Demolition activity is a major site base activity which takes place in fairly all construction sites. Demolition involves the process of tearing down, pulling down, knocking down, flattening, leveling or bulldozing an existing structure.
The process of demolition could be brought about by development, upgrading, etc. Since demolition is one activity which is inextricably linked with construction projects, we have to define measures to ensure that the process is carried out successfully.
According to OSHA, Demolition is the dismantling, razing, destroying or wrecking of any building or structure or any part thereof. Demolition work involves many of the hazards associated with construction. However, demolition involves additional hazards due to unknown factors which makes demolition work particularly dangerous. These may include:
- Changes from the structure’s design introduced during construction;
- Approved or unapproved modifications that altered the original design;
- Materials hidden within structural members, such as lead, asbestos, silica, and other chemicals or heavy metals requiring special material handling;
- Unknown strengths or weaknesses of construction materials, such as post-tensioned concrete;
- Hazards created by the demolition methods used.
This is why this article after explaining “Demolition meaning”, will also highlight the demolition risk assessment, hazards of the breaking down process and also safety tips you could follow while carrying out demolition activity.
To ensure the safe completion of a demolition activity, two main approaches are mostly adopted:
- Piece meal: Here the structure is being taken down in bits till it is completely flattened.
- Planned collapse: In this pattern of demolition, the supporting components of the structure are always targeted. When the supporting structures are being removed, the building will collapsed on its own.
Hazards Associated With Demolition Activity
Some hazards associated with demolition activity are;
- Uncontrolled collapse
- Falls from height
- Asbestos and other hazardous substances
- Hazardous materials
- Falling debris
- Falling objects
- Injury from falling materials
- Risks from connected services
- Safety considerations during demolition
- Traffic management
All these hazards poses different level of risk which could range from low risk to very high risk, on this note, demolition activity must be carried out safety which must begin with an in-depth risk assessment.
Demolition Risk Assessment
Due to the numerous risk involved with demolition activity, it is always advisable for proper risk assessment to be carried out before the commencement of the job. This risk assessment will help identify potential hazards and analyze what could happen if a hazard occurs. Some of the risk involve in demolition process are: Fall from height, falling objects, uncontrolled collapse, connected services, exposure to hazardous materials, traffic issues, noise, vibration, fire & explosion, etc.
There is no set format or template for creating your own demolition risk assessment set out by the government or within construction regulations.
If you intend to create your own risk assessment, you should include key areas:
- Identify each action and the dangers associated with it
- Determine its risk level
- State the controls that will be put in place
- Identify who will put controls in place and monitor conformity
Demolition Safety Precautions
Here are some safety precautions to be taken when carrying out demolition activity;
- Work should be carried out based on the result of the risk assessment carried out for the demolition activity.
- Only trained operators and workers should be used for the job
- Known risk should be communicated to all members of the team to ensure collective safety.
- The best demolition strategy should be adopted, i.e, Piece meal or planned collapse.
- The history of the structure should be gotten, which will help in identifying some inherent risk which may not be obvious. Like presence of Asbestos, buried services, etc.
- Safe access to and egress from the demolished structure should be provided.
- Adequate segregation should be done to protect third-party intrusion and prevent harm to the public.
- Adequate PPE should be provided and enforced through out the duration of the activity. If need be, the workers should be trained on proper use of PPE before the commencement of the task.
- To prevent immature collapse, some areas may need to be shored.
- Full inspection of the structure should be carried out before the commencement of the demolition activity.
- Adequate job design and procedures should be adopted. For example to protect workers from excessive exposure to vibration, the duration of exposure should be reduced by carrying out the job on shift basis.
- Ensure that the right machineries are selected for the job.
Base on our topic “Demolition meaning – Demolition risk assessment and Safety precautions“; We have successfully highlighted 12 concrete safety precaution for demolition activity. All of these may not be applicable in all demolition activity always, but anytime demolition activity is to be carried out, risk assessment should be carried out by a competent person, and relevant safety precautions adopted to ensure the successful completion of the task.