Before starting demolition, Construction Management or persons in charge should adequately prepare for the task with regard to the health and safety of the workers and any occupants in adjacent spaces.
Overall building design and planning of the demolition job
Choose the most beneficial methods to be used for each stage of the work
Select the equipment necessary to properly complete the project
Confirm measures to be taken to perform the work safely
Identify and obtain personal protective equipment(PPE) appropriate for the task.
Demolition work involves many of the same hazards associated with construction. However, demolition also poses additional hazards such as:
* deviations from the structure’s original design
* approved or unapproved modifications that altered the original design,
* hazardous materials hidden within structural members
* unknown strengths or weaknesses of damaged materials
All personnel involved in a demolition project need to be fully aware of these types of hazards and the safety precautions available to control their impact. OSHA Standards should be reviewed and readily available.
A written engineering survey must be performed on each structure being considered for demolition to determine the condition of the framing, floors and walls, and to assess the possibility of an unplanned collapse of any portion of the structure.
Brace or shore walls and floors of structures which have been damaged and which employees must enter.
Inspect and maintain all stairs, passagewaysand ladders. Properly illuminate all stairways.
Shut off or cap all electric, gas, water, steam,sewer and other service lines outside the building or work area.. Notify appropriate utility companies. Temporarily relocate and protect any essential power, water, or other utilities.
Determine the types of hazardous chemicals,gases, explosives, and flammable materials which have been used in any pipes, tanks, or other equipment in the building or on the property. Test and purge the hazardous materials before starting work activities.
Survey for asbestos or other hazardous materials.
Guard wall openings to a height of 42 inches. Cover and secure floor openings with materials able to withstand the loads likely to be imposed.
Debris dropped through holes inthe floor without the use of chutes must be enclosed with barricades not lessthan 42 inches high and not less than 6 feet from edge of the opening above.
Floor openings used for material disposal must not be more than 25% of the total floor area.
Use enclosed chutes to drop materialto the ground. Post signs at each level of structures, warning o fthe hazard of falling materials.
Protect entrances to multi-story structures with sidewalk sheds orcanopies for a minimum of 8 feet. Canopies must be at least 2 feet wider than the structure entrance and be able to hold a load of 150lbs./sq. ft.
Storage of material and debris must not exceed the allowable floor load.
Removing Structure and Masonry Sections
Demolition of exterior walls and floors must begin at the top of the structure and proceed downward.
Masonry walls must NOT be permitted to fall on the floors of a building in masses that would exceed the safe carrying capacities of the floors.
No wall section, one story in height or higher,shall be permitted to stand alone without lateral bracing, unless such a wall was originally designed and constructed to stand without such support, and is safe enough to be self-supporting.
All walls must be left in a stable condition at the end of each work shift.
Structural or load-supporting members on any floor must not be cut or removed until all stories above such a floor have been removed.
In buildings of “skeleton-steel” construction,the steel framing may be left in place during the demolition of masonry.
Walkways or ladders must be provided to enable workers to safely reach or leave any scaffold or wall.
Walls, which serve as retaining walls to support earth or adjoining structures, must not be demolished until the supporting earth has been properly braced or until adjoining structures have been properly underpinned. Existing walls must not be used to retain debris, unless they are capable of supporting the imposed load.
Dismantle steel construction column length by column length, and tier by tier.
No workers shall be permitted in any area when using a crane’s demo ball or clam shell to remove debris. Only those workers necessary to perform such operations are to be permitted in this work area at any time. The configuration of the crane, load lines and ball must comply with applicable safety standards.
When pulling over walls or portions of walls, all steel members affected must have previouslybeen cut free.
All roof cornices or other ornamental stonework must be removed prior to pulling walls over.
Inspections by a competent person shall be provided thought demolition, to detect hazards resulting from weakened or deteriorated floors or walls. No employee shall be permitted to work where such hazards exist until they are corrected by shoring, bracing, or other effective means.
Reasons to recycle construction and demolition (C&D) wastes are simple but compelling:
1. Construction and demolition wastes are one of the largest waste streams in the country.
2. Almost all job site wastes are recyclable.
3. It costs less – usually much less – to recycle job site wastes than to throw them away.
4.The waste that’s generated during construction of a building is more than the occupants of that building are likely to throw out during one or two years of occupancy.
Almost All Job Site Wastes Are Recyclable. There is hardly a single waste material from a job site that cannot be recycled. Look at this chart
In almost all cases, the cost of recycling is lower than the cost of throwing materials away.This is a critical point. If recycling costs more than disposal, then there will always be a very good reason NOT to recycle. But if recycling is cost-competitive or less expensive than disposal, then recycling should be considered as part of every job.