What Soft Washing Means for Your Siding
Low pressure, the right solution, and time. Here is what actually happens during a house wash and why the pressure is the least important part of it.
The usual reaction to watching a house get soft washed is some version of the same thing: that does not seem like enough pressure.
It is not much pressure. That is the point.
What is actually happening
A house wash has four parts, and only one of them involves water doing work.
Apply. A cleaning solution goes onto the siding at low pressure, from the bottom up so nothing runs down over dry siding and streaks.
Dwell. It sits. This is the part that does the cleaning. The solution breaks down the algae and mildew at the root instead of knocking the visible layer off. On a badly grown wall you can watch the green disappear before anything gets rinsed.
Rinse. Top down, low pressure, until everything is off and the water running off the wall is clear.
Check. Walk it, look at the corners, the soffits, the areas behind shrubs, and anywhere the first pass did not fully take.
The pressure involved is closer to a strong garden hose than to what most people picture.
Why blasting siding is a bad idea
It drives water where water should not go. Siding sheds water running down it. It is not designed to resist water shot upward at high pressure into the lap. Once water is behind the siding it sits there, and what happens next is a much bigger repair than a wash.
It marks the material. Vinyl chalks and scars. Painted wood loses paint. Fiber cement takes visible etching. Stucco comes off in patches.
It does not solve the problem anyway. High pressure removes what you can see. The growth is still established in the surface, so it returns quickly, and now you have both the regrowth and the damage.
It tears screens and forces water into fixtures. Window screens, dryer vents, exterior outlets, and light fixtures all lose to a pressure washer.
What we do around the work
Landscaping gets wet down first and rinsed after. Pre-wetting is the real protection. A saturated plant takes up far less of anything that runs off the wall than a dry one.
Windows and openings get checked. Latched, and anything already leaking gets pointed out rather than discovered.
Fixtures and outlets get worked around. Not blasted, not ignored.
Grass and beds get a final rinse. Cheap insurance and thirty seconds of work.
What soft washing will not do
It will not restore chalky vinyl. Oxidation is pigment breakdown in the material itself. The wall will be genuinely clean and it will still look faded, and that is worth understanding before rather than after.
It will not repaint anything. Paint that is already failing will keep failing, and cleaning may lift more of what was already loose.
It will not fix siding that is warped, cracked, or improperly installed.
It will not remove artillery fungus, those tiny hard black spots near mulch beds. Almost nothing does.
How long it lasts
In this climate, a properly soft washed house looks right for about a year. Heavy shade or dense tree cover can shorten that. An open, sunny exposure can stretch it.
The reason it lasts that long instead of a couple of months is entirely the solution. That is the whole difference between soft washing and rinsing, and it is what you are actually paying for.
What to ask
If you are getting quotes, ask what pressure they run on siding and whether a cleaning solution is applied and given time to work.
You will learn everything you need to know from how quickly they answer.
Have a surface you are not sure about?
Send a photo and tell us what you are dealing with. You will get a straight answer, including if the answer is that cleaning will not fix it.
