Mould on the exterior of your home is a common issue across Auckland. With high humidity, frequent rainfall, and shaded areas, mould and algae can quickly grow on walls, cladding, and outdoor surfaces. If left untreated, mould not only affects the appearance of your home but can also damage paintwork and building materials over time.
This guide explains how to remove mould safely, what causes it, and when it’s best to call in professionals.
If your home is heavily affected, you can also learn more about professional house washing services here:
https://www.metrowaterblasting.co.nz/house-wash-auckland/
Why Mould Grows on Houses in Auckland
Auckland’s climate creates ideal conditions for mould growth.
The main causes include:
• High humidity levels
• Frequent rainfall
• Shaded areas with limited sunlight
• Organic buildup such as dirt and dust
• Poor airflow around exterior surfaces
Mould typically appears on the south-facing side of homes or areas that stay damp for long periods.
What Mould Looks Like on Exterior Surfaces
Mould can appear in several forms depending on the surface and environment.
Common signs include:
• Black or dark staining on walls
• Green algae buildup on cladding
• Patchy or streaky discolouration
• Slippery surfaces on decks and paths
These stains can worsen over time if not treated properly.
Can You Remove Mould Yourself?
Yes, light mould buildup can be treated with DIY methods. However, results depend on the severity and type of surface.
For small areas, you can try:
• Soft washing with a mild cleaning solution
• Gentle scrubbing with a soft brush
• Rinsing with low-pressure water
⚠️ Avoid using high-pressure water blasting on house exteriors, as this can damage paint and force water into walls.
DIY Mould Removal Methods
1. Use a Cleaning Solution
A mild cleaning solution can help break down mould and algae.
Apply the solution evenly across affected areas and allow it to sit for several minutes before rinsing.
2. Gentle Scrubbing
For stubborn areas, use a soft brush to gently remove buildup.
Avoid aggressive scrubbing, as this can damage surfaces.
3. Low-Pressure Rinse
Rinse the surface using a garden hose or low-pressure setting.
This removes loosened dirt and mould safely.
Why DIY Cleaning Doesn’t Always Work
While DIY methods can help with light mould, they often fail to remove deeper contamination.
Common issues include:
• Mould returning quickly
• Uneven cleaning results
• Damage from incorrect methods
• Incomplete removal of organic growth
Professional cleaning treats mould at the root and provides longer-lasting results.
Professional Soft Wash House Washing
For best results, mould should be removed using a soft wash system.
This involves:
• Low-pressure application
• Specialised cleaning solutions
• Safe treatment of surfaces
• Complete removal of mould and algae
Soft washing kills mould spores and helps prevent regrowth.
👉 Learn more about professional house washing:
https://www.metrowaterblasting.co.nz/house-wash-auckland/
Areas of the House Most Affected by Mould
Mould tends to grow in specific areas of a property.
These include:
• South-facing walls
• Under eaves and soffits
• Around gutters and downpipes
• Shaded areas behind trees
• Exterior cladding and weatherboards
Regular cleaning helps prevent buildup in these areas.
How to Prevent Mould from Coming Back
After cleaning, there are steps you can take to reduce future growth.
Improve Sunlight Exposure
Trim trees and remove shading where possible.
Clean Regularly
Annual house washing helps prevent buildup.
Maintain Gutters
Blocked gutters contribute to moisture problems.
👉 Gutter cleaning services:
https://www.metrowaterblasting.co.nz/gutter-cleaning-auckland/
Treat Roof Moss
Roof debris often contributes to mould buildup.
👉 Roof cleaning services:
https://www.metrowaterblasting.co.nz/roof-cleaning-auckland/
How Often Should You Remove Mould?
Most homes in Auckland should be cleaned:
• Once per year
• More frequently in shaded areas
• After winter for best results
Regular maintenance prevents mould from becoming deeply embedded.
DIY vs Professional Cleaning – What’s Better?
| DIY Cleaning | Professional Cleaning |
|---|---|
| Temporary results | Long-lasting results |
| Limited effectiveness | Full mould removal |
| Risk of damage | Safe and controlled |
| Time-consuming | Fast and efficient |
For heavily affected homes, professional cleaning is the safest and most effective option.
When to Call a Professional
You should consider professional cleaning if:
• Mould covers large areas
• Stains are deeply embedded
• DIY methods are not working
• You want long-lasting results
• You want to avoid damage
Professional Mould Removal Auckland
Metro Water Blasting provides professional house washing services across Auckland using safe and effective soft wash methods.
Our team specialises in removing mould, algae, and grime from exterior surfaces while protecting your home.
We service:
North Shore
West Auckland
East Auckland
South Auckland
Central Auckland
If your home exterior is covered in mould, professional cleaning can restore its appearance quickly and safely.
Request a quote here:
https://www.metrowaterblasting.co.nz/house-wash-auckland/
Request a Quote Today
Mould buildup can damage your home and reduce its appearance if left untreated.
Metro Water Blasting provides expert mould removal and house washing services across Auckland.
Call 0800 997 997 or request a quote through our website today.