Cleaning Parking Lots, Sidewalks, and Outdoor Areas

When visiting a restaurant, supermarket, furniture store, shopping center, doctor's office, or a museum, guests typically begin by parking their car and walking to the building. Several strategies can create a positive first impression, decrease the risk of accidents, and limit the amount of dirt brought in from the outside.

A contract cleaner uses a Kärcher ride-on sweeper to clean the outdoor area of an office building.

Sweeping Outside Areas – Removing Loose Dirt

Dust and loose dirt should be removed from the parking lot and foyer using either push vacuum sweepers or ride-on equipment, depending on the size of the space. The vacuum function prevents dirt from being kicked up and, where applicable, deposited on parked cars or furniture, such as benches.

A worker uses a Kärcher walk-behind sweeper to pick up debris outside of a grocery store.

For smaller areas of up to 3,225 square feet, it is recommended that you select a walk-behind sweeper with a dirt capacity of up to 10 gallons.

A worker uses a walk-behind sweeper to maintain the clean appearance outside of a department store.

For medium-sized areas of up to 10,750 square feet, use walk-behind push vacuum sweepers with traction drive and an extraction system with a filter system, among other features.

A worker uses a ride-on floor sweeper to clean near a bike rack outside of an office building.

For larger areas spanning 16,000 square feet and more, use ride-on vacuum sweepers. These have a large container volume and some of them come with hydraulic high container emptying. For very large areas, including parking lots, municipal vacuum sweepers are a great alternative. 

An illustration shows how dirt is picked up with a ride-on floor sweeper.

The classic ride-on sweeper

As with all other tasks, not all sweeping is the same. The choice of machine and accessories is based on the surface, type of dirt, and the size of the area or distances to be covered. The classic ride-on floor sweeper tends to be used for a fixed range of applications, e.g. for individual objects such as parking lots or outside areas around multi-purpose halls. Moreover, the machine's side brush makes it very suitable for sweeping edges and corners. The collected road dirt is then picked up by the main sweeper roller. Sweepers can reach working speeds of up to 8.7 mph, enabling work to be completed quickly and effectively.

A municipal sweeper cleans outside of an office building.

Municipal and vacuum sweepers

Whether machines are powered by batteries, liquid gas, gasoline or diesel must be decided according to the area of application. For instance, smaller areas can also be cleaned using battery-powered machines. However, their limited climbing ability makes them less suitable, or even unsuitable, for steeper ascents. Municipal and vacuum sweepers use their side brushes to sweep up dirt, which is then vacuumed up through the suction mouth. These machines can be used to quickly clean larger areas and are also able to tackle extended sections of roads, reaching speeds of up to 25 mph. In addition, municipal machines can be used year-round since the cab offers driver comfort with features like air-conditioning, among others.


From the Sweeper's Accessories to its Filter

Using the right roller brush is vital when it comes to the quality of the sweeping. Harder roller brushes pick up larger and heavier dirt more effectively and are also suitable for use in damp conditions or on very rough floor coverings. On the other hand, soft roller brushes are more suitable for larger quantities of fine dust or light debris because they stir up less dust during operation. We particularly recommend using a soft roller brush on smooth and delicate floor coverings. In addition, it's not just the main sweeper roller which has bristles of varying hardness; this is also true of the side brushes, which have the same properties.

A water spraying system is shown above the the side broom bristles.

There are multiple methods for preventing dust from being kicked up.

On particularly dry, dusty surfaces, it is advisable to deactivate the side brushes and to only work with the main sweeper roller. If it is not possible to deactivate the side brushes, another way of considerably reducing the amount of dust stirred up is simply to reduce the working speed. In addition, depending on the machine, you can bind or reduce the dust by fitting attachment kits, such as a water spraying system, side brush cover, or speed regulation for the side brush.

Vacuum sweepers can be used in wet or rainy environments

In dry air conditions, this filter ensures that fewer fine dust particles escape into the surrounding area. When it is raining, you can either switch off the fan or guide the exhaust air around the filter using a bypass. The rain binds the dust and does not cause problems for the exhaust air.


Wet Cleaning of Outside Areas

There are a multitude of options for wet cleaning, including washing at low, medium and high-pressure, scrubbing with brush technology, and hot-water cleaning. Again, it is important to outline the most common application scenarios. Should this technique be used for daily cleaning of paths, or is it better suited to removing oily dirt? Which method is suitable for which application, and are there times when it's better to contact a service provider?

A worker uses municipal equipment with a washing bar to clean sidewalks.

Washing: The required result determines the pressure used

Municipal machines with a washing bar are often used for washing applications, while manually operated machines like pressure washers provide another option. In any case, it is always important to select the right nozzles and to adjust the pressure to the intended requirements.

Low pressure of up to 175 PSI is usually used for coarse cleaning. This allows you to bind large amounts of dust or to rinse off muddy roads after a storm. The available solutions are relatively inexpensive but do require a lot of water and sufficiently large tanks.

Medium-pressure washing is an option for versatile use. It has been found that pressures of up to 580 PSI are particularly suitable for maintenance cleaning on roads and pavements. However, it is not possible to carry out thorough, fiber-deep cleaning because the water pressure is too low.

High-pressure washing is often used for particularly tough cleaning tasks, such as intensive cleaning after a street party. The water penetrates deep into the pores of the surfaces at up to 3600 PSI and rinses them clean. Moreover, less water is consumed than during low and medium-pressure washing.

A worker pressure washes a trash can outside of a facility.

If a cold water pressure washer is used, it can also be used for the following specific applications.

