Welcome to the Ultimate Auckland Commercial Building Wash Guide. You will gain an understanding of the equipment and tasks involved in all types of commercial building cleaning techniques, from small to large. This guide covers the building wash equipment and licenses as well as different commercial surfaces, windows, glass and abseiling. This guide provides a general overview on some of the common aspects of commercial building cleaning. It does not, however, replace experience or common sense.

Commercial Building Wash Services Guide, Auckland premium painters

Commercial Building Cleaning: An Introduction

You should have an understanding of the exterior cleaning techniques, including water blasting and soft washing. Also, you need to be familiar with height safety, water blasting and soft washing equipment.

Learn how to wash buildings

First, you need to understand the purpose of building cleaning equipment and chemicals. The second step is to become familiar with the different techniques for removing dirt, mould and moss. Thirdly, hundreds of materials and products are in various stages of weathering and aging. They have also been subjected to a variety of different maintenance methods.
The main causes of damage or error in the industry are complacency, carelessness and underestimating how difficult it is to wash some surfaces. You can get a solid foundation in the industry by becoming proficient in residential building cleaning. It presents all the challenges that come with commercial building cleaning, but in smaller bite-sized pieces.

Why clean a commercial building?

Washing the outside of a building is important for many reasons. A shopfront or an office with clean, clear windows will look more appealing to passersby. Clean signage also shows potential customers that the shop or office is proud of their appearance. A building exterior wash can be a great way to prolong the life of your building.

The surface area around a building. The build-up of contaminants such as diesel dust, mould and moss, bird droppings, dust and debris from construction, and general degradation of organic material like leaves and pollen, will all contribute to the faster degrading of surfaces around a building.

Building Washing Equipment

We all know that having the correct equipment will help to reduce the amount of hard work and time required to complete a project as well as improve the quality of the final product. The same is true for building washing and water blasting. This section covers some of the building wash equipment, and what they are used for.

Water Blasters

To wash commercial buildings successfully, you will need a variety of equipment. First, you will need a variety of water blasters. You’ll want to be able to adjust your pressure and flow to effectively wash the building.

High Flow Water Blaster for Building Washing, Roof Washing

You may need to spend a long time using a waterblaster for a job involving a commercial building. If you are doing commercial roof washing, washing large buildings or concrete, then a waterblaster with a high-volume pump is needed. Around 25 to 35 litres of water per minute. Lower pressure helps to protect the surface of a roof while it is being washed. You can work faster with the high flow.

Your equipment may be too small for a large, extra dirty commercial roof washing job. This can damage the roof surface and cause you to lose days of work and disrupt your client’s operations. Auckland premium painters commercial roof wash waterblaster of choice is the Honda GX690 with a high-flow pump of 25-30 Litres per Minute and pressures of 2000-3000 PSI.

Commercial high-flow washing is made easier by using the correct fittings and accessories and good washing techniques. Some building wash operators prefer to use poles with ball valves to avoid triggers. However, this is not the best building wash practice as they can be easily dropped or switched on without an operator. Unmanned attachments can spray uncontrollably and cause flooding, damage and injury. It is safest and most effective to use a lance with a straight end of 1.2m to 1.6m, connected to a standard trigger. Straight water blasting lances take a lot of kick out of lances and reduce stress on your body.

The high-flow water blasters can also be used in conjunction with a surface cleanser aka whirlaway to clean large concrete surfaces.

Medium Flow Pump and Water Blaster for General Tasks and Building Cleaning

Medium sized equipment e.g. GX390 is an all-round machine with a pump that can deliver 15 to 20 litres per minute. It is ideal for retail buildings, small commercial buildings and roofs up to 1000 Sqm. This machine size is perfect for decks or small paths up to 100 Sqm. This lower flow waterblaster and pump will take a lot of time to use on large roofs or surfaces.

