Exterior Surface Contaminants Explained: What They Are and How to Get Rid of Them
Outdoor surfaces are constantly exposed to the elements—and over time, they attract a range of surface contaminants that not only affect how your property looks, but also how long those surfaces last. From mould and algae to lichen, grime, oil stains, and rust, these build-ups can cause staining, surface degradation, and safety risks if not dealt with correctly.
On the Central Coast, where humidity, tree coverage, and coastal conditions all contribute to organic growth and residue, regular cleaning becomes more than just cosmetic—it’s essential maintenance.
Pressure cleaning and soft washing are two of the most effective ways to remove these contaminants safely and thoroughly. At Glason High Pressure Cleaning, we use both methods—alongside targeted treatments like biocide—to restore and protect homes, businesses, and strata properties across the region.
In this blog post, we’ll cover the most common types of exterior contaminants, how they form, and why professional exterior cleaning is the best way to keep your property looking its best.
The Usual Suspects: What’s Really On Your Surfaces
When it comes to exterior surface contaminants, most people think of mould or dirt—but there’s usually much more hiding in plain sight. These are the most common offenders found on homes, driveways, decks, and roofs across the Central Coast:
- Mould & Mildew:
Fungal growth caused by moisture and humidity. Mould penetrates deep, while mildew stays closer to the surface—both cause staining and surface damage if left untreated. - Algae:
Common in shaded, damp areas. Algae creates a slippery layer that discolours concrete, timber, and tiles, and becomes dangerous underfoot when wet. - Lichen:
A stubborn combination of fungus and algae that bonds to surfaces like concrete, stone, and tile. Lichen is slow-growing but very tough to remove without the right treatment. - Organic Grime:
Built-up dirt, leaves, bird droppings, and decomposing matter. It traps moisture, encourages mould growth, and gradually breaks down the surfaces it settles on.
Each of these contaminants behaves differently—but all of them share one thing in common: they won’t go away with a basic hose-off, and the longer they’re left untreated, the worse the damage becomes.
Emerging Concerns: Rust Stains, Oil Spills, and More
While mould and algae are common, some surface contaminants are less obvious—but just as damaging. Rust stains and oil spills in particular can leave permanent marks if not treated correctly.
- Rust Stains:
These often come from metal fixtures, roof runoff, or irrigation systems with iron content in the water. Once rust sets into concrete, brick, or render, it leaves behind a deep orange-brown stain that’s nearly impossible to remove without specialist treatment. Abrasive scrubbing often makes the problem worse.
- Oil Spills and Grease Marks:
Driveways, garages, and parking areas frequently suffer from engine oil or cooking grease. These substances seep into porous surfaces like concrete and pavers, causing long-term staining and attracting more dirt and grime.
- Paint Overspray, Mineral Deposits, and Sap:
Other less common issues—like construction residue, calcium deposits from hard water, or sticky tree sap—can also compromise your property’s surfaces if not properly addressed.
These contaminants require different treatment methods depending on the surface type and how long they’ve been sitting. In most cases, professional pressure cleaning combined with the correct chemical solution is the only way to remove them safely and effectively.
Why Pressure Cleaning Works
Exterior surface contaminants cling tightly to materials like concrete, timber, brick, and render. In many cases, they penetrate beneath the surface—making regular rinsing or scrubbing ineffective. That’s where pressure cleaning makes all the difference.
Using high-pressure or soft washing techniques, Glason removes built-up grime, biological growth, and deep-set stains without damaging the underlying surface. Each approach is chosen based on the type of material and the contaminant involved.
- High Pressure Cleaning:
Ideal for hard surfaces like concrete, pavers, and exposed brick. This method lifts stubborn build-up, oil stains, rust streaks, and embedded grime. - Soft Washing:
Used for painted finishes, timber, and delicate areas. We combine low-pressure application with specialised cleaning agents—including biocide—to kill contaminants at the source without harming the surface.
The result? A thorough clean that doesn’t just improve the look of your property—but also protects it from further deterioration.
"Trusted by Central Coast locals for 30+ years".
Why Choose Glason for Surface Contaminant Removal
Not all pressure cleaning is the same. At Glason, we combine over 30 years of experience with the right equipment, techniques, and treatments to safely and effectively deal with all kinds of exterior surface contaminants—without causing damage to your property.
- Tailored Approach:
We assess every surface and choose the right method—whether that’s high pressure, soft washing, or a combination of both.
- Biocide Treatment:
For mould, algae, lichen, and organic grime, we apply a professional-grade biocide that kills growth at the root and helps prevent regrowth.
- Attention to Detail:
We don’t just blast surfaces and leave. Our process is measured, safe, and thorough—restoring your property while extending the life of your exterior surfaces.
- Servicing the Central Coast:
Based locally, we understand the climate conditions that lead to build-up and tailor our cleaning methods to suit properties across the region.
From one-off cleans to scheduled maintenance, Glason High Pressure Cleaning is trusted across the Central Coast for delivering visible results that last.
Restore and Protect Your Surfaces – Book a Professional Clean Today
Organic grime, mould, lichen, rust stains, and oil spills aren’t just unsightly—they damage surfaces over time. The longer they’re left, the harder and more costly they are to remove.
Glason High Pressure Cleaning delivers safe, effective solutions across the Central Coast using the right equipment, expert techniques, and targeted treatments like biocide to restore and protect your outdoor areas.
Not sure what’s on your surfaces?
