People use the two terms as if they mean the same thing. They do not, and the difference matters most on exactly the surfaces homeowners care about — siding and roofs.
The short version
- Pressure washing uses water force to remove what is sitting on a surface. Right for hard, flat, durable things: concrete, brick paving, a driveway slab.
- Soft washing uses low pressure and a cleaning solution to kill and release what is growing on a surface. Right for anything that force would damage: vinyl, painted wood, stucco, fibre cement, asphalt shingle.
Pressure removes. Soft washing treats. If the problem is algae or mildew — and in the Triangle it usually is — force alone just knocks the top layer off and it grows back within months, because the root structure is still there.
What goes wrong with pressure on the wrong surface
Vinyl siding
Vinyl is lapped, not sealed. Water driven upward at pressure goes behind the panels and sits in the wall cavity. You cannot see it from outside and it does not dry quickly. This is the most common piece of avoidable damage we get called out to look at.
Asphalt shingle
The granules on a shingle are the shingle. Blast them off and you have removed the UV layer and shortened the roof life by years. A roof that has been pressure washed often looks great for a season and then ages visibly faster than its neighbours.
Painted wood and older brick
Common through the older streets of Raleigh and Durham. Pressure lifts paint and, on soft old mortar, will cut into the joint itself. Repointing costs considerably more than washing.
What each surface actually needs
| Surface | Method | Why |
|---|---|---|
| Vinyl siding | Soft wash | Lapped panels — pressure drives water behind them |
| Brick | Soft wash | Protects mortar joints, especially on older builds |
| Stucco & fibre cement | Soft wash | Porous and easily marked |
| Painted wood | Soft wash | Pressure lifts paint |
| Asphalt shingle roof | Soft wash | Pressure strips protective granules |
| Concrete driveway | Pressure | Hard, flat, takes force well |
| Paved patio & walkway | Pressure | Same, with care around jointing sand |
Why the Triangle grows so much of this
Warm, humid, heavily shaded. It is close to ideal for algae and mildew, which is why north-facing elevations here green up so much faster than the sunny side of the same house. That green-black film on the shaded wall is biological. It needs to be killed, not blasted, or it returns before the next season.
Newer developments around Cary, Apex and Morrisville are mostly vinyl and fibre cement on open lots, where the job is pollen plus the one shaded elevation. Older Raleigh and Durham streets under canopy are established growth on painted wood or brick. Different problems, same answer: soft wash.
What we run
Both, matched to the surface, with hot and cold water on the truck. We walk the property first and tell you which elevations need what. If someone quotes you a house wash without asking what your siding is made of, that is worth noticing.