This machine can remove stubborn stains and soiling, for example caused by moss, lichen, bird droppings, and leftover food. It must be ensured that, depending on the area to be cleaned and the dirt to be removed, there is a sufficient water volume available to effortlessly loosen and remove the dirt. 

Highly effective and versatile: Scrubbing with disc brush technology

Wet cleaning with brush technology is becoming more and more popular for outdoor areas as the requirements for this type of cleaning grow. In some cases, it is even a question of protecting high-quality road surfaces from deteriorating and maintaining them as sustainably as possible.

While either disc or roller brushes are used for interior cleaning, disc brushes are usually used for exterior cleaning. They boast reduced wear and tear, a high area performance, and also operate at a low rotational speed with low contact pressure. In addition, you can also use cleaning detergents to remove the dirty water in order to achieve the best possible cleaning result. Thanks to their maneuverability, transport speed, ground clearance and the all-wheel drive available on some machines, municipal machines offer considerable advantages in inner city areas with respect to their flexibility, quick availability, and wide range of applications compared to larger machines designed for industrial use.


Anyone who has their wits about them when purchasing machinery will look for a provider whose machines are versatile and can be used all-year round. The models should be able to sweep and wet-clean, as well as quickly switch between different implements. This allows you to schedule using scrubbing and sweeping units alternately in order to achieve the desired result, depending on the requirements for cleanliness.

If, in special cases, it is necessary to use cleaning detergents, it's worth contacting the application engineer or technical advisor at the manufacturer to establish the right combination of brushes and detergents to be used according to the condition of the floor and the level of dirt.

A contract cleaner cleans sidewalks with municipal equipment using disc brush technology.

For particularly tough cleaning tasks: Hot-water cleaning

Manual cleaning with hot water pressure washers is suitable for a range of surfaces and for removing different types of dirt. This includes, for example, effectively removing organic discoloration/growth or weeds, dirt caused by emissions, as well as leftover food and drink or their stains.

If you need a high area performance for cleaning floors, for example, you should not only consider the working pressure but, most importantly of all, the flow volume of the machine when choosing a suitable model. A surface cleaner is an ideal special accessory and may also remove the dirty water, depending on the model.

Moreover, the sweeper's versatility and range of applications can be improved thanks to the choice of machine type. For example, there are hot water pressure washers available with an electric motor or a combustion engine. There are also smaller, mobile machines, as well as trailer solutions. In this case, the pressure washer trailers have diesel or gasoline engines and sufficiently large water tanks, which allow users to work independently for up to over an hour, depending on the machine.

A contract cleaner pressure washes concrete steps to remove dirt and debris.

Safety first: What users should look out for

It is vital that the various cleaning techniques are applied correctly in order to prevent accidents at work. It is therefore important to know the risks. These include:

  • For washing applications, using a low pressure (up to 175 PSI) is non-critical; while at medium (up to 580 PSI) and high pressures (up to 3625 PSI and above), body contact must be avoided because the high pressures may cause tissue damage.

  • When sweeping and scrubbing, caution should be exercised when handling brushes. Appropriate protective clothing must be worn as the brushes can cause cuts, depending on their hardness.

  • If cleaning detergents are used, the safety precautions will vary depending on the concentrate, pH value, and surfactants. However, in all cases, you must always put water into the container before adding the cleaning detergent and ensure that suitable personal protective equipment is worn when handling the relevant detergents. This prevents pure concentrate from splashing upwards and causing physical contact and possible injury.

Gum Removal

Chewing gum that has been firmly trodden into the ground is tedious and difficult to remove. However, there are machine solutions, such as pressure washers and mobile steam cleaners, which provide useful assistance during this laborious work. If pressure washers are used, it must be ensured that there are water and power connections available, if necessary, and that the required hoses and cords do not pose a tripping hazard. The areas being cleaned must be cordoned off so as not to pose a safety risk.

In contrast, machines for removing gum enable interruption-free work over extended periods of time, reduce the safeguarding measures required, and can be used for a wide range of applications.

The cleaning detergent is heated up in the machine and sprayed onto the piece of gum. After a short contact time of just three to five seconds, it can be removed using water steam and the brush attached to the nozzle. Finally, it is recommended that you use a sweeper to pick up any loosened gum residue.

A worker removes gum from a sidewalk
An upclose image of gum removal in action.

Weed Removal

Depending on the subsoil, weeds can spread to a varying degree in public places, on footpaths or in parking lots. While hardly any weeds can penetrate through sealed asphalt surfaces, paved areas are much more acutely affected.

If you want to prevent weeds from spreading, you should remove the fertile ground for these unwanted guests. Weeds grow from pollen settling in dust and dirt and then sprouting as dandelions, thistles, etc. Regular sweeping is the most effective way of keeping weeds under control. Sweeping also means that the surfaces are well-maintained and there is reduced fine dust pollution. However, the necessary operational capacity has high requirements in terms of personnel and machinery. 

Methods for effectively removing existing weed growth include using hot air, hot water, water steam, and a weed brush, depending on the degree of growth. These methods are applied, for example, using suitable hot water pressure washers or with municipal machines in combination with appropriate implements. In addition, the grasses' natural growth curve should be noted so that work can be carried out at the right time. 

Weeds grow between rocks

Removing weeds

Tackling weeds effectively is a major challenge. Chemical products are available, but they are often harmful to the environment and can only be used in a limited way in public spaces. Dandelions, thistles, etc. can be removed using hot water and without herbicides – a procedure that protects the environment as well as surfaces.

Suitable Products for Cleaning Parking Lots and Other Outdoor Spaces