Construction industry is a very risky and hazard prone industry and when it comes to demolition, the risk and hazards intensifies. While in the construction industry, the structure is being setup, so the strengths and limitations of the structures are known. However, coming to the demolition work, it is some old structure and a little is known about the structure. Therefore, a lot of preparation has to be done when it comes to pursue a demolition or a cleanup tasks. Proper survey and preparations has to be done for planning a demolition task. Risk has to calculate judiciously and necessary machinery and safety procedures should be arranged.
Many factors make the demolition work risky and hazardous. Sometimes changes occur which are neither documented nor approved and risk is there of surprise elements. Some of the prominent factors include deviation of structure from original design, hidden materials in structures and unknown load bearing properties of the structure.
Preliminary preparations for demolition
Demolition work involves presence of much unexpected risks. Hence, adequate preparation should be ensured before going for the demolition. Some recommended OSHA preliminary tasks before going for a demolition be as follows:
- Written engineering survey has to carry by experienced and competent persons to identify and evaluate the risks associated with the structures. Any possibility of unplanned collapse of the structures should be taken care of.
- All the stairways and essential parts of the workplace must be illuminated properly and weak floors and walls should be braced so that they do not collapse unprecedentedly.
- All the services like electricity, gas, steam, sewer etc. should be either shut down or capped. Concerned authorities should be notified in due time regarding the same.
- Assessment should be done for hazardous chemicals, flammable materials, gases, and explosives, which may have been used in some pipes or containers. Such hazards should be taken care of.
- Floor openings that are used for disposal of materials should not be more than 25% of the total floor area. Any guard wall openings up to a height of 42 inches should be covered with suitable material that can bear the weight of the load put on it.
- Entrances of a multistory structure should be protected with sidewalk sheds or canopies for a minimum of 8 feet. Canopies protecting the structure entrances should be 2 feet wider than the structure entrance and should be able to bear a load of 150 lbs/sq ft.
- Signs must be posted in appropriate places communicating the danger of the falling materials and the protection to be used.