8 Steps to Ensure Safe Structure Demolition Work
Published by jdelbo on
Despite its rigidity, a building usually has a finite lifespan. As soon as it reaches its 80th or 100th year, the structure may be unsuitable to be used safely. Most probably, the building fails safety standards. In this case, the facility will be earmarked for demolition unless a major conservation effort is planned. This stage in the lifetime of a structure is usually a necessary procedure to maximize space, which will benefit more people and businesses. Demolition work used to be a very hazardous task, and guidelines have been implemented over time to prevent accidents and minimize demolition costs associated with these accidents. Here are eight steps a contractor should take to achieve safer demolition work.
Planning and Permit for Demolition
Contractors should first carefully study the structure and surrounding areas before starting demolition work. The plan should also ensure to avoid unintended damage to surrounding structures. The engineer-in-charge will account for all details, especially the final plan of the sequence of operations. The plan is a major prerequisite for obtaining a demolition contract license or permit from the authorities and should be posted prominently at the site.
Precautions Before Demolition
The handling of explosives is heavily regulated. The first item to be considered is obtaining permission or approval from the authorities.
Place danger signs across the site to warn possible stragglers. All openings with access to the structure and affected areas should be kept barricaded, and place warning lights above these.
Coordinate the timing of the suspension of all utilities such as water, electricity, gas, steam, and other service lines surrounding the property to be demolished.
Post qualified security personnel responsible for keeping off unauthorized personnel from straying into danger zones.
Issue the appropriate personal protective equipment to all workers before starting demolition work.
Lastly, all fire safety precautions are in place on-site and in the surrounding areas.
Protection of the Public
Make sure all warning signages are in place prominently with proper lighting. Aside from blocking all access to possible affected areas, sidewalks and roads approaching and surrounding the site should be secured and adequately lighted.
Precautions during Demolition
First, all fragile items like glass should be removed from the site, and precautions for the windows in the surrounding buildings should be made. Take note that demolition using explosives will produce dust and should be controlled using appropriate means to protect the workers and the public. Even the stacking of demolition debris should be within the safe limits of the structural member and could require additional supports. Most importantly, adequate natural or artificial lighting and ventilation should be provided for all workers involved.
Management of Demolished Materials
First, no material shall be dropped from a height of more than 2 meters. The materials should be lowered either by containers, ropes, tackles, or chutes designed for the task. Chutes should be closed on all four sides and inclined at an angle of 45 degrees, with the top opening secured with guard rails. Holes on the floor may be allowed for dropping materials but only under extreme circumstances and adequately to prevent overloading the floor. Always plan to remove the debris at the earliest. Remove in stages to avoid being a nuisance to the public and overloading the site.
Safety Precaution during Mechanical Demolition
Demolition made with heavy equipment such as weight balls, power shovels requires the following additional precautions. Barricade the demolition area at least one and a half times the height of the wall. No workmen should be allowed to enter the building when demolition with the mechanical device is in progress. Position the mechanical device such that no debris could fall on it. Lastly, Make provisions such that the mechanical device will not damage nearby structures.
Other Safety Precautions
Make sure to avoid demolition work at nighttime, heavy rains, or storm, especially in an inhabited area. Ensure that red warning signals, working lights, and qualified security personnel are on hand to prevent accidents if nighttime demolition tasks can’t be avoided. Warning devices should be installed prominently across the site to warn workers (or the public) of any danger. Personal protective equipment should be worn at all times by workers involved on-site, like specialized gloves when demolishing RCC or steel structures and safety belts and ropes when working at higher levels. Consider the location of tool sheds and work boxes such that these should be safe from falling debris. Protection in the form of overhead covers and screens shall be provided to prevent the public and workers from falling debris.
First aid precautions should first require a qualified person to be on-site at all times to render first aid if required. The person qualified to do first aid work should maintain a list of personnel that can render first aid work in support. Enough first aid kits, including a stretcher, accessories, and cots should be provided at the site. A copy of all regulations and notices concerning accidents and injuries and telephone numbers of emergency services should be prominently displayed at the worksite. In the event of an accident, a complete report should be generated and forwarded to the concerned authorities.