Soft washing uses low pressure and cleaning chemistry to clean surfaces that high-pressure washing would damage. In Boston, where siding, roofing, and painted surfaces are often decades old, soft washing is frequently the appropriate choice.
Soft washing applies cleaning solutions at 100–500 PSI — significantly below the 1,500–4,000 PSI used in standard pressure washing. The cleaning work is done by the chemistry: sodium hypochlorite or sodium percarbonate solutions that kill biological growth (algae, mildew, mold) at the cellular level. Low-pressure rinsing then removes the dead organisms and cleaning solution residue. The cleaning effect with soft wash is often more complete and longer-lasting than pressure washing because it addresses biological growth at the root rather than just removing the visible surface manifestation. PWNA soft wash certification →
Asphalt shingle roofing: always — pressure damages granules and voids warranties. Wood siding: always — high pressure raises grain and damages paint. Vinyl siding: soft wash preferred — pressure can force water behind panels. Painted surfaces: soft wash preferred — high pressure strips paint. Stucco: required — high pressure damages stucco surface and can force water into the wall assembly. Older brick: soft wash preferred — mortar joints in older Boston brick are often softer than face brick and can be eroded by high pressure. EPA safer choice cleaning products →
Sodium hypochlorite (pool-grade bleach) is the most effective soft wash chemical. It's biodegradable in diluted form and breaks down quickly, but concentrated runoff can harm plants and enter storm drains that lead to Boston Harbor. We use appropriate dilutions (0.5–3% for most siding applications, higher for roofing), pre-wet landscaping before application, and rinse thoroughly. We contain and neutralize runoff on all soft washing projects near sensitive areas in compliance with Massachusetts stormwater regulations. EPA stormwater regulations →
Properly executed soft washing kills biological growth at the root — results last longer than pressure washing, which removes surface organisms but leaves the substrate conditions that allow rapid regrowth. In Boston's humid, shaded conditions, a soft-washed house typically stays clean for 2–4 years before significant regrowth; a pressure-washed house may show regrowth within 6–12 months. This difference in longevity is the core value of soft washing for Boston homeowners who want the least frequent maintenance intervention on their home exterior. This Old House soft wash guide →
Need Soft Washing in Boston?
AURA Painting Inc serves all Boston neighborhoods. Licensed MA #193121, fully insured, 2-year warranty. Free estimates — most jobs scheduled within the week.
Call (617) 777-7700 ← Back to Soft Washing