Most homeowners assume that "pressure washing" and "soft washing" are basically the same thing — just different words for blasting water at a surface. In reality, they're fundamentally different techniques with very different applications. Using the wrong method on the wrong surface is one of the most common and costly mistakes in exterior cleaning.
This guide breaks down exactly what each method is, what it does (and doesn't do), which surfaces require which approach, and why it matters for your home in Dallas specifically.
The Short Answer
Pressure washing uses high-pressure water (1,500–4,000+ PSI) to blast away tough stains from hard, durable surfaces like concrete, brick, and pavers. Soft washing uses low pressure (under 500 PSI) combined with specialized cleaning solutions to safely clean delicate surfaces like siding, roofs, and wood. Most homes need both — pressure washing for hard surfaces below and soft washing for siding and roof above.
What Is Pressure Washing?
Pressure washing (also called power washing) uses a high-pressure pump to force water through a nozzle at pressures typically ranging from 1,500 to 4,000+ PSI (pounds per square inch). The mechanical force of the water itself is the primary cleaning agent — it physically dislodges and removes dirt, grime, oil, and buildup from surfaces.
Some pressure washers also heat the water (hot water pressure washers), which dramatically improves effectiveness on oil and grease. At White Rock Wash, we use hot water equipment for driveway and concrete cleaning — especially important in Dallas where motor oil staining in garages and driveways is extremely common.
Pressure Washing Works Best For:
Pressure Washing Is Wrong For:
Important: High-pressure water on siding can force moisture behind panels, creating conditions for mold growth inside your walls. It can also void manufacturer warranties on vinyl siding and damage window seals. This is a real risk, not an exaggeration.
What Is Soft Washing?
Soft washing uses low-pressure water (typically 40–500 PSI — similar to or lower than a garden hose) combined with professional-grade cleaning solutions to clean surfaces. The cleaning chemistry does the heavy lifting, not the water pressure. Solutions typically contain a blend of surfactants (to help solutions penetrate and lift organic matter), sodium hypochlorite (to kill mold, mildew, algae, and bacteria at the root), and neutralizers to protect plants and landscaping.
The solution is applied to the surface, allowed to dwell (usually 5–15 minutes), and then rinsed with low-pressure water. Because the chemistry kills organic growth at the cellular level rather than just blasting it off, soft-washed surfaces stay cleaner longer — mold and algae that have been killed won't regrow as quickly as surfaces that were just mechanically scrubbed.
Soft Washing Works Best For:
Soft Wash vs. Pressure Wash: Side-by-Side Comparison
| Factor | Soft Washing | Pressure Washing |
|---|---|---|
| Water Pressure | 40–500 PSI (low) | 1,500–4,000+ PSI (high) |
| Primary Cleaning Agent | Chemical solutions (surfactants, sanitizers) | Mechanical water force |
| Best For | Siding, roofs, wood, painted surfaces | Concrete, brick, driveways, hard surfaces |
| Kills Mold/Algae | Yes — at the root | Partially — removes surface growth only |
| Results Duration | Longer lasting (mold killed, not just removed) | Shorter (regrowth from surviving spores) |
| Risk of Surface Damage | Very low when done correctly | Higher — wrong PSI can pit, etch, or penetrate surfaces |
| Equipment Required | Soft wash system with chemical metering | High-pressure pump and appropriate nozzles |
| Typical Dallas Use Case | House wash, fence, wood deck | Driveway, patio, walkways, brick |
How Professional Companies Handle a Dallas Home
A professional exterior cleaning crew doesn't use just one method for everything. A typical full-property service on a Dallas home looks like this:
Soft Wash the House Exterior
The siding, eaves, fascia, and any painted wood trim are treated with a soft wash solution. The chemistry is applied at low pressure, allowed to dwell, then rinsed gently. This removes mold, mildew, algae, and grime without any risk to the siding panels, window seals, or underlying moisture barrier.
Pressure Wash the Driveway & Concrete
Concrete surfaces are pre-treated with a degreaser where needed, then hot-water pressure washed at 2,500–3,500 PSI using a surface cleaner attachment (which distributes pressure evenly and prevents streaking). Oil stains get focused treatment.
Moderate-Pressure on Patios & Walkways
Stamped concrete or pavers get attention to not damage the surface pattern or joint sand. Stone patios may get soft wash pre-treatment for algae, then moderate rinse pressure.
Soft Wash or Low Pressure on Fences & Wood
Wood fences and decks are cleaned with wood-safe solutions and low pressure to avoid splintering or grain raising. Vinyl fences can handle moderate pressure but still benefit from chemical pre-treatment for stubborn mildew.
Protect Landscaping Throughout
Before any chemical application, plants and landscaping near the work area are pre-wetted and post-rinsed. Professional-grade soft wash solutions use biodegradable surfactants and neutralizers that are safe for established plants when properly diluted.
Why Soft Washing Is Especially Important in Dallas
Dallas's combination of heat, humidity cycles, and abundant tree canopy creates conditions where mold and algae growth on siding is nearly inevitable — especially on north-facing walls and shaded areas.
Many Dallas homeowners notice green or black streaking on siding, particularly in neighborhoods with mature trees like Lakewood, White Rock Lake, and East Dallas. This is almost always algae or mold growth, and it's not just cosmetic — left untreated, it can stain siding permanently, degrade paint, and eventually penetrate porous materials.
Soft washing doesn't just clean the surface — it kills the organism at its source. High-pressure washing blasts away the visible growth but leaves behind spores and hyphae embedded in the surface, which means the algae returns faster. Soft-washed surfaces typically stay clean 2–3x longer than high-pressure washed surfaces for the same organic growth problem.
Questions to Ask Any Pressure Washing Company in Dallas
Before hiring a company, make sure they understand the difference between methods and can explain their approach.
What method will you use on my siding?
Why it matters: The answer should be "soft wash" or "low-pressure with chemical treatment" — not "high pressure" or "pressure washing." If they say they pressure wash everything the same way, that's a red flag.
What cleaning solutions do you use?
Why it matters: Professional-grade solutions are SH-based (sodium hypochlorite) with surfactants and neutralizers. Beware of companies that refuse to explain what they use or use generic household bleach at full concentration.
How will you protect my landscaping?
Why it matters: Pre-wetting plants, using appropriate dilution rates, and post-rinsing is standard practice. If they have no answer, your landscaping may be at risk.
Do you use a surface cleaner for concrete?
Why it matters: A spinning surface cleaner attachment distributes pressure evenly and prevents the streaking lines that a wand creates. It also cleans more efficiently. Good companies use this as standard equipment.
Are you insured?
Why it matters: Non-negotiable. Any company working on your property should carry general liability insurance. Ask for proof.
The Bottom Line
Both soft washing and pressure washing are valuable tools — the key is matching the right method to each surface. Professional exterior cleaning companies use both, switching techniques based on what each surface requires.
At White Rock Wash, we soft wash all siding, wood, and painted surfaces and pressure wash concrete, driveways, and hard surfaces. Every job starts with an assessment to determine the right approach — because getting it wrong isn't just ineffective, it can cause damage that costs more to fix than the cleaning cost itself.
If you're in Dallas and ready for a professional exterior cleaning, we'd be happy to walk you through exactly what approach we'd use for your specific home and surfaces. Get a free quote today.
Ready for Professional Exterior Cleaning?
We use the right method for every surface. Free estimates, fully insured, Dallas-based.