While preventing the risk of infection is important, hygiene in general – such as floor cleaning – are also taken into account in the hygiene schedules. It is also necessary to keep outside areas looking neat and tidy, through regular sweeping for instance, and to prevent dirt from getting into the building as much as possible.
Professional, systematic cleaning and care contributes significantly to extending the life of floor coverings. It is also one of the most important tasks in building cleaning. This applies above all to the deep cleaning or stripping of resilient floor coverings for which there are two methods that differ in the use of machines and cleaning time.
One of the most common types of flooring in schools is linoleum – a resilient floor covering. Linoleum is a natural product consisting of the raw materials linseed oil, cork powder, wood flour and a jute substrate. This type of floor covering has only limited alkaline-resistance (application concentration pH 10).
Deep cleaning with a scrubber drier
The two working methods for deep cleaning or stripping involve the use of either a low-speed single-disc machine or a scrubber drier.
To begin with, the basic cleaning agent (such as the Allround Deep Cleaner RM 754 ASF, pH 10.5) is applied in straight sections with a small overlap. During the contact time, the prepared surface is cleaned several times crosswise with the scrubber drier. If required, more cleaning solution can be applied in order to prevent the agent from drying.
A very good stripping result is achieved through the strong and uniform contact pressure (up to 210 g/cm²) over the entire working width, high speed (1,100 rpm) and excellent floor contact (roller pads). Thanks to the consistent efficiency of the green roller pads as a result of the self-cleaning effect, the stripping process is significantly shorter.
Once the coating residue is completely dissolved, the next step is to vacuum the dirty water using the scrubber drier – section by section. This is also much faster than the conventional method using the wet and dry vacuum cleaner and also saves time.
The floor covering is subsequently rinsed again with clear water with the scrubber drier adding clear water using the one-step method. Additional mechanical processing using roller technology ensures that any detergent residue is optimally removed from the floor covering so that the risk of “powdering” of the new coating through the detergent residue is prevented. The floor must subsequently be allowed to dry.
The drying time for the natural product linoleum is minimum 12 hours, preferably 24 hours due to a risk of the new coating separating from the floor covering (powdering) where there is residual moisture. For this purpose, the Air Blower AB 20 can be used with sufficient ventilation. This halves the drying time.
Coating
The respective material must subsequently be distributed carefully and evenly using an “applicator” or wide mop. It is recommended to apply the product transversely to the light and spread it lengthways. This ensures that the product is applied evenly. Depending on the absorbency of the substrate and level of wear, it is recommended to apply the coating a second time.
Also, to be noted: older floor coverings have the tendency to absorb the first coating to a large extent. The first coating can be walked on carefully after about one hour in order to apply the second coating. The floor covering can be walked on after two to three hours. The coating is dry and fully resilient initially after 24 hours.
Maintenance cleaning
Maintenance cleaning can take place manually or using a machine with Wiper Care Extra RM 780 in a dosage of 0.5-3%, depending on the degree of soiling. For maintenance cleaning with a machine, which delivers a much higher area performance, a scrubber drier is required using the one-step method. It applies the wiper care to the floor covering, brushes it in and picks up the dirty water in a single pass. Floor coverings are immediately dry.
Cleaning in outside areas
Preventive cleaning is playing an increasingly important role. This concept starts with cleaning operations in outside areas: thoroughly sweeping or washing open spaces can significantly reduce the amount of dirt brought into the building. As well as the pavement and parts of the street directly in front of the entrance, other areas to consider are car parking areas, playgrounds and recreational areas. These are areas where lots of dirt collects that can be carried into corridors, stairwells and classrooms. The concept of preventative cleaning pays off very quickly. Keeping exterior surfaces clean is much quicker and requires less work than cleaning the rooms themselves thanks to the fact that sweepers and highpressure cleaners can be used.
Abrasive mats with bristles are recommended for outdoor use, as they can be used to clean all manner of shoes – even those with a deep tread.
The size of the sweeper and therefore the efficiency of the cleaning operations depend largely on the size of the surfaces to be cleaned:
— Walk-behind push sweepers with a dirt storage capacity of up to 30lt are suitable for cleaning smaller surfaces of up to 300m²
— Walk-behind vacuum sweepers with traction drive (petrol/ diesel motor or batteryoperated) fitted with a suction element and filter system are used for medium-sized surfaces of up to 1,000m²
— Ride-on vacuum sweepers with a large container capacity and hydraulic high container emptying are used for largescale surfaces of 1,500m² or higher.
Aside from these options, cold water high-pressure cleaners are generally brought into operation if there are stubborn stains to be removed, e.g. moss, lichen, bird droppings, chewing gum or food residue. Care should be taken to ensure that enough water is available to easily loosen the dirt and transport it away from the area (600lt/h and higher). Hot water high-pressure cleaners are more adept at removing greasy stains. The cleaned surface also dries off much more quickly.
Gentle weed removal
Dealing with weeds effectively is a constant challenge. There are chemical products for this purpose, but these are bad for the environment and in countries like Germany are permitted for use in public spaces under very strict circumstances. Regular sweeping or solutions involving hot water, as well as mechanical brushes, are possible alternatives.
Prevention – regular sweeping
Prevention is the best cure to protect against the spreading of weeds. If you want to prevent weeds from coming up in the gaps between the tarmac and the curb, for example, regular sweeping is unavoidable. This is because it not only removes the plants’ seeds, but also the dust and dirt which, combined with rain water, create an ideal substrate for weeds.
In full growth – water and steam
Where high growth of weeds is not a particular problem, removal can begin later in the year. In this case, hot water is the most effective method. The water is heated to around 99°C and is around 92°C by the time it reaches the roots, unlike hot air, which only affects the plant itself. If temperatures above 65°C are reached there, an excess of ascorbic acid forms – which the roots transmit to the leaves, thereby destroying the plant. After treatment with hot water, the weeds look like wilted spinach; two to three days later and the weeds have completely reduced in size. This method can also be used on loose surfaces such as gravel or the red sand of sports grounds, unlike sweepers.
Alexandra Lachner
for Alfred Kärcher SE & Co. KG