Facade Access Systems
While the construction industry in India has graduated from 20 to 60 floors, the façade cleaning sector, to a large extent is still comfortable with the rope access system for cleaning and building maintenance. Most often, be it hotels or commercial complexes, the façade cleaning and maintenance is outsourced to facility management companies or private contractors. FM companies again outsource façade cleaning to contractors.
Not all buildings are equipped with a permanent means of access to maintain the façade. Hence, private contractors who are equipped with a team of several trained rope climbers and rope access systems or other temporary access systems have been offering façade cleaning services on a monthly basis.
The increasing number of complex high rise building structures, absence of clear maintenance access systems and the dearth of professional rope climbers are giving rise to several risk factors. Accessing a building of say 20 floors using the rope systems is feasible in many cases “but how can you ask a worker to go up 40 floors without proper access system”, argues Ashok Khemlani, Managing Director, Cradle Runways India Pvt Ltd. Today, high rises are installing various façade access systems not just for cleaning but also for regular maintenance, planned preventative maintenance, repairs, breakdown and standby services, besides speedy access and construction.
Permanent Access
Monorail Systems: Monorail systems in certain cases offer an excellent alternative to the traditional BMUs. For recessed or overhanging facades, for buildings with a sloped roof and for cleaning the inside of glazed atria such as those covering modern commercial centres, monorails combined with cradles suspended from manual or powered trolleys are sometimes the only practical solution.
Ladder Systems: A wide variety of solutions use ladders and platforms which are either vertically mounted or sloped, guided along rails and designed to blend in with the shape and colour of the background of the building. Control is carried out using the manual control or the winch drive.
Mobile Suspension Systems: These are portable suspension systems mounted on bases permanently fitted along the roof. Mobile davits, as they are called, allow the cradle to be moved from one section to another to reach the different areas of the building’s facade and to be stored on the roof.
Gantries: These can be used to clean glass roofs and façades from the inside and the outside. These units move electrically and mechanically. If required they can be equipped with telescopic ladder towers.
Temporary Access
Temporary Suspended Access System is designed for temporary access typically for façade installation and maintenance. It consists of a lightweight platform which comes with specific load bearing capacity adhering to safety norms.
A key difference between the two systems, Permanent and Temporary, is the safety features and protection provided in the cradle as compared to a platform. The selection of any means of access solution for façade cleaning depends on such factors as: the building design, capital cost of equipment invested and costs of incorporating systems into the design of the structure.
Contemporary constructions are built with complex geometries, making it difficult to access certain areas while cleaning. Such buildings require roof cars in order to accommodate multilevel rigging. A motorised roof car system also provides complete horizontal movement via roof mounted track system.
Suspended access equipment, permanent gondolas that are put in permanent cradle, ground up equipment like the aerial platforms… all these are larger varieties of the existing systems.
Today, temporary suspended platforms are more in use in construction and soon bamboo scaffolding will become history, says Khemlani.
“The complete outlook of handling a building at a height is changing and that necessitates many installation of access equipment at the time of construction and also for the subsequent use and maintenance,” opines Khemlani.
More and more builders and contractors are looking at the access systems, for it offers a profitable proposition. The pay-back period is not more than the first few years of operations while its estimated operation life is over 20 years. “This has changed the outlook of builders and contractors, who cannot do without mechanisation in high-rise buildings. The change in the nature and attitude towards mechanisation is so much that they have started using the same techniques even in low-rise buildings. This in turn is changing the way they build,” he adds.
“The front runners look at state-of-the-art and highly functional façade equipment of international standards. Cradle Runways has provided these systems at Chennai TechPark, ITC Gardenia, Bangalore; Nehru hotel, Delhi; Trident Hotel, Mumbai and Oberoi Builders among others.”
At the same time, even though people are opting various access equipment they eventually buy them without realising the limitations and purpose of such equipment.
“People are ignorant and tend to use the equipment for anything and everything. They do not realise that a façade cleaning equipment is for cleaning and not for carrying loads up the building. It’s not a vehicle transport that can be overloaded.”
