When people call for a quote, they almost always ask for “power washing.” That’s fine. I know what they mean. But when I get out to the house, a big part of my job is deciding which parts of your property should get high pressure and which parts should never see it. Getting that wrong is how siding gets damaged and how mildew is back in a few months.
Here’s how I explain the difference to my customers, and how I decide what your house actually needs.
What’s the difference between soft washing and pressure washing?
Pressure washing uses high-pressure water to physically strip dirt off a surface. It’s the right tool for hard surfaces like concrete driveways, sidewalks and patios, where you need the force to lift ground-in dirt.
Soft washing uses low pressure, roughly what comes out of a garden hose, plus a cleaning solution that kills mildew, algae and mold. The solution does the work instead of the pressure. It’s what I use on siding, roofs and anything else that can be damaged by force.
Most homes get both. On a typical job we soft wash the house and pressure wash the driveway and walkways, so each surface gets cleaned the way it should be.
Why does mildew come back so fast after I pressure wash?
This is the question that usually makes the difference click for people. High pressure can blast the green off your siding, but it doesn’t kill what’s growing there. The roots and spores are left behind, so the growth comes right back, sometimes within a season.
A soft wash kills the growth, so it takes much longer to return. One of our customers said she’d pressure washed her own house for years, and after her first soft wash she couldn’t believe how much more dirt came off. I hear that a lot.
Can you pressure wash vinyl siding?
You can, but you have to know what you’re doing, and most of the damage I see comes from people who didn’t. Vinyl siding overlaps like shingles. Aim high pressure up at it and you can drive water behind the panels, where it sits against your sheathing. Get too close and you can crack older, sun-brittle vinyl or knock panels loose.
Some siding manufacturers also warn against power washing in their warranty terms. That’s one more reason I soft wash vinyl siding instead of blasting it.
Is soft washing just bleach?
The active ingredient in most soft wash solutions is sodium hypochlorite, the same thing that’s in household bleach. We mix it down to the right strength for the surface, and add a soap so it clings to the siding and does its job instead of running straight off.
I’d rather tell you that plainly than call it some secret formula. What matters is using the right strength for the surface, protecting your plants, and rinsing properly. If you want the details on that, read how we protect plants, pets and pools during a soft wash.
How I decide what each surface gets
When I walk your property, I’m looking at a few things:
- What it’s made of. Vinyl, brick, stucco, painted wood, composite decking and asphalt shingles all need different handling. Concrete can take pressure. Your roof can’t.
- What’s on it. Green and black growth gets soft washed. Ground-in dirt, gum and grime on concrete need pressure. Rust and oil stains need their own treatment, which I cover in my post on oil and rust stains on driveways.
- What’s around it. Plants, pools, ponds, outdoor furniture and anything else I need to protect or move.
- Its condition. Old, brittle siding or loose trim gets a gentler approach, and I’ll tell you if I see something that worries me before we touch it.
I go over all of this with you before we start, so you know what we’re doing to each part of your home and why. Nobody should have to guess what a contractor is about to do to their house.
Common questions
Is power washing different from pressure washing?
Some companies use “power washing” to mean pressure washing with hot water, but there’s no official definition. Most people use the two terms the same way, and so do we.
Does soft washing work on brick and stucco?
Yes. Brick and stucco are porous and can be damaged by high pressure, so soft washing is usually the better choice for them too.
How often should I have my house soft washed?
For most homes around here, about once a year works well. Houses in heavy shade or close to trees may need it more often. I’ll give you my honest opinion when I see your house.
Not sure what your house needs?
That’s my job to figure out, not yours. If you’re in Anne Arundel, Howard or Baltimore County, call us at (410) 948-0228 or request a quote online. You can also read more about our house washing service, or see what we do in Columbia, Owings Mills and Pasadena.
Frank
Owner, Professional Power Washing