Washed at the right pressure for the surface

What washing a house actually involves

The order matters more than the machine does. We walk the property first and look at what we are dealing with: the surface material, what is growing on it, where the water is going to run, what is planted underneath. Then the beds and any sensitive plantings get wet down before anything else happens, because a soaked plant sheds a splash and a dry one drinks it. Gutters and downspouts get checked so the runoff has somewhere to go instead of pooling against a foundation.

Then the surface gets treated and given time to work. That is the part people skip, and it is the part that does the job. A green film on north-facing vinyl is algae, and algae dies chemically, not by being blasted off. Blasting it takes the top layer of the surface with it and leaves the roots behind, so it comes back darker within a season. Let the solution sit, then rinse it down with volume rather than force, working top to bottom so nothing dries in streaks.

When it is done right you cannot tell where we started and where we stopped. No wand marks on the concrete, no zebra striping down the driveway, no clean square in the middle of a dirty slab. Siding is one even color from the soffit to the foundation. Concrete looks like concrete again instead of looking scoured. On a walk you should see mortar joints and the aggregate in the mix, not swirl patterns from somebody rushing a fan tip across it.

• Beds and plantings soaked before we start
• Surface treated, given time, then rinsed
• Concrete cleaned even, no wand stripes
• Siding washed top down, soffit to foundation
• Runoff directed away from the foundation

Vinyl, brick and Hardie around here

Most of the newer subdivisions between Smyrna and La Vergne went up in vinyl siding, or vinyl with a brick or stone water table across the front. Vinyl is the easy one to clean and the easy one to ruin. It laps, so every course has an open bottom edge, and water driven up under that lap from below sits in the wall cavity where nothing dries it. Wash it downward, at low pressure, and it comes clean. Wash it upward with a tight tip and you have put water behind the wall.

Fiber cement is on a lot of the newer builds and it behaves differently. It holds paint well, which means the finish is what you are cleaning, not the board. Too much pressure chalks the coating and takes the sheen off in patches you will notice the first sunny afternoon. Older lots around here bring full brick and painted wood trim, and brick has its own problem: the mortar joints are softer than the brick face, and a tight tip will cut a joint out and leave you with an opening water can follow.

The other thing to know about this housing stock is where the growth lives. North walls, anything under a big oak, anywhere a gutter has been overflowing down the same corner for a while. Those spots need the solution and the dwell time, not more pressure. A wall that comes clean everywhere except one shaded corner usually means somebody rinsed instead of treating, and that corner will be the first thing you see from the street by the time the weather warms up.

Middle Tennessee weather and green concrete

Humid summers, wet springs, and shade hold moisture on a surface long enough for growth to take. That is why a driveway here goes green and black along the edges while the center stays lighter. The center dries. The edges stay damp under grass clippings and leaf litter, and that organic layer feeds what grows on top of the concrete. Same reason the north side of a house always looks worse than the south side even though both got built the same week.

Concrete around Smyrna is mostly poured slabs and broom-finished walks, and the broom finish is a texture full of tiny ridges. Dirt settles into those ridges and a fan tip only skims the tops, which is how you get a driveway that looks clean when it is wet and looks blotchy the second it dries. A surface cleaner rides flat and covers the full width at once, so the texture cleans evenly instead of in stripes. That is a different tool from a wand, and the difference shows up on the dry slab.

New subdivision driveways bring their own problem. Fresh concrete is porous and stays that way for a good while, so tire marks, drips and rust from a sprinkler pull into the slab instead of sitting on it. Those need to be treated directly rather than hit harder. Rust in particular does not come off with pressure at all, and running the machine at it just polishes a lighter halo around the stain, which makes it more obvious than it was.

Patios, walks and what fails after

Patios and back walks collect what the driveway does not. Grill grease, pollen packed into a brick paver joint, a black ring where a planter has sat through two summers, and the slick film on shaded steps that people find out about the first wet morning. Pavers and flagstone need attention to the joints, because a tight tip aimed straight down blows the sand out and leaves stones that rock underfoot. Approach it at an angle, keep the tip moving, and put back what comes out.

Wood decks and painted porch boards are the surface people damage most often. Wood is soft, and the grain lifts and furs the moment you push too hard, so you get a deck that looks bright the day it was cleaned and rough enough to catch a sock by fall. Board goes with the grain, gentle, and any stain gets stripped chemically rather than pushed off. A pressure-scarred board holds water in the raised grain, and that is where rot starts.

What fails after a wash is almost always drainage or downspouts nobody looked at. If a gutter dumps at a corner every storm, that corner grows back first no matter how clean it got. Same with a walk that sits low and holds a puddle for a day and a half after rain. We will tell you when we see it, because otherwise you are paying to clean the same stripe every year and wondering why yours does not hold like your neighbor's does.