Abseil Building Cleaning / Roof Access with Small Low Flow Pump & Water Blaster

It is convenient to have a small water blaster on hand for washing abseil equipment. This allows you to easily transport the equipment through manholes and onto roofs. It is easier to control the lower flow when washing with ropes. Soft washing is also a great option for small machines, especially if you’re washing around wooden door or window frames.

Roof pre-paint preparation with a high-pressure pump and water blaster

Surface preparation is best done with a high-pressure water jet of at least 4000 PSI. The high pressure water blasting is the best way to remove any lichen and its roots, (Rhizines), which can anchor themselves (and sometimes etch through) roof coats after a 5-10 year period. Water blasting at high pressure will remove the oxidised surface of paint. Water blasters with low pressures may not be able to remove all the oxidised paint, which can compromise the bond between the base coats and the roof. This will reduce the life of the roof paint.

Commercial Hose, Fittings, and Attachments

High Pressure Hose

The 2 wire waterblasting hose is perfect for commercial building cleaning. The wire that runs through the hose is designed to be durable and withstand being driven over by large commercial vehicles. It will also minimise blowouts.
Auckland premium painters prefers to use 3 x 30 metre-long lengths. You can get a lot of distance without moving your unit around.
Only the weight of the 2 wire hose can make it more difficult to move and handle around a building wash site. Some operators will use just one wire and change it more often, or use a single length of one wire hose. This takes some weight off and makes working easier.
The 1 wire hose, due to its lighter weight and ease of handling when washing buildings suspended from the air, is better suited for abseiling.


Fittings are the link between the various components of the building wash, soft wash, water blasting and spraying unit. The importance of good fittings and O rings is crucial for the entire setup. All connections, from the tap to the tank, to the pump, high-pressure hose, trigger, and nozzle, should be in good working order. If the O rings or fittings are worn out, they will leak wastewater and chemicals. The drop in pressure will also affect the pump and venturi.

Commercial Triggers & Lances

A wide range of triggers and lances are essential for efficient and effective cleaning. The shorter lances, from 50mm up to 500mm, are ideal for cleaning tight spaces like between buildings, fences close to buildings and inside balconies. A short lance, in combination with the correct pressure, nozzle, and low flow, will make it easier to wash from a ladder.
The medium lances are ideal for roof and building washing. They range from 800mm up to 1.2m. The lances have a bend just before the tip of the nozzle. This bend is useful at times, but it can be very strenuous on your body and cause “kick” every time you pull the trigger. To eliminate kicks and save, use straight lances without any bend. Washing at high pressure or flow.
The use of long lances between 1.5m and 2m is ideal when washing soft buildings that are 1 to 3 stories high. This extra meter allows you to reach more spots and work safely from the ground. The longer lance is also useful for soft-washing large roofs. With the longer lance, you can clean more area per stroke. These lances must not bend at the end if you are using high pressure or high flow to wash.
The 300mm-500mm extension lances are great attachments that fit into the quick connect nozzle and allow you to extend any lance. This extra length will help you to maintain a better posture while washing commercial roofs, and prevent injury.

Ceramic Nozzles

Ceramic nozzles of high quality will help to wash by providing an even pressure on the water stream that exits the nozzle. Metal nozzles with high pressure at the edges can make it difficult to achieve good results in building washing.

Nozzle guide

You’ll need a variety of nozzles to wash a building. The black nozzle can be used to add soft wash chemicals by opening a Venturi. Venturis are typically mixed down to around 10:1 once fully opened. This nozzle has a 400-size and a 40 or 50 degree angle.

The white nozzles work well for rinsing or sweeping. These nozzles are versatile, as they can be used for both soft washing and water blasting. The water is sprayed at a 40 degree angle, which quickly spreads out the pressure once it leaves the tip. This is great for reducing pressure when soft-washing a commercial building or roof. Dropping the throttle on your water blaster will give you even softer results for soft washing buildings that can’t afford to have water enter.

The next angle below a white nozzle is a green nozzle. Green nozzles are angled at 25 degrees and concentrate more pressure in one area. This is a good water blasting spray nozzle, which still covers the ground well.

