Cleaning cladding and façades without people
October 1st 2004 Rob Burnett, managing director of Kaizen Contract Services who led the in-house team that developed Kai-Wash, explains how the new system for cleaning buildings works
Is it really possible to clean every millimetre of a building’s external panels or structure? Until now, such a claim would be doubtful because abseiling,working from a scaffold tower, cradle or mechanical boom is too restricting to maintain a consistent cleaning pattern.To overcome this,we have developed systems and equipment with which we can guarantee that no matter how tall the building, every millimetre of its external surfaces can be cleaned.
Called Kai-Wash, it features a purpose designed lightweight device, not dissimilar in appearance to a cradle, temporarily suspended from the roof of a building. It contains only hoses – not people – attached to a custom built service vehicle at ground level. It is able to climb the building on a dual fail-safe rope system. Installation takes approximately half a day depending on access.
The cleaning action is entirely by hot water pumped under pressure through our specially designed spray heads which jet the water at critical angles on to the outer surface of a building to attack the dirt and grime – first by loosening it and then getting under it to remove it completely. Brushes are not used, nor do we normally use additives or detergents.
The design of the spray heads and the angles, temperature and pressure at which the water is applied are the result of over 15 years’ experience of using high pressure water systems to clean the exteriors of large buildings. Just recently,we completed the cleaning of the entire façade of Imperial College in London – all 70,000 ft2 of it.
How can we be so sure that every millimetre of a building’s surface is cleaned? Because the way we jet water ensures that every point on the surface is cleaned at least ten times in the Kai-Wash cleaning cycle – and because of the speed of cleaning, relatively little water is used; if no detergents are involved, the water can go directly into surface drains.
The result is a system capable of cleaning vast areas of external surfaces to extremely high standards – we estimate at least three to four times faster than any other method and with significant cost savings when compared to conventional façade cleaning.
There will be some, perhaps many, in the trade who will be sceptical of these claims, but if you think how robotics have revolutionised manufacturing processes in terms of quality, efficiency and speed and then apply the principle to the cleaning of buildings, you can begin to see why our claims are not based on false modesty.
How it works Like many good ideas, the thinking behind Kai-Wash is straight forward – to develop a simple, safe, thorough, highly efficient and cost effective system for washing cladding and façades.
The Kai-Wash cradle is suspended from a roof structure by a dual failsafe rope system and fitted with hoses that are attached to a large hot water pump in our service van that can generate up to 345 bar. It can heat water to 100°C, although normally water is applied at 60°C. Water pressure, flow rate and temperature can be adjusted remotely from the ground.
Installation, safety Because Kai-Wash is a complete system for cleaning buildings,we designed it around our own expertise – for instance, only our highly qualified and safety conscious rope access technicians, who are all IRATA trained, are allowed on the roof of a building to install it. They are also responsible for setting up safe temporary systems of attachment when the roof does not have its own fall arrest system.
Once on the roof, additional equipment is winched up. Moving the Kai-Wash cradle on to the next section to be cleaned can take as little as two minutes.There is no restriction on height for the Kai-Wash system – as part of the safety brief, the cradle has been engineered to work at greater heights and with greater forces on the roof equipment.
As with any safe rope access,everything has at least two independent points of contact. In addition, the Kai-Wash cradle also uses a safety inertia reel so that if anything were to fail, it can be lowered to the ground at controlled speed. This ensures the safety of the operators below. More articles from Kaizen Contract Services: | 
