There are two primary techniques for washing a house: pressure washing and soft washing. While both utilize water to clean, they differ significantly in their approach and the type of surfaces they are best suited for.

Pressure Washing involves using a high-pressure stream of water to remove dirt, grime, mold, mildew, and other contaminants from exterior surfaces. This method is highly effective for durable materials like concrete, brick, and some types of siding that can withstand the force of the water. The high pressure can quickly blast away stubborn stains and build-up. However, it's crucial to use caution and the correct pressure setting, as excessive force can damage more delicate surfaces, strip paint, or force water into cracks and crevices, leading to moisture problems.

Soft Washing, in contrast, employs a low-pressure wash combined with specialized cleaning solutions (typically detergents, bleach, or other chemical agents) to clean surfaces. Instead of relying on brute force, soft washing allows the cleaning solutions to break down and lift away contaminants like mold, algae, mildew, and dirt. After the solution has had time to work, it is gently rinsed away with a low-pressure stream of water, similar to the pressure of a garden hose. This technique is ideal for more delicate materials such as stucco, vinyl siding, painted wood, and roofs, where high pressure could cause damage. Soft washing is also often preferred for its ability to kill organic growth at the root, leading to a longer-lasting clean.

Cleaning wooden decks and fences requires a delicate touch, as wood is a natural material that can be easily damaged by improper cleaning techniques. The goal is not just to remove dirt and organic growth but also to preserve the integrity, natural pH, and color of the wood.

Soft Washing for Decks and Fences (Preferred Method)

For wooden decks and fences, soft washing is generally the preferred and safer method. This approach prioritizes the health of the wood while effectively cleaning it.

• Gentle Cleaning Action: Soft washing uses low pressure, typically similar to a garden hose, to apply specialized cleaning solutions. This prevents the high-pressure damage that can occur with pressure washing, such as splintering, "furring" (raising of the wood grain), or even etching into the wood fibers.

• Targeted Chemical Solutions: This is where soft washing truly shines for wood. Instead of relying solely on mechanical force, it uses carefully formulated chemical solutions to:

• Remove Organic Growth: Solutions containing oxygen bleach (sodium percarbonate) or other wood-specific cleaners are highly effective at breaking down and killing mold, mildew, algae, and moss. These organic growths are what often cause the unsightly black or green discoloration on wood.

• Lift Dirt and Grime: Surfactants in the cleaning solutions help to emulsify and lift embedded dirt, pollen, and other pollutants from the wood's surface.

• Restore Natural Color and pH: Many professional-grade wood cleaners are designed to restore the wood's natural appearance. The initial cleaning solution often raises the wood's pH, which can leave it looking dull or slightly discolored. To counteract this and brighten the wood, a wood brightener (often containing oxalic acid or citric acid) is applied as a second step. This brightener neutralizes the high pH, bringing the wood back to its natural, vibrant color and preparing it for staining or sealing. This two-step "clean and brighten" process is crucial for optimal results and longevity of wood.

• Longer-Lasting Clean: By killing organic growth at its source rather than just blasting it off, soft washing can provide a longer-lasting clean and inhibit future regrowth.

• Safety for Surroundings: Soft washing solutions, when properly diluted and applied, are often biodegradable and less likely to harm surrounding landscaping, plants, or pets compared to harsh, undirected pressure washing.

Pressure Washing for Decks and Fences (Use with Extreme Caution)

While pressure washing can be used on decks and fences, it comes with significant risks to the wood and is generally not recommended as the primary cleaning method without specialized knowledge and equipment.

• Risk of Damage: High pressure can easily damage wood, leading to:

• Furring: The wood fibers can be lifted and splintered, creating a fuzzy texture.

• Etching/Gouging: Concentrated pressure can carve lines or grooves into the wood, causing irreversible damage.

• Water Penetration: High pressure can force water deep into the wood, leading to prolonged drying times, swelling, and potential for rot or mold growth from within.

• Stripping Finishes: While sometimes desired for removing old stains, uncontrolled pressure washing can unevenly strip finishes, creating a patchy appearance.

• Less Effective on Organic Growth: Pressure washing blasts off the surface layer of mold and mildew but may not kill the spores embedded deeper in the wood, leading to quicker regrowth.

• Uneven Cleaning: Without proper technique, it's easy to create "tiger stripes" or clean some areas more aggressively than others.

When it comes to cleaning driveways, both pressure washing and soft washing have their applications, though pressure washing is generally the more common and often preferred method for the robust surfaces typically found in driveways.

Pressure Washing for Driveways

Pressure washing is highly effective for driveways due to the typical materials they're made from, such as concrete, asphalt, pavers, and brick. These surfaces are generally durable enough to withstand high-pressure water, which excels at removing:

• Heavy dirt and grime: Accumulated dirt, mud, and general atmospheric pollutants are quickly dislodged by the force of the water.

• Oil and grease stains: While stubborn oil stains may require pre-treatment with a degreaser, the high pressure helps to lift and rinse them away.

• Mold, mildew, and algae: These organic growths, common in damp or shaded areas, are effectively blasted off, restoring the driveway's appearance and improving traction.

• Moss and lichen: These growths can penetrate porous surfaces; pressure washing effectively removes them, though some deeper growth may require additional treatment.

Techniques for pressure washing driveways often involve:

• Pre-treatment: Applying a degreaser or specialized concrete cleaner to stubborn stains like oil or rust before washing can significantly improve results.

• Surface cleaners: For large driveways, a surface cleaner attachment is highly recommended. These tools attach to the pressure washer and use rotating nozzles within a shroud to clean a wider, more even path, preventing "tiger stripes" or uneven cleaning marks.

Soft Washing for Driveways

While less common as the sole method for concrete or asphalt driveways, soft washing can be beneficial in specific scenarios or as a preliminary step:

• Delicate driveway materials: Some driveways might incorporate more delicate materials like certain types of natural stone or decorative pavers that could be damaged by high pressure. In such cases, soft washing provides a safer cleaning approach.

• Heavy organic growth: For driveways heavily covered in mold, algae, or moss, a soft wash solution containing appropriate chemicals (like diluted sodium hypochlorite or specialized algaecides) can effectively kill the growth at the root level. This can provide a longer-lasting clean compared to simply blasting it away with pressure.

• Pre-treatment for pressure washing: Soft washing can be used as a pre-treatment step for a pressure wash. Applying a soft wash solution to a heavily soiled driveway can break down the grime, making the subsequent pressure washing more efficient and requiring less aggressive pressure.

• Preventative maintenance: For driveways that are already relatively clean but are prone to recurring organic growth, periodic soft washing can help inhibit regrowth and maintain a cleaner appearance with less effort.