Yellow nozzles have a 15 degree angle. They are useful for cleaning up moss between paving stone and around the edges of garden paths. They will allow you to reach higher on a building than the white and green nozzles can.

The red nozzle is also known as a pencil nozzle. This is a powerful nozzle that will change your approach to building cleaning. The red nozzle has a long reach and a powerful force that will allow you to work faster when cleaning buildings. This nozzle must be used with caution as any mishaps can cause costly damage to the building surface.

Turbo Nozzles

When used correctly, turbo nozzles can be a great tool for surface preparation. This nozzle is designed to clean surfaces with power. It should only be used for roofs that are in good shape and have a substrate that can hold paint. When used to clean surfaces like tarseal, wooden fences or tarseal, this nozzle leaves circular lines.

Whirlaways/ Surface Cleaners

When you have a water blaster with a pump, Whirlaways can be incredibly useful for cleaning large concrete areas. It is great for car parks and ramps. Sometimes flat roofs can be washed with it. If you have a pump that can deliver 30 litres per minute, then you should be able wash 150 square metres per hour if there is good drainage at the site.

Window Cleaning Equipment

When building washing or window washing, investing in high-quality window cleaning equipment can help you reach hard-to-reach areas. You will also be able to complete the work at a higher standard. The best equipment to use for this is a mop and blades that have elbow/pivoting head, as well as telescopic extensions. Auckland premium painters prefer Sorbo’s window cleaning equipment.

Carbon Fibre Water Fed Poles

These lightweight water-fed poles are perfect for washing the tall surfaces of aluminium or glass building materials, cladding and other building materials that can show spots. The poles are available in a variety of sizes, but can reach up to 18m for window and building washing on buildings with 4 to 5 stories. When used in conjunction with purified/deionised water filters with resin, you will get a better result. You’ll see less spots and have a more shinier finish.

Licenses and training for operators

The industry of building cleaning and water blasting is unregulated. Water blasting and building washing are not regulated by any formal training, unit standards or code of conduct. It takes at least 6 months to develop the necessary skills to safely and effectively wash buildings. You also need to be willing to put in the effort to achieve a high level of work. If you want to expand your building wash business. It is important to develop your own procedures that outline the precise way surfaces are cleaned or prepared, and the unit standards your employees or contractors must follow in order to become competent building wash operators. To ensure safety and awareness, your building wash operators or staff should complete formal training.

Height and Harness Course for Site Safety

You will find that you have to work from heights when cleaning buildings. This course will give you the knowledge and skills to keep yourself and your team as safe as possible.

Site Safe’s heights and harness training course covers the importance of minimizing or eliminating all risk involved in working at heights, as well as the basics of rope and harness and fall arrest systems.
This course is designed for the construction industry. However, it contains many useful tips that can be put to use when cleaning commercial buildings. The Site Safe Passports you receive upon completion of this course are valid for you and your team to wash commercial construction sites.

License for Elevated Work Platform

An EWP is the most efficient way to wash commercial buildings. It is important to be prepared. The training course should include a variety of EWP. It takes some experience to know which EWP is best for a particular building type. Access equipment rental companies can usually give good advice about which access equipment is best for a particular situation. Budget for this when preparing your quotes and proposals.

First Aid Course

If an accident occurs on your site, or nearby, having your operators trained in basic first aid is the best way to respond.

Chemical Use

To achieve great results in building cleaning, it is important to understand the specific uses of chemicals and how they can be used.

Building Washing Chemicals

You should use different chemicals for cleaning your building depending on the situation. For heavy moulds and lichen, a combination of sodium hypochlorite with a surfactant or soaping agent is the best solution. When it comes to road dust and diesel dust, Soft Wash or Trans Wash is the best option.

