Commercial water blasting, window Cleaning and more
Blast Away Guys cleans commercial buildings from single-storey retail blocks to roofs the size of 12 rugby fields. We work across corporate offices, schools, retirement villages, aged care facilities, justice and correctional facilities, airports, council and government buildings, industrial warehouses, and large residential complexes. We have been doing this for 14 years.
The same care that goes into a small commercial premises goes into a multi-storey post-buildwash with 37 other trades still on site. That consistency is what our commercial clients rely on.
Airports, large shopping complexes, multi-tenancy buildings, supermarkets, and any commercial site with a high number of staff and public require a different approach from a straightforward building wash. The sequencing of the work matters as much as the work itself.
On large commercial sites, we start with the entrance. The building is still closed, the street is quiet, and it is the perfect window to get the entry, surrounding concrete, and paving washed and looking sharp before the doors open and the public arrives.
After washing, we apply a slow-release treatment to all concrete and paved surfaces. That treatment continues to work over the next two to three weeks, killing mould spores and extending how long the surface stays clean. It also prevents something that most people do not realise happens after the wash.
treatment andWhen concrete or paving is washed without treatment, streak marks start to appear within two to four weeks. By week four, they are very noticeable. We have seen this happen on commercial streets in Whangarei after another company completed the work, and we have observed it multiple times across different jobs.
There are two things causing it.
The first is differential cleaning. Water blasting cleans to slightly different depths across a surface depending on the pressure and the angle of the wand.
Concrete is porous, with small air pockets throughout the surface. The deeper the cleaning, the more those pores open. As normal foot and vehicle traffic resumes, dirt and grime settle back into those open pores faster than the surrounding areas. The pattern of the wash becomes visible over time.
The second is biological regrowth. Pressure washing removes what is visible, but it does not kill the spores embedded in the surface. Those spores re-establish within weeks. On a surface with uneven porosity from the wash, the regrowth follows the same pattern as the differential cleaning, and the streak marks deepen.
Treatment closes the surface after washing, kills the embedded spores before they can re-establish, and equalises the porosity so there is no differential re-soiling pattern to follow. It is a step a lot of contractors skip. We do not.
After the entrance is done, we move to the sides of the building, starting with whichever elevation gets the most public or pedestrian traffic, and finishing with the back.
The cladding wash follows the same priority sequence. The roof work, which typically means a roof treatmentand gutter clear, is done last.
We will often be doing the roof work during the day, with thousands of shoppers or office staff going about their business underneath us. They would never know we were there.
Why we recommend roof treatment over roof washing for most commercial buildings
After 14 years of treating and washing commercial roofs across Northland and Auckland, we have a clear view on this. For the vast majority of commercial buildings, regular roof treatment is the right approach. We will always tell you when a wash is the better call, but most of the time it is not.
A roof treatment involves applying a concentrated product to the roof surface. It kills lichen, moss, and mould at the root. The rain and sun then gradually break down and remove the dead growth over time. How long that takes depends on several factors: the type and thickness of the growth, how much direct sun the roof receives, and the underlying organism.
Lichen on a well-sunlit roof may clear in a few months. On a roof that stays shaded and damp, it takes longer. Black mould is the most persistent and can take up to 18 months to fully clear, which is why our treatment technique for black mould involves two concentrated applications rather than one.
A roof wash, depending on pitch and difficulty, costs roughly three to four times as much as a treatment. It uses high-pressure water, requires at least two technicians with one harnessed on the roof, and can take anywhere between six and twelve hours, depending on the roof.
And because it does not address the underlying spores, mould, and lichen return faster after a wash than after a treatment. So if, for whatever reason, we are washing a roof, we always apply a treatment straight afterwards to kill the spores and keep the roof clean for longer.
From a single retail store front to a roof the size of 12 rugby fields, the same care goes into every job. We work until it is right. That is the only way we know how.
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All paint manufacturers recommend cleaning exterior paintwork annually in the NZ Building Code and by all paint manufacturers.