Quoting an instance, he explained that people carry a pile of grass three times the size of the truck and call it light weight. People overload anything that is mechanised. This gives rise to various safety issues; as such mishandling of access equipment could lead to accident or even loss of life.
“The cradles or the gondolas (word from the East) is a façade cleaning system and can only carry designed load. The Building Maintenance Unit is meant only for maintenance and does not have provision to lift building material or glass. This again could damage the equipment.”
Methods of Cleaning Facades
The three methods of cleaning facades are water, chemical and abrasive treatments. Abrasive treatments, such as grinding, sanding and blasting are not suitable because they remove surface material along with dirt and paint. That leaves water and chemical treatments, both of which are effective and safe when properly used.
Water
There are three kinds of water-based methods for cleaning facades:
- Pressure washing
- Soaking
- Steam / hot-pressurised washing
Properly applied, water treatments are the least invasive types of façade cleaning and a conservative way to start the job, especially when dealing with typical dirt and grime.
The most common method is pressure-washing, in which you apply a low- to medium-pressure spray (100 to 400 pounds per square inch) to the surface of the building. The water pressure usually starts out low and is increased as needed, followed by scrubbing with a natural or synthetic (but not metal) bristle brush for stubborn areas and detailed elements.
Sometimes a non-ionic detergent (the type used in dish-washing liquids, which foams less than ionic detergents and does not react with ions in water) is added to the water to remove oil-based dirt from surfaces. Soap and other household detergents should not be used in water-based cleaning because they can leave a visible residue on the masonry.
Soaking involves spraying or misting the masonry surface for an extended period, usually up to several days at a time, to loosen heavy accumulations of soot and crusts, particularly in parts of the building not exposed to rain. Soaking, used in conjunction with pressure and followed by a final water rinse, requires repeated applications that can take up to several weeks. But because it’s mild, it’s ideal for historic masonry.
Steam or hot-pressurized cleaning, is not commonly used but it can be effective for removing built-up soil deposits and plants, such as ivy. It’s also an option for cleaning stone that is sensitive to the acids used in some chemical cleaners.
Chemical Agents
Chemical cleaners are effective for removing dirt, and unlike water-based treatments, they can also be used to remove paint, coatings, metallic stains and graffiti. Acid-based cleaners are effective on unglazed brick and terra-cotta, cast stone, concrete, granite and most sandstone. Alkaline cleaners are best used on acid-sensitive masonry, such as limestone, marble, polished granite and calcareous (chalky) sandstone.
Both types of chemical cleaners are sprayed or brushed on a wet surface and allowed to sit for a period of time. Depending on the substance being removed, several applications may be necessary. Both types are rinsed off with water; alkalines are given a slightly acidic wash first to neutralize them.
Preparation
Before beginning a façade cleaning programme, it is important to identify the types of masonry on the building and select the most appropriate cleaning method for each type. Distinguishing among different types of stone is especially crucial. Certain limestones, for example, can look like sandstone, and what looks like natural stone can be cast stone or concrete. Some bricks may contain impurities, such as iron particles that can react with certain cleaning agents, resulting in staining. Choosing the wrong type of cleaning method can cause irreversible damage to the building materials, so when in doubt, it’s best to consult with a historic preservationist about the masonry’s composition.
Also, be aware that some chemicals (and even water) that are safe for masonry can corrode or damage other building elements, such as decorative metal elements, glass, wooden window sashes, iron window bars and window air-conditioner sleeves. Any parts of the building not subject to cleaning but susceptible to damage should be covered or otherwise protected.
Why BMUs
BMUs are not necessarily essential for all kinds of buildings. They are most suitable for high rises and terrace periphery is suitable for common motorised roof equipment, says Khushru Tampal, Mazda Hospitality Services, a facility management company based in Mumbai.
“Besides, not every building has necessarily got a BMU,” asserts Rakesh Lal, Proprietor, Classic Appearance, a facility management company based in New Delhi. It depends on the requirement of the building’s design and risk factors and sometimes on the client. “We have seen simple five to six-storey buildings with trolleys. We have also seen multi-storey buildings or more than 10 floors where BMUs are essential and there are no systems installed. I think it depends on the mind set of the architect and building owners. In my view, both BMU and spiderman system are safe means of cleaning façade, if handled professionally.” Apart from the height of the building, the choice of the BMU system also depends on the complexity of the façade and the space available on the terrace. “In many of the cases BMU may not be efficient and a cost effective system,” says Khushru.
