Published on: July 17th, 2026
By Nathan Hall, Director at Chemwash Rotorua
Thinking about giving the outside of your house a clean? You might be wondering whether it’s worth doing it yourself, or calling in the professionals.
The honest answer is that DIY house washing can be fine for small, easily accessible areas, as long as you know what you’re doing. But when it comes to a full house wash, hard-to-reach areas, delicate surfaces, mould, lichen, cobwebs, or anything involving ladders, a professional house wash is usually the safer and more effective option.
At Chemwash Rotorua, we use a specialised low-pressure cleaning system designed to clean exterior surfaces properly without the harsh force of traditional water blasting. That means a great result without putting unnecessary pressure on your paint, cladding, windows, roof, or other exterior surfaces.
So, before you give up your weekend and drag out the water blaster, here’s what to think about.
DIY vs Professional House Washing: Quick Comparison
| DIY House Washing | Professional Chemwash House Washing | |
|---|---|---|
| Best For | Small touch-ups with gentle equipment | Full house washing, high areas, and stubborn build-up |
| Main Advantages | Lower upfront cost | Better results, less hassle, and surface-specific methods |
| Main Risks | Damage, streaking, missed areas, or safety issues | Vastly reduced risk with trained operators and correct equipment |
| Equipment | Hose, soft brush and suitable cleaner | Specialist low-pressure cleaning equipment |
| Time Involved | Can often take longer than expected | Two minutes to request a quote, then we handle everything for you |
When DIY House Washing Can Make Sense
DIY house washing is not always a bad idea. For a small, ground-level area with light dirt, a simple tidy-up can be manageable.
A soft brush, garden hose and a bit of patience can go a long way if you are only cleaning a small section of wall, or a spot that has picked up a bit of dust or grime.
DIY can be suitable when:
- You are not relying on high-pressure water blasting.
- The area is small and easy to reach.
- You do not need to use a ladder.
- The surface is strong and in good condition.
- You are using gentle products.
- You are not dealing with a lot of mould, lichen, or stains.
The trouble usually starts when the job gets bigger, higher, more stubborn or more delicate than expected. That’s when a quick Saturday job can turn into a frustrating, messy, and potentially risky one.
Where DIY House Washing Can Go Wrong
Problems with DIY house washing often arise from using high pressure water blasting, incorrect safety equipment or practices, or the wrong cleaning products. Remember that a house exterior is not one single surface. You might be dealing with painted weatherboards, plaster, brick, aluminium joinery, windows, and more, all in one job. Each surface needs the right approach.
1. High Pressure Water Blasting
One of the biggest risks with DIY house washing is using an aggressive water blaster too. High pressure might seem like the fastest way to remove grime, but it can also:
- Lift or strip paint
- Force water behind cladding
- Damage window seals
- Mark plaster or softer surfaces
- Splinter timber
- Remove protective coatings
- Leave streaks or uneven patches
At the end of the day, clean should improve your home’s appearance, not create more repair work.
2. Awkward Access, Ladders, and Wet Surfaces
Cleaning the outside of a house often means working around slippery paths, wet decks, awkward corners, roofs, and high walls.
Once ladders get involved, the job becomes a lot more serious.
Two-storey homes, steep sections, high windows, and hard-to-reach areas are best handled with the right gear and experience. Even if you are confident on a ladder, it only takes one slip or awkward movement for things to go wrong.
At Chemwash Rotorua, we deal with tricky access and awkward exterior cleaning jobs every day. That means you can stay safely on the ground while we take care of the hard-to-reach areas.
3. Store-Bought Cleaners Are Not Always the Right Fit
Another common issue with DIY house washing is using the wrong cleaning product.
Some cleaners are too harsh. Some are too weak. Some are not suited to the surface being cleaned. Others may leave marks, streaks or residue if they are not applied or rinsed correctly.
There is also the question of what you are trying to remove. Dirt, mould, algae, lichen, cobwebs, pollen and general grime all behave differently. Blasting the surface may make it look cleaner for a short time, but it may not properly deal with the underlying build-up.