Building materials under warranty
In many cases, commercial building materials require regular washing and maintenance to ensure manufacturer warranties remain valid. We can develop a tailored maintenance plan to help ensure your building is cleaned in accordance with warranty requirements and manufacturer recommendations.
Even when materials are no longer under warranty, regular exterior washing still plays an important role in maintaining presentation and preventing the build-up of grime, moss, mould, algae, and environmental contaminants. A clean, well-maintained building creates a positive first impression for customers, visitors, tenants, and staff.
Longer-lasting results
When we clean areas affected by mould, moss, algae, or grime, we do not simply wash and walk away. Where appropriate, we also apply a slow-release treatment designed to target spores and help keep surfaces cleaner for longer.
This approach helps slow regrowth, improves long-term presentation, and maximises the effectiveness of the clean.
Prevention is better than cure
Regular exterior maintenance helps identify minor issues before they become larger and more expensive problems. If we notice areas requiring attention during the wash process, we are happy to advise you and can provide photos and post-wash reporting if requested.
Preventative maintenance can help extend the life of exterior surfaces while keeping your property looking professional year-round.
What is included in your building wash
Our commercial building washing service typically includes exterior wall washing from ground level to the gutter line, as well as joinery, entranceways, alcoves, eaves, exterior gutters, spouting, and downpipes.
Our telescopic soft wash system can safely reach areas up to 15 metres high from the ground, often eliminating the need for elevated work platforms and helping reduce access costs.
heights of up to 15 metres above ground, often eliminating the need for elevated work platforms and reducingany areas requiring attention during the wash process, we are happy to advise you and can provide photos and post-wash reports upon request
reducing anyOur team is trained in commercial site safety procedures and can work around operational requirements to minimise disruption where possible.
We can also establish scheduled maintenance programmes to help keep your property consistently clean year-round.
After 14 years and thousands of jobs across Northland and Auckland, that number says more than we ever could..
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What we have seen over the years
Some of those roofs are the size of 12 rugby fields. The same principle holds at any scale: when treatment is done consistently and correctly, washing becomes unnecessary.
White and light-coloured roofs
Black mouldand lichen growth are significantly more visible on white and pale surfaces than on dark roofs, which can make a building look poorly maintained even when the growth is at an early stage.
There is a practical reason for this beyond appearance.
Light-coloured roofs do not absorb and radiate heat the way dark roofs do. They tend to stay cooler and take longer to dry out after rain, which creates more favourable conditions for mould and lichen to establish.
Dark roofs heat up quickly and dry faster, creating a less hospitable surface for growth.
We treat the roofs of a multi-site business with locations across Northland and Auckland, many of which have white or light-coloured roofs.
Before they began a regular treatment programme with Blast Away Guys, several of those roofs had significant lichen and black mould build-up.
Since moving to annual treatment, those roofs have stayed consistently clean. The underlying environmental conditions have not changed. The regular treatment interrupts the cycle before it takes hold.
When we will recommend a wash instead
A wash is the more appropriate method in those cases.
The second is tiled roofs, particularly older ones. We are cautious about washing tiled roofs because the high pressure can dislodge tiles, which can cause leaks, and in some cases tiles come off the roof entirely and break.
We have not had this happen on our jobs, but we have seen it happen in the industry, and we will not take that risk with an older tiled roof. Treatment isthe safer and more appropriate approach.
The third situation is pre-paint preparation, where the surface needs to be clean before coating. In that case a wash is required regardless. We will always tell you clearly which approach is right for your roof and why.
Post-build washs: how we manage the pressure
Post-build washes are some of the most logistically demanding jobs in commercial cleaning.
The building is not yet open. Multiple trades are still finishing their work.
Everyone is running against the same fixed deadline.
Contracts are in place, and if a trade's scope is not completed to standard, invoices do not get paid. The pressure on site is real.