Commercial Roof Treatments

The active ingredient of moss and mold treatments such as Wet and Forget is Quaternary Ammonium chloride. This product is very effective in removing certain types of mould from surfaces like paths and roofs. This cleaning method’s effectiveness is dependent on a number of variables, including the time of application, the type of organic material being cleaned, the weather, the strength of the solution, the shade surrounding the area to be treated, the organic matter or dampness within the treated area, and the pitch of the roofs. You need to talk to someone with years of experience to get the best idea on how to clean an area using a particular treatment.
Quat, when used at the correct strength, has a bonding property to molecules. This means that it can attach itself to surfaces for as long as 2 or 3 years. Quat is not suitable for certain applications. Consult a professional prior to using this method.

Building Wash Guide by Type

Light Commercial Building Cleaning / 2 to 3-Story Building Cleaning

“The semi-commercial building or small apartment blocks are very similar to house washing. You should be able to transfer your skills from residential house cleaning to these types of buildings if you are familiar with them. The cladding and access will vary, but the soft-washing methods are usually the same. Look out for parapet walls, dividing walls over rooflines (often overlooked or put into the ‘too hard’ basket because it requires roof access), and lichen or mold on top of flashings. When in need of expertise, rely on Your Trusted Exterior House Wash in Auckland for guidance and support.”

Clean the cladding according to any cleaning instructions. Purified/deionised water filtering can help minimise window water spots.
The right equipment or extension is essential if you need to remove stubborn mould or lichen from high-rise walls.
If you’re dealing with a block of apartments or units, make sure that all tenants have been informed of the washing to prevent any inconveniences and keep disruptions to a minimum.
It is helpful to share the water usage between the units when cleaning the building. This way, one tenant won’t be charged for the entire apartment.

Large Commercial Building Washing/2000 to 30,000 Sqm Building and Roof Washing

The key to successfully washing very large commercial structures is to have the right equipment, the correct water flow and the appropriate manpower. The commercial building wash equipment described in Section 2 should be used.
It is important to work together on large sites to ensure everyone’s safety and health. It is often helpful to have a standpipe for a fire hydrant, as many sites do not have outside taps or enough water to clean a roof or large building.
All surfaces should again be assessed to determine the type of dirt, mould, or deterioration. This will allow you to implement the best cleaning method and manage client expectations accordingly.
A clear plan, and the use of the right cleaning method at the beginning will ensure a good result. It will also reduce the need for touch-ups. To speed up roof and large building washing, it is important to use a systematic and methodical approach.

Window and Retail Building Cleaning

The key to cleaning retail sites is planning. This includes building washing around CBD and in the CBD. The sites require extensive glass cleaning, usually at times that are convenient for the client. For the duration of cleaning, automatic sliding glass doors must be locked. You should schedule cleaning or access at times that are convenient to the client/tenant. Access equipment or traffic control may be required for glass canopies. Cleaning concrete and bin areas is another regular task in the city. Make sure you use strong degreasers to sanitise the dirty areas such as the loading bay, back entrance or bins.

Washing School Buildings

You can wash anything from small modular classrooms up to large sports gymnasiums or modern school structures of up to 15,000 sq. m. It is possible to encounter historic buildings such as chapels and halls. You will achieve great results by being knowledgeable and understanding the requirements for cleaning different materials, cladding and school buildings.
Contractors who work on school grounds are required to have health and safety policies in place, and any employees or building washing contractors must be police-checked. It is best to work on school buildings during holidays, when the school is not in session. Work with the school to fit into their budget, and provide long-term plans that will reduce the overall maintenance costs and increase the longevity of surfaces around the school buildings.
Other common school tasks include sweeping up, cleaning concrete and gutters.
If the school uses tank water, check the tank level and disconnect the tank if you are washing the roofs or the walls of the building above the roof line.

Abseil High Rise Building Washing

To wash a building with ropes, you need to have the right training and safety plans for your site. When abseiling building washing, certified abseil-rated anchor points are required on roofs or rigging to solid structures. The methods of window and building washing vary according to the needs of each client. Abseil building cleaners need to know the difference between water blasting, soft washing, and pre paint washing.
Abseiling can be used to access a building to carry out a variety of tasks, such as repairs, maintenance, signage installation, painting, and sign-painting.

