These are two different trades that share a truck. Treating them as one service is how most of the damage we get called to fix starts.
Pressure washing
High pressure, hot water, minimal chemistry. Built for hard surfaces: concrete, brick pavers, stone, metal. The job is mechanical — force lifts the grime. Use this on siding and you drive water behind it.
Soft washing
Low pressure (garden-hose level), heavy chemistry. Built for softer surfaces: stucco, Hardie, painted wood, vinyl, shingles. The job is chemical — the detergent kills the organism. Use this on concrete and it looks rinsed, not clean.
The simple rule
"If it's hard and flat, pressure-wash it. If it's the house, soft-wash it."
Roofs are soft-wash, always. The Asphalt Roofing Manufacturers Association (ARMA) explicitly warns against pressure-washing shingles — it voids most warranties and strips the granules.