Professional house washing is not just about spraying water at a wall. It is about knowing which method is right for the surface and the condition of the property.
Why Chemwash Uses Low-Pressure Cleaning
Chemwash does not rely on blasting dirt off with brute force.
Our specialised gentle cleaning system first uses biodegradable cleaning products rather than harsh chemicals. In fact, we like to say that there’s nothing in our detergents that you won’t find under the kitchen sink!
We then use low water pressure to ease away grime, mould, lichen and other exterior build-up. This system is designed to get a proper clean without the harsh impact of traditional high-pressure water blasting. That makes it a great option for any home, but especially those where surfaces need a bit of care.
It is a smarter way to clean, because the goal is not just to make the house look better on the day. It is to clean it properly while helping protect the condition of the surface.
Is DIY Actually Cheaper?
DIY house washing can seem cheaper at first. After all, a bottle of cleaner from the hardware store will not cost much. But the real cost can include more than just products.
You may also need to think about:
- Equipment hire or purchase
- Your time
- The quality of the result
- The risk of damage
- The cost of fixing any mistakes
A DIY full house wash can take much longer than expected, especially if the property is large, awkward, two storeys, or has heavy build-up.
With Chemwash Rotorua, you can request a free, no-obligation quote before making that decision. That gives you a clear idea of what is involved and whether professional cleaning is the right option for your place.
Which Option Is Right for You?
DIY may be fine if you are cleaning a small, low, easy-to-reach area and the surface is in good condition.
But it is worth calling Chemwash Rotorua if:
- The whole house needs washing
- Your home is two storeys
- There are awkward or high areas
- You are dealing with mould, lichen, algae or heavy grime
- You are worried about damaging paint or cladding
- You want windows, gutters, paths, deck cleaning or roof treatment included
- You are preparing the surface for painting
- You do not want to spend your weekend cleaning the house
- You want the job done properly by experienced local operators
If you are not sure, the easiest option is to get a quote. We can take a look, explain what we recommend, and give you clear advice before you decide.
House Washing Advice for Rotorua Homes
Rotorua homes can deal with plenty of exterior build-up throughout the year. Shaded areas, damp weather, nearby trees, pollen, cobwebs, mould and lichen can all leave your place looking tired.
A regular house wash helps keep your home looking sharp and well cared for. It can also make a big difference before summer entertaining, before selling, before painting, or simply when the exterior is starting to look a bit grubby.
Spring and early summer are popular times to book, but exterior maintenance is useful all year round. Autumn and winter can also be a good time to deal with gutters, slippery paths, moss, mould and roof treatments.
The best timing depends on your property, the surfaces involved, and how quickly build-up returns. If you are unsure, our local team can give practical advice based on your home.
What’s Included in a Professional House Wash?
Every property is different, but generally a Chemwash Rotorua house washing quote may include exterior wall washing and removal of general grime, mould and organic build-up using our low-pressure cleaning system.
Depending on your property, we can also quote for other exterior cleaning services, including:
- Window cleaning
- Roof treatments
- Gutter cleaning
- Deck cleaning
- Fence cleaning
- Concrete and path cleaning
- Exterior spider treatments
This means you can deal with more than one job at the same time, instead of trying to tackle everything separately.
Why Choose Chemwash Rotorua?
Chemwash Rotorua is locally owned and operated, backed by New Zealand’s largest exterior cleaning and house washing company.
We have been helping Rotorua homeowners keep their properties looking great for decades, using a low-pressure cleaning system that is effective, versatile and designed to reduce the risk of surface damage.
You get:
- Local Rotorua exterior cleaning experts
- Years of house washing experience
- Safe, proven cleaning techniques
- Personalised advice for your property
- Great results with safe cleaning techniques
- Free, no-obligation quotes
Whether your place needs a full house wash, a roof treatment, clean gutters, brighter windows, a fresher deck, or a tidy-up before summer, we can help.
