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Detailed planning will cut accidents on refurb sites

Improving safety on refurbishment, repair and maintenance still needs specific methods. By Shelley Atinson-Frost

In 2006/07, 39 people died on refurbishment, repair and maintenance sites, half of all fatalities.

It is a big concern for industry and Government. During July/August 2007, the HSE targeted inspections of refurbishment projects and work was stopped on a number of sites.

It is planning further visits in 2008. In September, minister Peter Hain held a Construction Forum and key industry representatives agreed a framework for action to drive forward improving health and safety, with particular focus on refurbishment.

Recognising the complexity of a refurbishment project is key, as is an understanding of the potential challenges and need for proper information gathering, planning and management.

In the main, refurbishment work is less well-planned and more difficult to control than new build. The significant risks were demonstrated by recent collapses in Hull, Bootle, Stoke and Tottenham.

Planning The primary rule in planning the refurbishment of old buildings is that the fabric of the building cannot be assumed to be sound.

The client should ensure that as much information as possible about the building and type of construction is provided to the CDM co-ordinator or contractor. It should also allow enough time for completion of the preliminary assessments.

This information, together with details of hazards identified by surveys for the client (such as asbestos) or significant design assumptions, should be included in pre-construction information.

Survey Work should not start until an in-depth survey has been done to determine the real extent of deterioration and other hidden hazards that may not be known at tender.

The construction phase plan will therefore need to be reviewed and updated at each stage of the work after consultation with the principal contractor, designer and other contractors. The CDM co-ordinator must be advised of changes.

Each aspect of the work needs to be planned and detailed method statements produced where appropriate, especially for demolition, where the integrity of the remainder of the building, any temporary works required and a monitoring system for falsework should be taken in to account before demolition takes place.

All aspects of the work must be co-ordinated to achieve a correct sequence of operations. The British Standard 6187 ‘Code of Practice for Demolition’ is useful.

Structural refurbishment The structural engineer has to provide the structural design and do the preliminary structural surveys.

For any structural alteration, the original design documents and all available construction and operation records must be reviewed to obtain a thorough appreciation of design and structural integrity.

The structural appraisal should report on the condition and strength of the load bearing members along with remedial measures and supporting calculations to satisfy the requirements of the Building Regulations. Unplanned collapses during demolition usually occur because of poor a understanding of structural behaviour.

Facade retention The facade needs to be held in its original position during work. Stability can be achieved by use of various systems including vertical or raking shores, horizontal wind girders and kentledge.

The design of such systems should be carried out by suitably experienced chartered civil or structural engineers.

Temporary works Poor planning and management of such work could easily give rise to a dangerous situation. If the main load bearing walls are to be removed or radically altered, there will be a need for supporting falsework.

The major problem with refurbishment is where to transmit a load to an adequate support.

It is vital that the foundation aspects are dealt with as a priority and completed prior to alterations to the main structure. It is also essential for each situation to be carefully assessed and all falsework designed by a competent person.

Any underpinning and foundation work must be conducted under the supervision of an experienced structural engineer as the imposed loads can be deceptive in older buildings.

A temporary works co-ordinator may be essential to ensure stability throughout the interim stages of the building work.

Work at height Scaffolding requirements are often different for this type of contract. The main structure is already in existence so scaffolding for roof work and external repairs, for instance, is often taken immediately up to roof level and work is then carried out from the top downwards.

Further, there are difficulties in tying the scaffold into a possible unsound structure. Moveable ties rely on the strength of the structure for their security.

Where non-moveable ties are to be used, it is essential that tests are done as recommended by the anchor manufacturer.

Electricity All services including electrical services must be identified and checked carefully.

All circuits should be correctly isolated to ensure that they cannot be inadvertently energised while people are working on them.

It is wise to have temporary supplies provided and where existing services are to remain live Đ their positions must be located and clearly marked.

The site electricity supply for portable tools and lighting should be 110 V - so a 240 V supply should be transformed down to 110 V.

Rot and timber infestation Major structural problems can arise from timber infestation, which can result in a reduction in the load bearing capacity of the structure.

When dry rot or beetle attack is suspected, a thorough inspection should be carried out by a competent person to ascertain whether the existing structure is capable of taking the loads to be applied or whether the timber must be replaced.

Temporary support may be required prior to an inspection taking place.

Occupied premises When working in occupied premises, the health and safety of the occupants must be considered as well as that of the workforce.

Key observations include:

  • In housing, services will often have to remain connected Đ beware of live electrical terminals temporarily uncovered;

  • A permit to work system should be put into place where wet trades are carried out near live electricity;

  • Never leave work unguarded at the end of the day if it is likely to be a danger for the tenant.

Good order A significant number of major and over three day injuries occur on refurbishment sites due to slips and trips.

Sites should be kept tidy and clear of obstructions over which people may trip and fall.

A clear policy should be established and communicated on issues including designated waste areas, frequency of clearing, individual responsibilities and others.

Rubbish chutes should be used where possible to dispose of non-hazardous waste.

It should be properly installed - usually by scaffolders - and used with a hopper at the upper end and skip at ground level.

Chutes, together with suspension fittings and attachments should be examined for defects before erection and inspected at least at weekly intervals while in use.

To avoid blockages, there should always be a clear space of about one m before the bottom chute section. A safe system of work is required for installation, dismantling, clearing of blockages and maintenance. There should also be a safe means of access and safe place of work.

Communication Communication of information - especially risk information - is critical.
Communication relating to the existing structure is vital for the development of an accurate structural design as well as the selection of demolition methods.

Safety issues and instructions must also be effectively communicated to workers. This information must be organised at all the different levels and stages of the project and take into account the frequent changes in site activity.

Shelley Atkinson-Frost is health and safety advisor to the Construction Confederation