Two completely different methods. Knowing which to use saves your home from damage. Pressure wash uses high-PSI water 3,500+ to physically blast grime off the surface. Best for concrete driveways, brick walkways and patios, exposed aggregate, stone pool decks, composite decking at mid-PSI. Soft-wash uses low-pressure under 500 PSI with a biodegradable chemical solution. The chemistry kills algae and mildew at the root, then a gentle rinse takes it away. Best for vinyl siding because high-PSI cracks seams and damages vapor barrier. Aged brick from 1900s–1950s because mortar crumbles under high pressure. Painted wood because high-PSI strips paint. Stucco. Cedar shakes and shingles. Roofing always gets soft-wash. The most common Toronto mistake: renting a pressure washer to clean vinyl siding. We get the call afterward — water injection into the seams, sometimes inside the wall cavity. Soft-wash is the only safe method on vinyl. The most common cottage mistake: pressure washing cedar siding. The high pressure splinters cedar, opens wood grain, accelerates rot. Always soft-wash cedar. Heritage homes — the Kingsway, Cabbagetown, Forest Hill, Moore Park, original Rosedale — always soft-wash. Aged brick mortar is fragile. High-PSI blows out joint mortar that costs thousands to re-point.