Home & Building Soft Washing

Soft washing uses about the same pressure as a garden hose nozzle — combined with cleaning solutions that do the actual work. The chemicals break down organic growth at the root level, killing moss and algae so they don't regrow immediately. This method is safer for siding, won't force water behind sheathing, and doesn't strip paint or damage wood grain.

Oregon's north-facing walls and shaded areas grow moss and algae year-round. Soft washing kills that growth and leaves a residual effect that keeps surfaces cleaner for 18-24 months, compared to 6-8 months after pressure washing. We use sodium hypochlorite-based solutions (similar to pool shock) mixed with surfactants. These break down into salt and water after application and won't harm plants if we pre-wet and rinse landscaping properly.

“Soft washing uses about the same pressure as a garden hose nozzle — combined with cleaning solutions that do the actual work.”

Vinyl siding, wood siding, stucco, and painted surfaces all benefit from soft washing. We adjust chemical strength based on the surface and the level of growth. Heavy moss may require a second application or some manual scraping before treatment. Composition shingle roofs get the same low-pressure approach — walking on a roof with a pressure wand breaks granules loose and voids most warranties.

AWP Exterior Cleaning handles house washing for residential and commercial properties across Oregon and Western Washington. Properties in both states deal with constant moisture from fall through spring, then UV exposure and drying in summer. North-facing walls stay damp longer and grow moss faster. Coastal properties in Western Washington see heavier buildup than valley properties in Oregon, but both climates require regular exterior maintenance.

We pre-wet all landscaping before applying chemicals, then rinse everything thoroughly afterward. Sodium hypochlorite breaks down into salt and water after application and won't harm plants when proper rinsing is done. We've never had plant damage when the process is followed correctly.

Typical house washing runs $300-$600 depending on square footage and growth severity. Results last longer than pressure washing, so many customers move to a two-year cleaning cycle after the first treatment. If you're seeing green or black streaks on your siding, the growth is already established and needs treatment.