Soft Wash vs Pressure Washing: Which Do You Need?

What's the Difference Between Soft Wash and Pressure Washing?

Soft washing uses low water pressure (under 500 PSI) with cleaning chemicals to remove dirt, algae, mold, and mildew. Pressure washing uses high water pressure (1,500-4,000 PSI) to blast away grime with force alone. The difference: soft washing lets chemicals do the work, pressure washing relies on brute force.

Most homeowners use these terms interchangeably, but they're different methods for different surfaces. Pick the wrong one and you'll either damage something or waste your money on results that don't last.

When Should You Use Soft Washing?

Soft wash anything that high pressure would damage: roofs, vinyl siding, stucco, wood, and painted surfaces. It's also better for organic stuff like algae, mold, mildew, or lichen because the cleaning solution kills the growth at the root instead of just blasting the surface layer off.

Surfaces you should soft wash:

• Roofs (all types) - Shingles, tile, slate, metal. High pressure strips granules and voids warranties.
• Vinyl and aluminum siding - Pressure can force water behind panels and dent aluminum.
• Stucco and EIFS - Porous surfaces absorb water if blasted at high pressure.
• Wood siding, decks, and fences - High pressure causes splintering and raised grain.
• Painted surfaces - Pressure strips paint and damages the underlying surface.
• Outdoor furniture and screens - Too delicate for high pressure.

When Should You Use Pressure Washing?

Pressure wash hard surfaces: concrete driveways, sidewalks, patios, and brick or stone that can take the abuse. These materials are dense enough that high water pressure strips out embedded dirt without damage.

Surfaces suited for pressure washing:

• Concrete driveways and sidewalks - Handles up to 3,000+ PSI when properly done.
• Brick and stone pavers - Dense enough for moderate to high pressure.
• Garage floors - Oil stains often need the mechanical action of pressure.
• Retaining walls - Solid concrete or stone can be pressure washed.
• Pool decks - Concrete and stone surfaces around pools.

Even on concrete, pros usually pretreat with cleaning solution first. This lets you use lower pressure and get better results. The chemical kills the grime; the pressure rinses it away.

Can Pressure Washing Damage Your Home?

Yes. Pressure washing causes real damage when used wrong or on the wrong surfaces. We've seen etched concrete, splintered wood, stripped paint, damaged shingles, and water forced behind siding into wall cavities.

Here's what goes wrong, surface by surface:

• Asphalt shingles: Pressure above 500 PSI strips the protective granule coating. Once granules are gone, shingles deteriorate rapidly. Most manufacturers void warranties if you pressure wash.
• Wood: High pressure causes splintering, raises the wood grain, and can gouge soft woods like cedar and pine. The damage requires sanding to fix.
• Vinyl siding: Pressure can force water behind the panels, leading to mold growth inside walls. It can also crack older vinyl.
• Concrete: Holding the wand too close or using too high pressure creates visible lines and pitting in the surface that are permanent.
• Windows: Can shatter glass or force water past seals into the frame.

How Long Do Results Last?

Soft washing lasts 1-3 years because the cleaning solution kills growth at the root. Pressure washing lasts 6-12 months because it only scrapes off the surface layer.

Think about what's causing the stains. Black streaks on roofs, green algae on siding, mold on decks: these are living organisms. Pressure washing removes what you can see, but spores stay in the pores of the material. Those spores grow back fast because you just cleared out their competition.

Soft wash chemicals penetrate the surface and kill everything. It takes longer for new spores to move in because the old growth is actually dead, not just relocated.

How Much Does Each Method Cost?

Around Charlotte, soft washing runs $200-$600 for a house and $400-$1,000 for a roof. Pressure washing is $150-$400 for driveways and $100-$300 for patios and sidewalks.

Soft washing costs a bit more upfront because of the chemicals and specialized equipment. But you may spend less over time since results last longer and you're not paying for annual cleanings.