Maintaining a facade

Cleaning and maintaining the facades of commercial and public buildings is no easy task and safety regimes and security are just some aspects which must be taken into consideration

5 August 2010 

The skylines of most cities in the UK and around the world are constantly changing as the design and construction of tall and complex buildings alters these cityscapes. New towers almost invariably incorporate glass facades, and access to them for maintenance and cleaning is always challenging and often not as carefully considered as it should be.

Key aspects to be addressed in relation to the exteriors and indeed internal atria of all commercial and public buildings are the cleaning and maintenance regimes, essential security regimes and safety of access.

The issues are: what is the safest way to provide access; what is the code compliant way to provide access; what level of access is required for what cleaning and maintenance regime; what safety regime will be most appropriate and how will it affect and interact with optimal facade access?

Openings to gain access in any facade create additional problems requiring the provision of safety eyes. They will also inevitably create disruption to the air conditioning systems of today’s super-sealed buildings. It is therefore preferable to provide access directly from and on the exterior of a building. The current economic climate and need to ‘value-engineer’ solutions, coupled with the impact of legal requirements, highlight the need for an impartial, independent service to advise on the solutions available and to distinguish between them. This is why facade access has become an area in which specialist consultants are required.

The recent and proposed changes in legislation, European standards, EC directives and the introduction of CDM regulations have emphasised the need for a more structured and informed approach to the provision of access and maintenance to the building fabric, than has traditionally been the case. For example, special consideration must be given to safe means of access for personnel to facade access equipment, usually by using safety systems to which harnesses can be attached.

Exterior access can be provided for in a number of ways, such as balconies, walkways, cradles, ladders, gantries or abseiling. In detail:
• From below using ladders or MEWPs (mobile elevating work platforms) in which case the ground conditions need to be able to take the loads
• From above using cradles, gantries or abseiling, all of which need some form of anchorage. It is preferable that loads do not impose up thrust loads or pull out loads to the building structure
Note: abseiling can impose greater, sometimes unanticipated, loads onto the building facade and structure
• Through the facade access – using opening windows or doors to balconies and parapets.

Health and safety 

The Health and Safety Executive (HSE) discusses facade access in various guideline documents such as the Workplace regulations, Loler regulations and Working at Height regulations. The HSE proposes a hierarchy of systems. The preferred option is to remove the risk; if this cannot be achieved, the risk should be minimised. This hierarchy is:
• Opening windows and/or balconies with full height handrails
• Cradles or MEWPs
 • Ladders
• Abseiling
The HSE’s basic premise is to produce a safe system and it requires project teams to design safe systems. Most inspectors consider abseiling should only be used if all other forms of access are not possible.

The CDM regulations also recognise that the priority is for a facade access system that it is safe and efficient. Provided it is both, there are then many methods of access to the facade and they all have an effect on the building to a greater or lesser extent. These days consultants are in a position to objectively assess, consider and recommend these.

The main features to consider are access to the system both in use and in an emergency and the method of fixing the system to the building. Each of these is vital. There are only a very small number of designers of effective systems in the whole construction industry worldwide.

Issues solution summary
• Cleaning and maintenance
With the shape of facades becoming ever more complex, the need for effective access systems to maintain and clean the facades has increased. If the equipment cannot access all the facade or operate effectively, the building will not be maintained and in time debris will build up spoiling the building’s appearance. Attention to detail and loads will resolve some issues, eg, winches in a cradle double the suspended load and hence loads into a building than a system that has the winches mounted on the roof trolley.

• Security and safe access – where access is required through a building there are issues of theft and if the operative is to use a window safety eye to climb through the window will he actually use the safety eye. Risk is high.
• Access in ordinary use and in an emergency – the design teams need to consider how the operatives will access the cradle from a place of safety together with how the maintenance engineer will access the unit at any point should it break down.
• The method of fixing the system to the building – eg, a bolted fixings trackless system or a freely laid system, the solution is dependent on the roof finish and reach required. Every building has to be considered on its own merits. There is no one size fits all here.

It is becoming clear therefore that it is important to consider facade access from the earliest stages of a building’s development as it will affect the architectural expression of the building. If, for example, the building is to have a flush glazing system the architect will not necessarily want the facade split with external walkways on every floor.

One final vital point is that even the facade systems themselves will only maintain the efficiency of the facade if they are correctly maintained and operated. If the equipment cannot access all the facade or operate completely effectively, the building will not be fully maintained, in time this will result in dirt and debris building on the facades, invalidating guarantees and insurances, threatening building material integrity and, of course, reflecting unfavourably on the prestigious architecture and the building’s occupants.

Stuart Bond is facade access expert at D2E International