Washing Building Sites

You must be flexible and adaptable to the other workers on site to finish your exterior cleaning job.
Make sure you are familiar with the site, the work that is being done and the PPE and health and safety requirements.
If required, you should receive a ticket to work with an EWP. You will need a Site Safe Passport in most cases to do any washing on site.
Building washing is a necessary task on a construction site. Be sure to consider any spraying towards public areas, as well as where the runoff water is going to drain. There are many different ways to clean a building site. Soft washing and low pressure for new cladding etc

Building Washing of Historic Buildings & Iconic Buildings

You need to be an expert when it comes to cleaning historic buildings. You should know the best way to wash a house or building, how to avoid water ingress, and how to do a soft wash (as well as what materials you shouldn’t soft-wash). You should be able to distinguish between a variety of historic materials such as stone, bricks, copper, plaster and concrete, and know how to treat them accordingly.
This will help you to communicate any issues / stains / degradation / wood rot & bubbling paint etc. back to the client to manage realistic expectations. You can then communicate to your client any problems, stains, degradations, wood rot or bubbling paint. You can also offer minor repairs on the spot, especially if you have access to the equipment to wash down the building.
To get close to your work and remove any marks or damage, you will need the right access equipment or an experienced building wash operator. Soft chem cleaning is ideal for painted surfaces. However, it can cause problems later on, when the building wash has been completed, and can worsen efflorescence.

Skylights: How to Clean Them

When washing a building, commercial skylight cleaning should be done in a measured and gentle manner. The fibres of old fibreglass skylights can hold on to mould. You can remove any remaining mould by washing with 1000psi and less after applying a mix of sodium hypochlorite. New skylights have a much lower fibre content and are more porous, making them easier to clean. This is especially true if you regularly wash your building. You should never walk on commercial skylights because they are usually brittle. When washing skylights, it is best to use a rope and harness. This is especially true if the mesh wire is not underneath.

Cleaning Aluminium Cladding and Alucobond Cladding

It is better to think of washing buildings covered in Alucobond or aluminium as window cleaning. Manufacturers’ specifications typically call for a weak/diluted building soap to be used, followed by a soft mop or sponge and then rinsing off. The best results are achieved by using soft brush water-fed poles and deionised/purified water systems. Other chemicals and high-pressure cleaning can cause damage or void warranties.


You will come across oxidisation when it comes to washing buildings. You will become a more effective building washer if you understand oxidisation.

What is oxidisation?

Oxidisation occurs naturally when materials/compounds react over time and breakdown to release oxygen and electrons. It can take anywhere between 3 and 10 years for a coating to reach its end of life, depending on the circumstances and quality of the product.
This means that the coatings are literally dissolving due to constant contact with the environment. There is no way to fix the problem. The coating’s integrity has been compromised.

Tests for oxidation of paints and coatings

Once oxidized, paint and coated surfaces will look dull and chalky (especially darker-coloured coatings or buildings). Customers often think that this is dust or dirt, which can be cleaned. Unfortunately, it is not always the case. You can wipe the coating off with a rag, or even your finger. The residue will come off under a little pressure. This is much easier to see on surfaces with darker colours. You will need to search harder for oxidisation on lighter coloured surfaces.

Cleaning Oxidised Surfaces

It is important to consider the end result that the client wants when washing oxidised surfaces. Do they want to paint it or just have it look clean? Cleaning dark oxidised surfaces is unlikely to achieve the desired results. The dark surface will look great when wet, but after drying out the patches are obvious. When washing to prepare for painting, you should use high pressure to remove any oxidation. This will give the paint a better surface to adhere to. Paint that is painted over oxidised paint can shorten the life of a new coat by several years. You will need between 3500 and 4500 psi for a good pre-paint wash.

Leave a Reply

Your email address will not be published. Required fields are marked *