The Science Behind Mould, Mildew & Algae – Why Your Home Needs Regular Cleaning
Understanding the Growth of Mould, Mildew & Algae
Your home’s exterior is constantly exposed to the elements, making it a prime target for mould, mildew, and algae growth. These organisms don’t just make your home look dirty—they can cause structural damage, health issues, and costly repairs if left untreated!
So, what causes these unsightly invaders to take over, and how can regular exterior cleaning keep your home protected? Let’s break it down.
Mould & mildew on a home’s exterior causes a significant health risk and decreases curb-side appeal
What Are Mould, Mildew & Algae?
Mould: The Silent Destroyer
Mould is a fungus that thrives in moist, shaded areas with little airflow. It spreads through microscopic spores that float in the air and attach to surfaces. Left untreated, this can be particularly in the moist tropical environment of the Sunshine Coast
Common areas: Siding, wooden decks, shaded driveways and roofs
Effects: Causes wood rot, deteriorates paint, and contributes to respiratory issues
Appearance: Black, green or brown fuzzy patches
Mildew: The Less Harmful Cousin of Mould
Mildew is another type of fungus, but it’s generally less aggressive than mould. While it won’t cause major structural damage, it can still stain surfaces and create unhealthy indoor conditions.
Common areas: Roofs, painted walls, tiles and humid outdoor spaces
Effects: Discoloration, musty odors and minor surface deterioration
Appearance: White, gray or yellow powdery growth
Algae: The Slippery Culprit
Unlike mould and mildew, algae is a plant-like organism that thrives in damp, humid conditions. It doesn’t penetrate surfaces like mould does, but it will create a slippery, hazardous film on driveways, patios and stairs.
Common areas: Concrete, pavers, decks and outdoor furniture
Effects: Slippery surfaces, green stains and water retention
Appearance: Green, brown or black slimy patches
Why Does Mould, Mildew & Algae Grow on Your Home?
There are a few key factors that contribute to the growth of these unwanted organisms:
1. Moisture & Humidity
Excess moisture from rain, high humidity or water leaks creates the perfect environment for mould and mildew to thrive. Areas that don’t get much sunlight (such as the southern side of your home) are at even greater risk.
2. Organic Matter & Dirt Buildup
Algae, mould and mildew feed on organic material found in dirt, dust, pollen and other natural debris. If your home’s exterior isn’t cleaned regularly, these contaminants build up and encourage further growth.
3. Poor Drainage & Standing Water
Blocked gutters, clogged drains and improperly sloped surfaces allow water to pool, creating an ideal environment for mould and mildew.
4. Lack of Sunlight
Shady areas, such as under trees, around fences or in covered patios retain more moisture and provide less ventilation, making them a prime spot for mould and algae to take hold.
The Dangers of Ignoring Mould, Mildew & Algae Growth
If left untreated, these organisms can cause significant problems for both your home and your health.
1. Structural Damage & Expensive Repairs
Mould breaks down wood, paint, and roofing materials, leading to costly replacements.
Algae and mildew create slippery surfaces, increasing the risk of falls and injuries.
Unchecked mould growth can spread indoors, affecting walls and insulation.
2. Health Risks for You & Your Family
Mould spores trigger allergies, asthma and respiratory issues.
Prolonged exposure to mildew can cause headaches, fatigue and sinus infections.
3. Decreased Curb Appeal & Property Value
A home covered in green and black streaks looks neglected. This can:
Lower your home’s perceived value if you’re trying to sell.
Create a bad first impression for visitors or potential buyers.
The Solution: Regular Exterior Cleaning
The good news? Regular cleaning can prevent all of these issues before they start!
Pressure cleaning for Hard Surfaces
For driveways, patios and concrete surfaces, pressure cleaning is the most effective way to remove algae and mildew. A high-pressure water stream blasts away grime, restoring the surface’s original look and preventing slips and falls.
Soft Washing for Delicate Surfaces
House exteriors, roofs and wooden decks require a gentler approach. Soft washing uses low-pressure water and eco-friendly cleaning solutions to kill mould and algae at the root without damaging your home’s surfaces.
How Often Should You Clean?
House Exterior: Once a year (more often in humid climates such as Noosa and the Sunshine Coast)
Driveways & Paths: Every 6-12 months
Decks & Fences: Annually, or more frequently if shaded
Why Choose ProClean Noosa?
At ProClean Noosa, we specialise in both pressure washing and soft washing, ensuring the right cleaning method for your home. Our team uses the most effective cleaning solutions to remove mould, mildew and algae safely and effectively.
✔ Extend the life of your home’s exterior
✔ Protect your family’s health
✔ Improve curb appeal & property value
✔ Prevent costly repairs