Demolition contractors carrying out the demolition of buildings, including ‘system’ buildings must take into consideration the way in which these buildings were constructed when planning a safe method for their demolition.
Demolition of buildings, including prefabricated ‘system’ buildings, in the incorrect sequence can result in the potential for movement and sudden unplanned collapse of parts of the building.
In the case of prefabricated ‘system’ buildings, the development of serious structural weakness in the rigidity of the steel frame can result in the premature collapse of the individual pre-cast concrete floor units.
In developing a safe system of work for the demolition of such structures it is essential that consideration, involving a structural engineer, is given to the way in which the structure was designed and constructed. This may involve such issues as:
- obtain complete knowledge of the building, which will likely include; obtaining the original design drawings for the building, contacting the building designers if possible, previous collapse history relating to the form of the structure, e.g. large panel precast concrete construction and lift-slab concrete structures
- carry out inspection surveys and assessments of the building, including a detailed structural assessment to identify any structural hazards
- develop a safe system of work, set out in a written method statement, for the demolition of the building. This should identify in detail the sequence of the operation, including any pre-weakening and the provision for temporary supports for structural stability, where necessary, designed by a competent engineer
- ensure the demolition is carried out by competent employees under the supervision of an experienced and competent supervisor who ensures that the method statement is followed
- if the demolition of the structure identifies unforeseen issues, the demolition should stop until these matters have been reviewed with changes made to the method statement, if required. Any changes should be recorded
This list is not exhaustive and does not take into account other issues such as the potential for the presence of asbestos.
Legal Requirements applicable to demolition
Management in Construction (Jersey) Regulations 2016
Health & Safety at Work (Jersey) Law, 1989
British Standard 6187:2011 Code of Practice for full and partial demolition