We have completed post-build washes on major commercial projects in Auckland and Northland, working alongside electricians, builders, painters, security specialists, and other trades all finishing simultaneously.
Coordinating a wash within that environment requires planning, clear communication, and the ability to work steadily when everyone around you isunder pressure.
Commercial post-build wash, Broadway Auckland — 37 trades on site
Case study
A company was originally contracted to perform a post-build wash for a large, multi-level commercial building on Broadway in Auckland.
Broadway is one of the city's busiest pedestrian and traffic corridors, which meant most of the work had to be done at night and in the early morning hours.
The job was scheduled across five days. That company walked off after a day and a half. They found the environment too difficult and frustrating to manage.
Blast Away Guys was brought in.
At peak, there were 37 other trades working on site simultaneously, electricians, builders, painters, security specialists, and others.
Many of whom had already missed their own scheduled deadlines and were under significant pressure.
The trades were working through the night to finish the project.
The street-facing work had to be coordinated around the volume of pedestrians and traffic on one of Auckland's busiest roads.
We managed it like clockwork. A huge part of that was being mindful and respectful of the other trades on site, and maintaining very good, even-keeled communication throughout.
When everyone around you is stressed and behind, that steadiness matters as much as anything else.
Health and safety. We never give it a day off.
Blast Away Guys is committed to the health and safety of our team, our clients, and everyone else on the sites we work on.
Before we begin any site work, we perform hazard identification, WorkSafe NZ notifications where required, site-specific emergency planning, and all relevant documentation. We hold regular safety meetings, audits, and ongoing training across the team.
In 2024, we acquiredearned a SiteWise 100% Gold rating, the highest level for safety, stability, and adherence toearned a SiteWise 100% Gold rating, the highest level for safety, stability, and adherence to a SiteWise 100% Gold rating, which is the highest level for safety, stability, and for following all necessary protocols. We have maintained this for 3 years now.
This matters for commercial clients because it means your procurement or facilities team can pre-qualify us quickly. Our documentation, safety records, and compliance history are available on request.
Before any commercial job begins, we complete a Job Safety Analysis specific to the site. This covers WorkSafe notification requirements, traffic management where needed, spotter placement, access equipment procedures, chemical handling documentation, and timing decisions.
It is all designed to protect your staff, customers, and the public.
For jobs requiring access to machinery on a road or in high-foot-traffic areas, we schedule work at night or in the early hours.
That health and safety discipline is not something we switch on for an audit. It is how we operate on every job, including the ones where nobody is checking.
The environments we work in
Corporate offices and retail buildings
Schools and early childhood centres
and minimalChildren and staff are on site most of the day, which means timing, chemical safety, andminimal disruption are all non-negotiable. We use biodegradable solutions and plan the work around your timetable. We take particular care with gardens, plantings, and outdoor play spaces.
We have a dedicated page for schools and early childhood centres with more details on how we work in these environments.
Retirement villages and aged care facilities
Our equipment is manoeuvred thoughtfully around garden beds, pathways, and outdoor seating areas. We provide full chemical documentation for your records.
Industrial facilities and warehouses
Shopping centres and multi-tenancy buildings
Council, government, and public infrastructure
and community.
We have completed post-build washes on multi-level commercial and council buildings with other trades still on site, working to coordinate schedules and fixed completion dates.
Justice and correctional facilities
Planning and documentation for these jobs is thorough and starts well before we arrive on site.
Airports and transport infrastructure
What we clean on commercial properties
Building exterior washing
Roof cleaning and treatment
After cleaning, we apply a slow-release treatment to inhibit re-growth and extend the time between cleans. For a full explanation of why we recommend treatment over washing for most commercial roofs, see the section above.
Gutter and downpipe clearing
Concrete and hard surface washing
For high-traffic commeffectively remove built-up grime, algae, rubber marks, and stainingercial surfaces, we apply a slow-release treatment after the wash to prevent the differential re-soiling that causes streak marks to appear over the following weeks.
