has commissioned the work;
- Designers – people who influence what is built;
- Principle contractor;
Because of the number of parties, someone will typically need to take responsibility for co-ordinating the construction.
Part of the problem with the construction industry is that safety is not always adequately considered when buildings and other structures are designed. This is a fundamental flaw that can result in injury to construction workers, and have an impact on future users and maintainers. To avoid this it is important that building designers
- Eliminate hazards where possible;
- Reduce risks from those hazards that cannot be eliminated (e.g. specify designs to reduce the need/frequency for hazardous tasks during construction and subsequent use and maintenance);
- Provide information on any significant residual risks (e.g. if a set sequence of assembly or demolition is required to maintain structural stability).
In order to achieve the above a competent designer will need knowledge and experience of the construction process. In this context designers include anyone who specifies what is built or how it is built including architects, consulting engineers, quantity surveyors, building service engineers, temporary works engineers.
Considerations at the pre-tender stage of a project
Making provision for safety can be expensive, and if not properly budgeted for it may not happen. Because of the competitive nature of tendering for construction work, it is important that principle contractors have full information about hazards and risks at the time of preparing their bid. That way they can prepare a safe schedule of work and therefore specify a realistic price.
Health and safety during construction
Construction activity is inherently hazardous and so good health and safety planning is essential. Plans should be developed that cover:
- The arrangements for the management of health and safety of the construction work;
- The monitoring systems for checking that the health and safety plan is being followed;
- Health and safety risks to those at work, and others, arising from the construction work, and from other work in premises where construction work may be carried out.
People get hurt on construction sites because:
- They fall off things;
- They fall into things (e.g. holes);
- They trip over things;
- Things are dropped on them;
- They are squashed by moving equipment and vehicles;
- They are exposed to hazardous substances (especially asbestos, dust and solvents in adhesives and paints);
- They come into contact with electricity;
- They get hurt during manual handling
The challenge is that because of the nature of activity, the situation is very fluid and changes all the time. Also, there can be many parties involved in hazardous work at any time. This is why managing safety on construction sites is often a challenge.
Excavations create a number of hazards closely related to working at height. In particular people can fall into the excavation and things can be dropped on people who are in the hole. There is no specific depth at which an excavation is considered to be dangerous, remembering that someone bending over or kneeling down in a shallow hole could be seriously hurt if it collapses.
Also, excavations can become confined spaces, there is the potential for sides to cave in and for contact to be made with underground hazards including buried services and contaminated soil.
Precautions to stop excavations caving in include angling the sides instead of making them vertical, making sure spoil from digging the excavation is not left at the side and providing support using timber, sheeting or propriety systems.
The potential for buried services should be identified before starting the excavation. Where this risk is not zero precautions such as detectors/locators and digging of test trenches should be used.
A competent person must inspect excavations:
- At the start of each shift before work begins;
- After any event likely to have affected the strength or stability of the excavation;
- After any accidental fall of rock, earth or other material.
A written report should be made after most inspections.
Of course there are also hazards associated with the method used to create the excavation. Doing it by hand creates manual handling issues whilst alternative methods usually involve the use of vehicles.
Confined space entry
A confined space is any space of an enclosed nature where there is a risk of death or serious injury from hazardous substances or dangerous conditions. They include storage tanks, silos and vessels, enclosed drains and sewers, open-topped chambers, ductwork, poorly ventilated rooms and excavations.
Potential hazards include lack of oxygen, hazardous substances either from the previous contents of the space or the work being carried out (e.g. fumes), flammable atmospheres and hot working conditions. Also, it must be recognised that rescuing someone from a confined space can be difficult due to poor access. Confined space entry must be carefully planned and controlled.
Factors to consider when planning confined space entry include:
- Is it necessary?
- Are the people suitable for the task (competence and health)?
- Isolating the space from all potential sources of hazard;
- Cleaning the space;
- Ensuring a large enough entry;
- Providing ventilation;
- Testing air quality;
- Provision of special tools;
- Use of breathing apparatus if there is a risk of the air becoming unbreathable (but it must not be used instead of isolation, cleaning etc.);
- Emergency plan;
- Rescue equipment;
The Confined Spaces Regulations 1997 apply.
