Demolition is the act of tearing down existing buildings and structures. It can be as simple as removing a portion of a house for a renovation project or as complex as demolishing a multi-storey building. Over the years, demolition work has evolved from a mainly manual process to a heavily mechanical one. Some tasks still have to be done manually and now the majority of loss time injuries in demolition are from musculoskeletal disorders (MSDs). Simple and practical work methods to reduce the risk of overexertion have helped to lower the injury rates in this sector. However workers are still exposed to a variety of other occupational hazards including falling structures and materials, dust, asbestos, lead, hazardous noise levels, and potential of falls from heights.
Owners must determine if there is any asbestos that may be handled, disturbed or removed during the demolition or dismantling process. Please see Designated Substance -- Asbestos on Construction Projects and in Buildings and Repair Operations, O. Reg 278/05 to get a full description of the legal duties concerning working safely near asbestos. Owners must supply the demolition contractors with a designated substance report as well. The Occupational Health and Safety Act states that:
Duty of project owners
30. (1) Before beginning a project, the owner shall determine whether any designated substances are present at the project site and shall prepare a list of all designated substances that are present at the site.
It is a good idea to not only provide a list but to locate to the demolition contractor where the designated substances are located.
Remember there may also be local by-laws regulating demolition projects as well as other provincial regulations such as environmental rules that must be followed.
When a structure is so damaged that it becomes and hazard and endangers workers because of the potential for a partial or complete collapse, it must be braced and shored. Appropriate safeguards must be in place to prevent injuries of those near damaged structures or the demolition site.
Only workers who are working on the demolition, dismantling or moving of a structure can be in, on or near that structure. There must be barriers to prevent people from coming near or inside the remaining parts of a structure when the demotion or dismantling is stopped. Workers can only enter such a structure if it can support the worker and will not collapse.
Demolishing and dismantling of a building or structure
The listed rules below do NOT apply when any of the following are being used in the demolition process, a heavy weight suspended by cable from a crane or similar hoisting device, a power shovel, bulldozer or other vehicle, and the use of explosives.
Waste from a demolition project must be taken to a disposal area and reusable material to a storage area at least once a day and as often as is necessary to keep the site safe for workers and others. Please note that Ontario has a waste sorting and recycling regime covered in Ontario Regulations 102/94 and 103/92.
Garbage and recyclable materials must be lowered by chute into containers. Alternatively, these materials can be lowered by crane or hoist. Any materials falling freely during the demolition or dismantling must fall into designated enclosed areas. People must not have access to these designated areas.
O. Reg. 213/91
Part II GENERAL CONSTRUCTION
Section 35 Housekeeping
35. (1) Waste material and debris shall be removed to a disposal area and reusable material shall be removed to a storage area as often as is necessary to prevent a hazardous condition arising and, in any event, at least once daily.
(2) Rubbish, debris and other materials shall not be permitted to fall freely from one level to another but shall be lowered by a chute, in a container or by a crane or hoist.
(3) Despite subsection (2), rubbish, debris and other materials from demolition on a project may be permitted to fall or may be dropped into an enclosed designated area to which people do not have access.
(4) A chute,
(a) shall be adequately constructed and rigidly fastened in place;
(b) if it has a slope exceeding a gradient of one in one, shall be enclosed on its four sides;
(c) shall have a gate at the bottom end if one is necessary to control the flow of material; and
(d) shall discharge into a container or an enclosed area surrounded by barriers.
(5) The entrance to a chute,
(a) shall be constructed to prevent spilling over when rubbish, debris and other materials are being deposited into the chute;
(b) if it is at or below floor level, shall have a curb that is at least 100 millimetres high;
(c) shall not be more than 1.2 metres high;
(d) shall be kept closed when the chute is not in use; and
(e) shall be designed so that any person will be discouraged from entering it.
Section 212 Demolition and Damaged Structures
212. (1) If a structure is so damaged that a worker is likely to be endangered by its partial or complete collapse,
(a) the structure shall be braced and shored; and
(b) safeguards appropriate in the circumstances shall be provided to prevent injury to a worker.
(2) Safeguards shall be installed progressively from a safe area towards the hazard so that the workers installing the safeguards are not endangered.
213. (1) Only a worker who is directly engaged in the demolition, dismantling or moving of a building or structure shall be in, on or near it.
(2) If the demolition or dismantling of a building or structure is discontinued, barriers shall be erected to prevent access by people to the remaining part of the building or structure.
(3) A worker shall enter only the part of a building or structure being demolished that will safely support the worker.
214. (1) No building or structure shall be demolished, dismantled or moved until this section is complied with.
(2) Precautions shall be taken to prevent injury to a person on or near the project or the adjoining property that may result from the demolition, dismantling or moving of a building or structure.
(3) All gas, electrical and other services that may endanger persons who have access to a building or structure shall be shut off and disconnected before, and shall remain shut off and disconnected during, the demolition, dismantling or moving of the building or structure.
(4) All toxic, flammable or explosive substances shall be removed from a building or structure that is to be demolished, dismantled or moved.
215. (1) Sections 216, 217, 218 and 220 do not apply with respect to a building or structure that is being demolished by,
(a) a heavy weight suspended by cable from a crane or similar hoisting device;
(b) a power shovel, bulldozer or other vehicle;
(c) the use of explosives; or
(d) a combination of methods described in clauses (a) to (c).
(2) The controls of a mechanical device used to demolish a building or structure shall be operated from a location that is as remote as is practicable from the building or structure.
(3) If a swinging weight is used to demolish a building or structure, the supporting cable of the weight shall be short enough or shall be so restrained that the weight does not swing against another building or structure.
216. (1) Demolition and dismantling of a building or structure shall proceed systematically and continuously from the highest to the lowest point unless a worker is endangered by this procedure.
(2) Despite subsection (1), the skeleton structural frame in a skeleton structural frame building may be left in place during the demolition or dismantling of the masonry if the masonry and any loose material are removed from the frame systematically and continuously from the highest to the lowest point.
(3) The work above a tier or floor of a building or structure shall be completed before the support of the tier or floor is affected by demolition or dismantling operations.
217. No exterior wall of a building or structure shall be demolished until all glass is removed from windows, doors, interior partitions and components containing glass or is protected to prevent the glass from breaking during the demolition.
218. (1) Masonry walls of a building or structure being demolished or dismantled shall be removed in reasonably level courses.
(2) No materials in a masonry wall of a building or structure being demolished or dismantled shall be loosened or permitted to fall in masses that are likely to endanger,
(a) a person; or
(b) the structural stability of a scaffold or of a floor or other support of the building or structure.
219. No worker shall stand on top of a wall, pier or chimney to remove material from it unless flooring, scaffolding or staging is provided on all sides of it not more than 2.4 metres below the place where the worker is working.
220. No truss, girder or other structural member of a building or structure being demolished or dismantled shall be disconnected until,
(a) it is relieved of all loads other than its own weight; and
(b) it has temporary support.
221. (1) A basement, cellar or excavation left after a building or structure is demolished, dismantled or moved,
(a) shall be backfilled to grade level; or
(b) shall have fencing along its open sides.
(2) Subsection (1) does not apply to a basement or cellar that is enclosed by a roof, floor or other solid covering if all openings in the roof, floor or covering are covered with securely fastened planks.
221.1 - 221.19 Repealed. [O. Reg. 96/11, s. 1]
[O. Reg. 632/05, s. 3; 96/11, s. 1]