DIY Has Its Place, But Know the Risks
In summary, for a full house wash, high areas, delicate surfaces, stubborn mould, lichen, pre-paint preparation, or anything where damage is a concern, professional low-pressure cleaning is usually the safer and smarter option compared to DIY.
A proper house wash should leave your home looking fresh, clean and well cared for, without putting your surfaces at unnecessary risk.
Ready to get your place looking sharp again? Request your free Chemwash Rotorua quote online today.
FAQs
Is DIY house washing safe?
DIY house washing can be safe for small, ground-level areas, and you don’t use a standard water blaster. It becomes riskier when high-pressure equipment, ladders, slippery surfaces, delicate cladding, or the wrong cleaning products are involved.
Is professional house washing worth it?
Yes, professional house washing is usually worth it if you want a full exterior clean, have a two-storey home, are dealing with mould or lichen, or want to reduce the risk of surface damage from high-pressure washing.
Can I water blast my house myself?
You can, but it comes with risks. High-pressure water blasting can damage paint, cladding, timber, seals, windows and other exterior surfaces if it is not done carefully. For most full house washes, a professional low-pressure clean is the safer option.
What is the safest way to wash a house exterior?
For most homes, the safest approach is low-pressure cleaning with the right products for the surface. This helps remove grime and organic build-up without relying on harsh pressure.
Is Chemwash the same as water blasting?
No. Chemwash uses a specialised low-pressure cleaning system rather than traditional high-pressure water blasting. The aim is to clean effectively while reducing the risk of damage to exterior surfaces.
How often should I wash my house in Rotorua?
Generally speaking, results from a Chemwash house wash can last for up to 12 months, however this does depends on your property. Homes surrounded by trees, shade, damp areas or heavy exposure may need cleaning more often.
Can Chemwash clean more than just the outside walls?
Yes. Chemwash Rotorua can clean a wide range of exterior surfaces, including houses, roofs, gutters, concrete, decks, fences and windows. We can also provide exterior spider treatments and pre-paint washing where required.
Should I wash my house before painting?
Yes, a pre-paint wash is usually recommended before painting. It helps remove dirt, grime and build-up so the surface is properly prepared. Chemwash Rotorua can quote for pre-paint washing and advise on the best approach for your property.
Sources & Further Reading
The advice in this article is informed by Chemwash Rotorua’s practical experience, and is also supported by guidance from New Zealand safety authorities and relevant specialists.
- WorkSafe New Zealand – Safe Working with Ladders and Stepladders
WorkSafe recommends choosing the correct ladder for the task, checking that it is in good condition and taking appropriate precautions when working at height. This reinforces the importance of considering access and fall risks before attempting to wash upper storeys, eaves or other elevated areas.
Read WorkSafe’s ladder safety guidance - WorkSafe New Zealand – High-Pressure Water Blasting and Asbestos
WorkSafe warns that high-pressure water blasting can disturb asbestos fibres in roofing or exterior cladding and spread them through the surrounding environment. Homeowners should not water blast materials that contain, or may contain, asbestos.
Read WorkSafe’s asbestos safety alert - James Hardie New Zealand – Cladding Care and Maintenance
James Hardie recommends cleaning several of its fibre-cement cladding products using low-pressure water and a brush. Its care guidance advises against using a water blaster on these cladding systems, demonstrating why the cleaning method should be matched to the specific exterior material.
Read the James Hardie Stria™ Cladding Care and Maintenance Guide - Resene – Exterior Cleaning and Maintenance Guidance
Resene advises that water blasting may damage exterior paint finishes and should not be used on wooden weatherboards, decks or outdoor furniture because the pressure can damage the wood grain and leave the surface rough.
Read Resene’s home maintenance guidance
Cleaning requirements can differ depending on the age, condition, coating and material of your home’s exterior. Always check the care instructions provided by your cladding or paint manufacturer before carrying out DIY house washing.