Solar panel cleaning
We clean commercial solar panels using a combination of soft brushing, a gentle water fan attachment, and our water purifying system, which removes calcium and minerals from the water to leave a streak-free, spot-free result.
On any commercial building where both solar panels and a roof are being cleaned, we strongly recommend combining the two services. Mould, moss, and lichen on a roof produce airborne spores that transfer directly to the solar panels and grow back quickly.
Treating the roof at the same time protects the panels and extends the time before they need cleaning again. We can quote both as a single visit.
Window cleaning
No chemicals are used, which is safer for staff and customers. One operator cleans safely from the ground using a lightweight pole reaching up to 10 metres.
For windows above that height we use an elevated work platform operated by certified operators.
Chewing gum removal
Why regular maintenance matters more than people realise
Without it, the warranty is void. Blast Away Guys can develop a maintenance schedule aligned with your specific building materials and manufacturer requirements.
For buildings used by the public, particularly schools, retirement villages, aged care facilities, and health environments, biological growth on surfaces is also a hygiene and compliance consideration. And of course it looks terrible.
Regular cleaning removes the build-up before it becomes a problem.
Why Blast Away Guys
Over the past 14 years, we have completed thousands of commercial cleaning projects ranging from small storefronts and office buildings through to airports, schools, industrial facilities, council properties, justice and correctional facilities, large-scale body corporates, and industrial roofing projects covering areas the size of 12 rugby fields.
Commercial exterior cleaning requires far more than simply turning up with equipment. It requires strong communication, reliable systems, health and safety awareness, careful planning, and the ability to work around operational requirements with minimal disruption.
We are proud to be a verified SiteWise Gold contractor, giving many commercial clients added confidence in contractor compliance and site safety standards.
Many of our commercial customers move onto scheduled maintenance programmes after their initial clean. These programmes help maintain presentation standards year-round while simplifying budgeting and ongoing property maintenance.
One of the reasons many commercial clients continue working with us long term is that we make the process straightforward and easy to manage. Clear communication, reliable scheduling, detailed quoting, and proactive planning help reduce stress and minimise disruption for property managers, facility teams, and business owners.
During business hours, most quotes are returned within one to two hours, and for larger or more complex projects, we are happy to carry out site visits to ensure the scope, access requirements, and pricing accurately reflect the work involved.
Frequently Asked Questions
What types of commercial properties do you clean?
If you are not sure whether your property fits, call us and we will let you know.
Do you work outside of business hours?
How do you manage health and safety on busy commercial sites?
Do you take care around gardens and planted areas?
Can you provide documentation for compliance or building managementrecords?
Do you offer ongoing maintenance plans for commercial properties?
Can you handle large or multi-storey buildings?
Why do you recommend roof treatment over roof washing for commercialbuildings?
In 14 years of treating significant-sized commercial roofs on a regular basis, we have never had to wash a single roof we regularly treat. We will always tell you when a wash is the right call, but for most commercial buildings in good maintenance condition, treatment is the better approach.
Why do streak marks appear on concrete and paving after water blasting?
If you are not sure whether your property fits, call us and we will let you know.
Get a quote for your commercial property
Quotes are returned within one to two hours during business hours.
Get a commercial quote
Or call 027 238 8738 to talk through the job first.
Commercial maintenance plans
Most commercial clients move to a regular maintenance plan after the first job. It simplifies theprocess: one team, consistent pricing locked in for the duration of the agreement, and no need to requote each time. Plans are typically structured as annual or twice-yearly visits, though we can adjust the frequency to suit the building and its environment.
Regular scheduled maintenance also protects your building materials. In many cases, cladding and roofing manufacturers require scheduled cleaning as a condition of their warranty. We can structure a plan around those requirements so the warranty stays valid.
Pricing is fixed for the term of the agreement, which makes budgeting straighforward. Call 027238 8738 or get a quote to discuss what a plan would look like for your property.