BMUs are not just used for cleaning the façade but in maintaining the exteriors too. In the event of a crack or a breakage in any of the glasses, it can be easily replaced if the access system is in place. “In the absence of a proper access system, maintenance of the building façade becomes an expensive affair,” says Samir Khan, Managing Director, Window Washers, Mumbai. The company is directly servicing the hotel sector and is working with FM companies in commercial buildings.
In fact, when it comes to replacing just a single glass of the façade, no vendor would want to take up the job. Simply because the expense of installing the glass would be more than the glass itself, explains Samir. With proper access system in place, it is easier for the vendor to replace glass or clean it up. Even though it is not cost effective to attend to one glass in buildings, the hotels with no access systems are still prepared to spend money for the replacement of even one glass because a broken glass can mar their image.
According to Khushru, there are mostly four types of façade access systems that are attached to a building structure for cleaning and maintenance:
- Manual: Jib/Davit with Manual Gandola
- Semi Motorised: Jib/Davit wit Motorized Gandola
- Fully Motorised: (BMU) Motorised Terrace Trolley & Motorised Gandola, Monorail with Motorised Traversing Rollers & Motorised Gandola.
- Spiderman Technique
In Mumbai, Mazda is working with the simple eye bolts & spiderman technique at HDFC-Chandivali; Aluminum quick fit staging/scaffold at the Times of India-Kandivali; Special purpose tailor made equipment at Bayer Crop Science; Monorail system at ICICI Ventures; Trackless trolley at AMBIT and Purpose made trolley system at Raheja Bay.
“The other methods utilised to access the façade for cleaning include ground supported equipment like electro-hydraulic platforms, access ladders, aluminum quick fit staging/scaffold, Z-boom lifts and aerial lift.”
Mazda is also using trolleys, jibs, scaffoldings, aerial platforms, telescoping rods and access rope (spiderman system) at various sites. “At Unitech or the Asia Pacific Institute of Management, where the BMUs are in place, we get to use them.”
Cleaning aids/schedule
Cleaning as such should be done with quality products, believes Khushru. “The basic things required to actually clean the façade are glass applicators, glass squeegees, scrapers, buckets, dusters and glass cleaners & chemicals to remove the silicon and water marks from the surface.”
The need and frequency for cleaning facades depends on the type of industry. The hospitality industry and malls need regular cleaning while other industries can make do with quarterly or half yearly cleaning schedule. Besides the frequency, Rakesh feels, facades should be cleaned only at the scheduled time of the day. “One should not clean the glass under direct sunlight. Schedule should be made in accordance to the angle of the sunlight and shadow of the building. Cleaning should also be avoided when it is raining.”
“It is better to clean every alternate month but that again depends on the clients. Some clients are very particular about regular cleaning while some are not,” opines Khushru.
“In the hotels, façade cleaning is all the more important, as the room charges are based on the view outside. From the outside of the hotel, glass may look clean but from inside the room, even a small speckle can mar the view. Hence, regular cleaning is unavoidable. Our trained boys are employed on a monthly basis to clean the hotel façade regularly. If it is a big hotel, one round of cleaning would take a month to complete while in smaller hotels we can finish at least two rounds in the month,” explains Samir.
With offices in Mumbai, MP and Kolkata and operations all over India,Window Washers is cleaning hotels like Four Seasons, Grand Hyatt, Tunga Hotels and Royal Palms Hotels. Most of the hotels do not have the access systems and “we use the spiderman technique or the gandolas”.
The cleaning of a façade depends on how fast the job needs to be done. “At Four Seasons, we have placed six boys who complete cleaning the 34-storey building in one month. In case the client wants it to be completed in 15 days, we can always deploy more staff and systems and get the work done.”
Gandolas are neither easy to use nor are safe and have led to many accidents, says Samir. The company employs around 50 trained façade cleaners and uses around 40 systems. The rope systems are both locally made and imported but are CE approved (European Certification).
