Concrete comes back further than people expect.

What is actually growing on your driveway

The black staining on a Florida driveway is not dirt. It is algae, and it lives in the surface of the concrete rather than sitting on top of it, which is why a hose and a stiff brush do almost nothing to it. The green film on a shaded walkway and the black speckling on a north facing wall are the same story in a different place.

Then there is everything else a slab collects. Rust runs from sprinkler water that comes out of a well, dark tannin staining under an oak, oil where the car sits, and a gray film of road grit along the apron. All of it comes off, and all of it comes off differently. Pressure on its own is the wrong tool for most of it.

So a wash starts with the right cleaner on the surface, left long enough to kill the growth and loosen the staining, and then the pressure carries it away. Doing it in that order is why the concrete stays clean longer than a slab that was simply blasted with water.

• Cleaner applied and given time before any pressure
• Surface cleaner across the full width, no wand arcs
• Low pressure soft wash on stucco, siding and soffit
• Plants soaked before we start and rinsed after
• Everything flushed down to the street at the end

A surface cleaner, and why it matters

A wand puts all the water through one narrow jet. Waved across a driveway it leaves a pattern of arcs, and once you have seen them in low evening light you cannot stop seeing them. They stay for years, because the wand has cut the surface of the concrete unevenly.

A surface cleaner is a round housing with jets on a spinning bar that covers the full width at one even pressure. It walks across a slab the way a mower walks across grass, and it leaves a flat clean, so the driveway reads as one surface instead of a record of where somebody swung their arm.

Detail work still needs a wand, at the edges, up steps and along a garage threshold, and that gets done deliberately rather than as the whole job. The field of the slab is cleaned evenly and the edges are cut in, which is the same discipline as a paint job.

House washing, and the pressure that ruins stucco

A house wash is a different job to a driveway. Walls get low pressure and a cleaner, which is the only safe way to take mildew off stucco, off vinyl and off painted block. High pressure on a wall forces water in behind the finish, chews texture off stucco and can push water past a window frame.

This is also the step that decides how long an exterior paint job lasts. Chalk and mildew left on a wall become the layer the new paint is stuck to, and paint stuck to loose chalk lets go early. When a wash is the first stage of a repaint, we clean it knowing something is going on top of it.

Soffit, fascia and the face of the gutters come back at the same time. Those are the parts people forget about, and they are also the parts that leave a clean house looking half done when they get skipped.

Pool decks, pavers and what is around the water

Pool decks are usually the dirtiest surface on a property and the one people most want back. Textured deck coatings and pavers both hold algae in the low spots, so they want cleaner and even pressure rather than force. Push too hard on a paver and you take the top off it and leave it looking chewed.

Paver joints lose sand when they get cleaned. That is normal, and re-sanding is part of doing pavers properly instead of something to spring on you afterwards. Tell us what surface you have and we will tell you what it needs before you book anything.

Around a pool we plan where the water goes before we start, the same way we plan where overspray goes on a paint job. Cleaner running into the pool is somebody's afternoon gone, and it is avoidable with five minutes of thinking first.

Washing before painting, and washing on its own

When a wash is the first stage of an exterior repaint it gets priced inside the paint job rather than added on top of it. It is the same work either way, but the standard is higher, because the wall has to be clean enough to bond to and dry enough to coat.

Plenty of the washing we do has no painting after it. Sometimes the paint on a house is fine and it is the algae and the dirt making the place look tired. We would much rather tell you that and wash it than sell you a repaint you do not need for another three years.

If you want the concrete sealed after a wash, ask when you call. Sealing wants a properly clean and properly dry slab, so it never happens on the same visit, and it is a separate decision with its own number.