Reference – ‘Safe work in confined spaces’ available free at http://www.hse.gov.uk/pubns/indg258.pdf
Reference – Approved Code of Practice L101 ‘Safe work in confined spaces’ available free at http://www.hse.gov.uk/pubns/priced/l101.pdf
Work on or near water
Whenever someone is working near water or on water (sea, river, lake, pond) the risk of drowning must be considered. Obviously it is most important that the likelihood of them falling in the water is minimised by providing barriers, working platforms, harness and lines etc. However, where the risk of falling into water cannot be eliminated it is important to consider the provision of buoyancy aids and rescue plans. Cheap and simple buoyancy aids tend to be bulky, and so are generally not suitable for anyone doing any work. More practical buoyancy aids are likely to have a self-inflating mechanism, and it is essential that these are properly maintained and checked before use. It is also important that people know how to use them.
Drowning is not the only hazard of falling into water. Hypothermia can set in if someone is in cold water for some time (within 30 minutes). Also, there are some animal borne diseases that are commonly found near water (e.g. leptospirosis causing Weils disease).
Reference – ‘Personal buoyancy equipment on inland and inshore waters’ available free at http://www.hse.gov.uk/pubns/ais1.pdf
CDM regulations apply to most common building, civil engineering and engineering construction work. They require clients of construction work to make reasonable arrangements for managing projects (including the allocation of sufficient time and other resources) so that:
1. Risks to health and safety are managed by applying general principles of prevention,
2. The right people and organisations are appointed at the right time;
3. Everyone has the information, instruction, training and supervision they need to carry out their jobs in a way that secure s health and safety
4. Dutyholders cooperate and communicate with each other and co-ordinate their work
5. Workers are consulted and engaged with to promote and develop effective measures to secure health, safety and welfare
The regulations identify the following duty holders and specify their role and main duties:
- Domestic clients (in the scope of the regulations but duties are normally transferred to the contractor to principal contractor);
- Principle designers;
- Principal contactors;
Appointments need to be made in a timely manner so that there is time to develop suitable health and safety plans before construction begins. Everyone involved in the project must seek the co-operation of, and co-operate with others working on the project. Also, any person working under the control of another person has to report anything they are aware that is likely to endanger the health or safety of themselves or others.
Every person involved in design, planning and preparation of a project must take account of the general principles of prevention of accidents and ill health.
For the purposes of these Regulations, a project is notifiable to the Health and Safety Executive if it is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point in the project; or exceed 500 person days.
A construction phase plan must be developed during the pre-construction phase and before setting up the construction site. It must set out health and safety arrangements and site rules.
Where a project involves more than one contractor a health and safety file must also be prepared containing relavant information about the project. It should include:
- A brief description of the work carried out;
- Any hazards that have not been eliminated through the design and
- Construction processes, and how they have been addressed (eg surveys or other information concerning asbestos or contaminated land);
- Key structural principles (eg bracing, sources of substantial stored energy including pre- or post-tensioned members) and safe working loads for floors and roofs;
- Hazardous materials used (eg lead paints and special coatings);
- Information regarding the removal or dismantling of installed plant and equipment (eg any special arrangements for lifting such equipment);
- Health and safety information about equipment provided for cleaning or maintaining the structure;
- The nature, location and markings of significant services, including underground cables; gas supply equipment; fire-fighting services etc;
- Information and as-built drawings of the building, its plant and equipment (eg the means of safe access to and from service voids and fire doors).
The client must be given the safety file at the end of the project and take reasonable steps to ensure that it is kept available for inspection by those considering future construction work.
Reference – The regulations are available free at http://www.legislation.gov.uk/uksi/2015/51/pdfs/uksi_20150051_en.pdf
Reference – ‘Managing health and safety in construction’ available free at https://www.hse.gov.uk/pUbns/priced/l153.pdf
Demolition is essentially the opposite of construction, and similar approaches are required to manage the risks. Specific issues to be aware of include:
- Exposure of people to hazardous materials within the building or structure being demolished (e.g. asbestos);
- Unpredictability of where material will fall – requiring adequate exclusion zones;
- Potential to impact on members of the public;
- Hazards from the method of demolition used (especially if using explosives).
As with construction, good planning is essential. The CDM regulations apply to demolition.