Carry out asbestos removal ensuring airborne asbestos fibres are kept to a minimum (i.e. appropriate tools, wet removal, minimise breakage, good handling techniques).

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Removal of Asbestos Cement Products (Internal)

The contractor should carry out this removal wet (using fine water spray of PVA) unless not practicable, for example, where an electrical hazard may be created.

A P2 or P3 filter with a half face piece respirator should be minimum respiratory protection used for this work. Decontamination procedures should be followed at every work break.

During any work in the work area prior to clearance, coveralls worn should be made from either 100% synthetic material or a mixed natural/synthetic fabric capable of providing adequate protection against fibre penetration. All fabrics must be capable of preventing the penetration of asbestos fibres down to a diameter of 0.5 micron and to a maximum 1% penetration of all airborne asbestos fibres. Once worn, disposable overalls are not to be reused or laundered.

Air locks should be placed on entrance doors to the work area comprising at least three sheets of plastic. In addition, a protective layer of plastic woven poly vinyl (200 micron minimum thickness) should be taped over any carpeted areas within the work area. These air locks should be used for preliminary decontamination (vacuuming of overalls) prior to proceeding to the decontamination unit.

Where asbestos cement is behind ceramic tiles, sufficient tiles are to be removed to give access to the fixings of the asbestos cement sheets. This work is to be performed such that minimum damage to the sheet occurs.

Sheeting should be thoroughly wetted down with a fine spray of water before commencing removal. Nails should be cut with a cold chisel under the edge of the sheet or cut around the head using a punch, causing minimum damage to the sheet. If necessary, nails are to be punched through the sheeting to facilitate effective removal. Nails should be removed from the timber framework following this procedure, using pliers/nippers or similar device. Small sections of contaminated timber around the nail should be chiselled out and disposed of as asbestos waste.

No high speed power tools, that create dust should be used unless permission to do so is granted by the Asbestos Assessor following discussion with the supervising Competent Person.

Sheets should be removed with minimal breakage. Unnecessary smashing of asbestos cement sheeting shall not be permitted. Once removed, the back of the sheet should be wetted using fine water spray.

Following this removal process, the sheets should be wrapped in 200 micron minimum thickness polythene sheeting and taped prior to removal from the work area (placement into a waste skip which has been lined with double layer of 200 micron thick polythene). The external surface should be wet wiped to remove any adhering dust before the bags are removed from the work area.

Smaller pieces of sheeting and asbestos cement debris should be placed in heavy duty 200µm (minimum thickness) clear polythene bags. These bags should be labelled with an appropriate warning to the effect that the bags contain asbestos and that dust creation and inhalation should be avoided.

Under normal removal conditions, this form of work does not carry a recommendation for extraction ventilation. The work area should be roped off and sign posted in order to restrict public access.

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Removal of Asbestos Cement Products (External)

With the exception of asbestos cement roofing, contractors should carry out this type of removal wet using fine water spray unless not practicable. Roofing is to be sprayed with PVA prior to the removal process. PVA must be dry before commencing sheet removal in order to avoid a slip hazard.

Before any removal is undertaken, the areas should be roped off at a distance of ten (10) metres clear of the work site or as arranged and approved by the superintendent.

The roped off areas should contain the decontamination area and skip for the storage of all asbestos contaminated waste. The skip should be emptied at regular intervals and when left overnight, should be sealed up and secured to the satisfaction of the superintendent. No asbestos waste should be allowed to remain on site over weekends or holiday periods. Roped off area should display an adequate number of warning signs and a supervisor should be on hand at all times to see that all personnel inside the work area are wearing protective clothing and respirators and should prohibit all unprotected personnel from entering the work area.

A P2 or P3 filter with a half face piece respirator should be the minimum respiratory protection used for this operation. Decontamination procedures should be followed at every work break during work.

During any work in the work area prior to final clearance, coveralls worn should be made from 100% synthetic material or a mixed natural/synthetic fabric capable of providing adequate protection against fibre penetration. All fabrics must be capable of preventing the penetration of asbestos down to a diameter of 0.5 micron and to a maximum 1% penetration of all airborne asbestos fibres. Once worn, disposable overalls are not to be reused or laundered.

Where necessary to access building eaves, scaffolding in compliance with the statutory regulation and codes or mobile equipment such as a “cherry picker” should be used. Where roof sheeting is to be removed, this is to be performed using scaffolding, or mobile equipment where removal is to take place from the underside of the roof.

Where moss is encountered on roof sheeting, caution should be exercised in the use of water and to the workers footwear. In these instances, the contractor should confer with the superintendent prior to commencing the work. Roofing sheets suspected to be present in inaccessible locations such as wall cavities and removal cannot be achieved without structural damage to the building, such areas are to be documented for future reference and the locations sealed and labelled to prevent any waste escape.

Roof sheeting should be lowered to the ground with the use of slings and lifting equipment, such as a crane. Once lowered to the ground, sheets should be wrapped in 200 micron polythene sheeting and placed into the waste skip. The skip should be double lined with 200 micron minimum thickness polythene.

Dropping of sheets or the use of ramps, chutes or similar gravity dependent devices should not be allowed under any circumstances. This removal process should be conducted in accordance with the Code of Practice for Safe Work on Roofs.

Spray Method

This method shall be used only where relatively small quantities of asbestos-based materials are to be removed and where the following conditions apply to the material:

• The asbestos-based material is not covered with other materials such as calico or metal cladding which require prior removal
• There is no reinforcing wire or other similar restrictions to removal
• The asbestos-based material is not coated with paint or mastic
• Where rapid temperature drop due to excessive water could cause damage to heated metal components
• Where no live electrical conductors are present and where no damage to electrical equipment can arise from the ingress of water

The spray shall be applied in such a manner as to ensure that the entire surface of asbestos-based materials is wet, but minimal run-off occurs.

In many instances, it would be helpful if a wetting agent (surfactant) is added to the water to facilitate more rapid wetting of the insulation material.

It is desirable for the asbestos-based material to be wetted through its full depth and maintained in a wet condition. It is recommended that a manually controlled, consistent low pressure, coarse spray such as from an adjustable, pistol-grip garden hose be used for this purpose. The design of the spraying equipment will be dependent on availability of water supply and access to the area to be sprayed.

It is important that the spray should be copious, but not such that the water droplets generate dust from impact with the surface of the insulation. When using cutting equipment to remove asbestos, the water spray should be directed at the site of the cut and the wetted material removed as the cut progresses.

The wetted asbestos-based material should be removed in sections and immediately placed in suitably labelled containers and properly sealed. Any small sections which may be dislodged should be collected and properly disposed of.