House washing is a low-pressure soft wash of the outside of your home: the siding, the soffits and fascia, the gutter fronts and the trim, cleaned with a cleaner that kills algae and rinsed off gently. On a Michigan house it is worth doing once a year, and the shaded north and east walls set the schedule. Vinyl, painted aluminum and brick each need a slightly different hand, and the sections below cover how each one is cleaned.
What a house wash covers
A house wash is the soft wash half of our pressure washing and soft washing service. On every house it covers:
All the siding, whatever it is made of, washed at low pressure with a cleaner and rinsed
Soffits, fascia and the outside face of the gutters
Exterior light fixtures, rinsed and cleared of webs
Wasp and mud dauber nests, cleared off the eaves and fixtures
Beds and shrubs, soaked with plain water before the cleaner goes on and rinsed again at the end
A walk around the house with you before we pack up
Driveways, walks, patios and decks are separate items with their own price, because they get a different method. Windows are separate too. Rinse water from a house wash dries on the glass, so if you want clear windows, book a window cleaning for after the wash. If the gutters are due as well, the order is the house, then the gutters, then the glass, so nothing gets dirty twice.
Why the north side goes green first
The growth on siding needs moisture and shade. Purdue Extension says mildew shows up on walls behind trees and shrubs, where air movement is restricted, and points to dew forming on cooler parts of a house such as the eaves as a steady source of water. Here, the north and east walls get the least sun and are the last to dry after rain and dew. Those are the walls that go green or grey first, and the sunny walls stay clean.
Trees make it worse. Livonia filled in between about 1950 and 1970, and the street trees planted with those subdivisions now shade whole walls all day. In Canton, the subdivision houses carry big unbroken vinyl gables, and a shaded one holds damp across its whole face. Either way, the green is a living film rooted into the surface. A plain rinse takes the top off and the roots grow it back. The cleaner in a house wash kills it.
Because the shade falls unevenly, the walls get dirty at different rates. Some homeowners wash the shaded walls every year and the sunny ones less frequently. Tell us which sides bother you when you ask for a quote.
Vinyl siding
Vinyl moves with the weather. The vinyl siding installation manual from the Vinyl Siding Institute says a panel can expand and contract half an inch or more over 12 feet 6 inches, which is why it hangs on loose nails with unsealed laps. High-pressure water aimed at those laps from below goes straight in behind the panels.
CertainTeed, a siding maker, tells owners it does not recommend power washing its vinyl, and it recommends cleaning siding once a year so the dirt never builds up. The VSI manual adds a tip for anyone washing a whole house: start at the bottom and work up, so the wall doesn't streak.
A soft wash fits that advice. The cleaner goes on at low pressure, sits long enough to kill the growth, and comes off with a gentle rinse. On second-story gables we reach the wall without resting a ladder on the panels, because a ladder leaning on vinyl can crack it. Our post on pressure washing vs soft washing explains the reasons, surface by surface.
Painted aluminum and chalking
Painted aluminum is common on older houses here: the trim, soffits and fascia on Plymouth Township's postwar and 1970s houses, the same parts on Livonia's brick ranches, and whole walls on some homes in Farmington Hills.
Factory paint on aluminum chalks as it ages. Sherwin-Williams describes chalking as a fine white powder that forms on exterior paint as it weathers, and notes that factory-finished siding can build up a thick layer of it. Run a finger along the wall. If it comes away white, the paint is chalking. Purdue Extension explains that the powder is pigment let go as the paint film breaks down, and that it washes down onto whatever sits below, which is why brick under aluminum trim can carry pale streaks.
Chalk is where a careless wash does lasting harm. Scrubbing hard or hitting it with high pressure takes the chalk off unevenly, and the wall dries patchy and streaked in low sun. So before the whole wall gets washed, we try a small patch low down and show you how the finish comes up. The cleaner loosens the chalk and the dirt together, and an even, low-pressure rinse carries both away. A wash can't put back paint that has weathered off, so on a very chalky wall the test spot also tells you whether you are looking at a wash or a paint job.
Brick and mortar
A soft wash suits brick, and the difference is plainest on a shaded wall with dark, grown-over mortar joints.
The mortar is the part to protect. The National Park Service's Preservation Brief 1 advises beginning at 100 psi or below, as low as a garden hose, and working up only as needed, to 300 to 400 psi at the top end. The brief notes that lime mortar wears away under abrasive or mechanical cleaning, and that joints can be up to a fifth of the face of a brick wall, so worn joints add up fast and let more water into the wall.
Closer to home, the City of Northville's historic district standards tell owners to use only the gentlest cleaning method possible on brick, such as a low-pressure water spray and soft natural-bristle brushes. That fits the older houses in downtown Northville and in Plymouth by Kellogg Park, which were laid with soft lime mortar. Painted brick gets the same care as any painted wall: low pressure, so the paint stays put.
How often to wash a house in Michigan
Once a year suits a Michigan house, and CertainTeed's care advice says the same for its siding. A proper soft wash kills the growth, so the walls hold up through the season, and the shaded faces are the first to need it again. Tree cover close to the house and sprinklers that hit the siding both shorten the gap.
When you wash matters as much as how often. We wash from April to November, since the cleaner wants warm weather and a cold morning turns rinse water to ice on the walk. A late April or May wash clears off the winter's salt and grime. A wash in late September or October takes off the summer's growth while the leaves are still on the trees. The spring dates book up first, so ask early.
Questions people ask
What does a house wash include?
A house wash covers all the siding, the soffits and fascia, and the outside of the gutters, washed at low pressure with a cleaner and rinsed. Light fixtures are rinsed, wasp nests come down from the eaves, and beds are soaked before and rinsed after. Concrete, decks and windows are separate, each with its own price.
Can you wash painted aluminum siding without streaking it?
Yes, with care. Aged aluminum paint chalks, and hard scrubbing or high pressure strips the chalk unevenly and leaves the wall patchy. We try a small patch low on the wall first and show you the result, then wash with a cleaner and an even, low-pressure rinse. Heavily worn paint may need repainting after.
Is brick washed differently from vinyl?
Yes. Vinyl gets a soft wash because water forced up under the laps gets into the wall. Brick can take a little more pressure, but its mortar can't, and older lime mortar washes out of the joints under a strong jet. So brick gets a cleaner and a gentle rinse that cleans the mortar without wearing it down.
Do I need the whole house washed, or only the green side?
That depends on how the walls look. Shaded north and east walls regrow sooner than the sunny ones, so some homeowners wash those every year and the sunny sides less frequently. Others prefer one even wash so every side matches. Tell us which walls bother you, and we'll quote it either way.
Get a quote
Glass Guru has been owner-operated in Northville since 2014, and house washing runs from April to November across all ten of the towns we serve. Send the address, the siding type if you know it, and which walls you want washed, and we'll send back a quote. Get a Free Quote