At Classic Appearance, more than 100 men are trained in the spiderman technique. These workers are first initiated as helpers at the site for at least two to three months before letting them do the actual job. At the training session the workers are taught how to tie the knot to the rope, where to tie the rope, how to use descenders and about fall-arrest, harness, carabineers and safety belt. In fact, there is a huge gap between the supply and demand of such workers. To an extent there is a monopoly of the spiderman technique in façade cleaning even though it is a very risky job,” opines Rakesh.
Indian scenario
“In India, it is not mandatory or statuary to put up the Façade Cleaning System, which is not the case in other countries. It all depends on choice of a client. Now there are more and more clients willing to spend for dedicated system. Developers and corporates have realised that, it is better to clean façade regularly rather than spending a lot of money in replacing the façade at a later “In India, it is not mandatory or statuary to put up the Façade Cleaning System, which is not the case in other countries. It all depends on choice of a client. Now there are more and more clients willing to spend for dedicated system. Developers and corporates have realised that, it is better to clean façade regularly rather than spending a lot of money in replacing the façade at a later date. They have also realised that for replacement of façade at any given stage will need proper façade access/cleaning system, rather than erecting scaffolding. The façade cleaning system can also be used for installation & future maintenance work, ” explains Khushru.
Rakesh adds, “There is a huge market for façade cleaning in India but more than 80% of the market is captured by the unorganised sector. There are instances of clients getting their façade cleaning done by the traditional “Jhoola walas”, who work at a very low price. On the other hand, in places where trolleys of any make have been installed, only 20% are in working condition while 80% trolleys / BMUs have broken down. There is a huge shortage of trained mechanics to handle the installation and operations of these permanent solutions, i.e. trolleys / BMUs. India needs more professionals and trainers to develop more number of technicians to bridge the gap between supply and demand of BMUs.
High rises should have BMUs
The geometry of building envelopes day-by-day are getting complicated. There needs to be a system to reach the place on the façade to clean and maintain the glass, says Mahesh Arumugam, Managing Director, Meinhardt Facade Technology, Chennai. Leading façade consultants across Australasia, Meinhardt has presence in about 28 countries and has a staff of over 3000. “A regular cleaning cycle is a must for such structures because dust settles on glass. If one tries to clean the glass after a long period, the glass could develop scratches, the sealant may get damaged or the glass could deteriorate. In order to preserve the performance of the façade, in terms of air infiltration, water leakage, etc., periodical cleaning is essential. This will give the façade long-lasting life.”
Talking about the type of BMU which depends on the building envelope, Arumugam says, “The design element of some structures is such that façade access becomes difficult.” In designs where every floor is shifted at an angle by a few metres to the inside and the distance between the top and the ground floor is over 30m, the access to the inclinations even with the rope system becomes difficult. “Hence in such cases we have recommended installation of winches.”
Any BMU system has to be planned at the concept schematic stage itself.
“In case of high rise vertical buildings, roof-mounted BMUs are ideal, as one cannot put up self-climbing cradle above 40m. This is because of power fluctuations above 40m. Otherwise the cradle could go off the wheel. It cannot restrain. In case of inclinations in design, cradles could be used with proper guided channels inside the façade. This can be done two ways. One with the channels designed inside the extrusion so that the four-wheel roller can run with the hose and the cradle can hold parallel to the façade with a 250mm gap. Alternately, the cradle could run with the controlled rope.
“In case of a stone facade, at every three-metre height, there should be tie-back points at the junction of the granite so that the cradle can tie back to the façade.
Some clients are positive and install the BMU at the schematic stage while some others do not plan and are sceptical to invest on such systems. In such cases, clients depend on the facility management companies and vendors who are given the maintenance contract. “These vendors go up on gandolas or use cradles with counterweight on the rooftop. In the absence of BMU systems, such alternatives lead to accidents and maintenance turns into a risky affair. It is essential that architects look at the BMU systems at the drawing stage itself, especially in the case of high rises. Vendors are not very experienced to clean very tall buildings and they tend to go in for temporary alternatives which can lead to loss of life.”