Softwashing

Softwashing is a cleaning method that uses low-pressure water, typically with specialized cleaning solutions, to remove dirt, organic growth, mold, mildew, and algae from exterior surfaces. Unlike high-pressure power washing, softwashing relies more on chemical action and only light water pressure to minimize surface damage while lifting contaminants from the substrate.

The process centers on applying a cleaning solution that kills and loosens biological growth and soils. Common formulations include diluted sodium hypochlorite (household bleach) or other biocides, often combined with surfactants to improve wetting and dwell time. After allowing the solution to act, the surface is rinsed with low-pressure water to wash away loosened material. The approach reduces the risk of stripping or gouging delicate materials and is typically performed with pump sprayers, low-pressure spray systems, and protective equipment.

Applications include exterior siding (vinyl, wood, and composite), roofs, decks, fences, masonry, and other porous or fragile surfaces. Surfaces that are prone to algae, moss, or mildew growth are common targets. The technique is chosen when chemical cleaning is appropriate and when high-pressure cleaning could cause damage to the substrate or void warranties.

Safety and environmental considerations are integral. Operators protect landscaping, pets, and surrounding vegetation, contain runoff when possible, and follow local regulations regarding chemical use. Softwashing may require periodic repetition to maintain results, and not all surfaces or stains are suitable for this method. It is often contrasted with pressure washing, which relies more on physical force than chemical action.