House Washing in Vancouver, WA: Soft Wash or Pressure Wash?
The green film on Clark County siding is algae, and blasting it with high pressure is how siding gets ruined. Here is when soft washing is right, when pressure washing is right, and what a proper house wash looks like.
Short answer: siding gets soft washed, concrete gets pressure washed, and mixing those up is how exteriors get damaged. The green film that grows on north-facing siding all over Vancouver and Clark County is algae, and it comes off with a low-pressure wash and the right cleaning solution. High pressure on vinyl or wood siding forces water behind the panels, strips paint, and voids some siding warranties, which is why the cheapest quote on a house wash is often the most expensive one you can accept.
Why every house here turns green
Algae and mildew need shade and moisture, and a Pacific Northwest winter delivers eight months of both. North and east walls, under eaves, and anywhere trees block sun will grow the film first. It is not just cosmetic: the growth holds moisture against the surface, which shortens paint life and feeds the conditions rot needs.
Soft washing: siding, roofs, painted wood
A soft wash uses garden-hose-level pressure with a cleaning solution that kills the growth, then rinses it away. Done right, the algae dies at the root, so the siding stays clean far longer than a pressure-only blast that just shaves the surface off the growth and leaves it to regrow. Vinyl, fiber cement, painted wood, stucco, and roofs should all be washed this way. If a quote for your siding only mentions a pressure washer, ask what pressure they intend to use on the walls. It is a fair question, and the answer tells you a lot.
Pressure washing: concrete and stone
Driveways, walkways, patios, and pavers are where real pressure belongs. The transformation on a Clark County driveway that has not been cleaned in a few years is dramatic, which is why before-and-after photos of concrete are the ones you always see. Decks sit in between: wood decking takes a careful low-to-moderate pressure wash, never the tip you use on concrete, or the grain furs up and splinters.
When to do it, and how often
Late spring through early fall is the window, once the surfaces can dry. For most homes here, a full exterior wash every one to two years keeps growth from getting established, and it is the single best preparation for exterior paint to last. We fold exterior washing into seasonal care for members for exactly that reason: it is cheap prevention against expensive problems.
One team can wash the house, clean the concrete, and flag anything underneath that needs attention while we are up close to it. See Pressure Washing & House Washing