Can Pressure Washing Remove Mold and Mildew?

If you’ve noticed black, green, or gray patches growing on your siding, deck, driveway, or roof, you’re likely dealing with mold or mildew. These unsightly growths not only diminish your home’s curb appeal but can also cause structural damage and health issues if left untreated. One of the most popular solutions homeowners turn to is pressure washing—but does it really remove mold and mildew?

The short answer is yes, pressure washing can remove mold and mildew from many exterior surfaces. However, for long-lasting results and to avoid damage, it’s important to understand the proper technique, the role of cleaning solutions, and when to consider soft washing instead.

Does pressure washing really get rid of mold and mildew—or just blast it around?

How Mold and Mildew Grow

Mold and mildew thrive in damp, shaded environments. Areas like north-facing siding, decks, shaded patios, and places where water pools are particularly vulnerable. Once established, mold and mildew can spread quickly, especially in humid climates, posing a risk to wood, paint, shingles, and even concrete.

Besides being a cosmetic issue, mold and mildew can lead to respiratory problems, allergic reactions, and a musty odor around your property.

How Pressure Washing Helps

Pressure washing is an effective method for physically removing mold and mildew from hard exterior surfaces such as concrete, brick, stone, and vinyl siding. The high-pressure stream blasts away the top layers of organic growth, grime, and dirt, leaving surfaces looking much cleaner.

However, pressure washing alone doesn’t always kill the spores that cause mold and mildew to return. This is where cleaning agents and proper technique become critical.

Cleaning Solutions Matter

To eliminate mold and mildew at the root, most professionals combine pressure washing with mildew- and mold-killing detergents. These specialized cleaners break down the fungal structure, kill the spores, and help prevent regrowth.

Some common cleaning agents used in pressure washing include:

• Sodium hypochlorite (bleach) solutions

• Biodegradable mold-killing detergents

• Vinegar-based cleaners for sensitive areas

The cleaner is typically applied to the surface and allowed to dwell for several minutes before being rinsed away with a pressure washer or soft washer. This combination delivers a deeper, more lasting clean than pressure washing alone.

Pressure Washing vs. Soft Washing

While pressure washing is great for tough surfaces like concrete, it can be too harsh for more delicate materials such as roof shingles, painted wood, and stucco. For these, soft washing is the preferred method. Soft washing uses low pressure (under 500 PSI) along with chemical cleaners to gently remove mold, mildew, and algae without damaging the surface.

If you're dealing with mould on your roof, wood siding, or fence, soft washing is typically the safest and most effective approach.

Preventing Mould and Mildew from Coming Back

While pressure washing can remove mould and mildew, it’s not a permanent fix unless preventive measures are taken. Here are a few ways to reduce the chances of future growth:

• Improve drainage around your home to avoid standing water.

• Trim back trees and bushes to increase sunlight exposure and reduce shade.

• Clean gutters regularly to prevent overflow and water pooling.

• Schedule regular cleanings—most experts recommend pressure or soft washing once a year, especially in humid or wet climates.

Should You Hire a Professional?

DIY pressure washing can work for simple jobs, but mold and mildew removal is often best left to the pros. Professionals have access to commercial-grade equipment, safe cleaning solutions, and the expertise to avoid damaging your home’s exterior. They can also determine whether pressure washing or soft washing is the better option for your particular situation.

Final Thoughts

Yes, pressure washing can effectively remove mold and mildew from many outdoor surfaces, especially when combined with the right cleaning agents. But for long-term results and to avoid damaging your property, proper technique and surface-specific treatment are essential.

Whether you’re tackling a small mold patch on your patio or dealing with widespread mildew on your siding, a well-executed pressure wash can restore your home’s beauty and protect its integrity.

Ready to banish mold and mildew from your home’s exterior? Contact our pressure washing experts today for a safe, thorough, and long-lasting clean that restores your property’s beauty and prevents future growth.