Demolition of buildings requires planning and preparation. Review the building or structure before work starts.
Anyone planning a building or construction task which includes demolition is obliged to formulate the project such that demolition can take place properly. The planner must advise the developer of necessary surveys, e.g. surveying for asbestos and lead in the building.
In many instances, demolition of buildings or major partial demolitions will have to be regarded as particularly hazardous work. This means that the developer on building sites where there is more than one employer at the same time will have to prepare a Health and Safety Plan for this work.
The employer must assess the work, specifying arrangements so that the work can be done properly from the point of view of health and safety. This assessment must be presented in writing.
The building or structure must be assessed with regard to the following:
- Are materials, building elements or debris hazardous to health present, e.g.:
- asbestos, PCBs, chlorinated paraffins, paint containing heavy metals (lead, zinc and mercury)?
- syringes/needles used for drugs, batteries or faecal matter (waste) from humans and animals?
- has the building been used – for example – for storage of mercury-dressed grain or feeds, or has it been severely damaged by moisture (biologically active dust)?
- Could the ground be contaminated?
- Could selective demolition weaken the stability of the structure?
- During demolition, should you pay particular attention to the surroundings, e.g. in the event of vibration, noise or dust?
- Is there any electricity, gas, water or other installations requiring special handling?
- Can you carry out the work in a different way which is less stressful for the working environment, e.g. blasting or cutting in place of concrete cutting?
- Do you have to remove the insulation granules prior to demolition so as to prevent problems with dust?
- Is there any pre-stressed concrete with wires?
If the assessment shows that there is e.g. asbestos, PCBs, mineral wool, paint containing heavy metals (lead, zinc and mercury) or faecal waste, this must be removed before you commence the actual demolition work.
Demolition work must be managed and monitored by an experienced person who can assess whether the building elements remaining are stable. The people carrying out the actual demolition work must also include people with experience.
Minors under 18 may only work with demolition if this is taking place in connection with training which aims to give them skills (e.g. as apprentices), and if they receive the proper instruction.
Checklist prior to demolition
Before demolition work commences, the contractor must ensure that:
- Electrical cables, gas pipes and similar are disconnected (by an authorised installer).
- The work area is cordoned off and that temporary reinforcement and securing arrangements are installed on an ongoing basis.
- The necessary reinforcement materials are available.
- Doors and windows are covered so that no materials fall out.
- Appoint someone to stand guard, if necessary.
- Transport and access routes are safeguarded by means of covers, where necessary.
- The work is carried out in the sequence specified in the tender documentation and schedule.
- The necessary signs are put up.
- Non load-bearing structures are secured.
- The necessary scaffolding and other technical aids are put in place.
- Employees have the necessary personal protective equipment available to them and do actually use it, e.g. helmets and protective footwear.
- Waste is positioned and disposed of as per the tender documentation.
- Machinery and systems used are cleaned and prepared appropriately in terms of health and safety before and after use. For example, if specific decisions are made on items left behind; technical aids, machinery, pressure vessels and material containers, hoists, equipment with radiation sources and suchlike.
Reduce the amount of dust in the air by means of extraction, cleaning with a suitable vacuum cleaner and spraying with water. If necessary, wear dust masks, goggles and dust-repellent workwear.
As a dust mask, you can wear a half mask fitted with a class P2 dust filter or – even better – a full mask. It is a good idea to use a coarse dust filter to protect the fine dust filter.
Traditional single-use masks will not normally be suitable for demolition and similar very dusty work.
As demolition work often creates a lot of dust, even if attempts are made to restrict this, it will be necessary in many situations to use respiratory protection throughout the entire work period. Here, it will not be possible to use general filtered respiratory protection as this may only be used for three hours over the course of an entire working day. Instead, you could use a suitable turbo filter mask respiratory protection with an air supply. See section 6 for more information on the use of respiratory protection.