Illustration for Judge a House Wash by Results, Not the Clock

If it’s streaky, spotty or missed whole walls, the price is too high no matter how long they took. A homeowner asked a home-improvement forum exactly this. A crew finished in about 30 minutes and charged over $500. The replies kept coming back to one question: is the house clean?

Why the clock tells you so little

Soft washing is chemistry, then a rinse. The waiting part is short. One house wash label says to let it work for 10 minutes. An EPA-accepted bleach label gives 30 minutes on siding for mildew control. A Colorado Front Range washer lists a 5 to 15 minute dwell time.

The rest is crew size, gear and prep. On a pressure washing trade forum, one owner described a two-person crew with two machines. They washed a 2,500 sq ft two-story house and its driveway in 1 hour 10 minutes, roll-up to roll-out. Another reported 45 minutes for a 2,000 sq ft house. A third said a second washer only makes things about 1.5 times faster.

Washers’ own published estimates run longer, and at least one counts prep:

  • One Charlotte company says a small single-story home takes about an hour.
  • A Midwest washer says an average house takes two to four hours.
  • The Front Range washer says most homes take 3 to 4 hours, including prep.

So a big crew can be fast and thorough. A one-person crew that finished a large two-story house in 30 minutes deserves a closer look at the walls.

Was the price normal?

Probably, for a mid-size home. One washer’s price list puts a 2,000 to 2,500 sq ft two-story home at $505. A Midwest washer quotes $450 to $750 for a standard two-story home. Our house washing cost guide has the full ranges. The price lists we checked charge by house size, not by the hour.

What a finished wash should look like

With a bleach-based soft wash, most mildew and algae staining should be gone or much lighter by the final rinse. The house wash label above says a second coat may be needed if staining persists. That’s a normal fix, not a failure.

Two things legitimately take longer:

  • No-rinse treatments. One maker says results are gradual. Green algae fades in weeks, and darker mold and moss stains over months. Ask which kind you paid for.
  • Roof moss. One washer says treated roof moss dies over one to three months. See roof soft wash results.

The walk-around checklist

Walk the house before the crew leaves, then again once it’s dry.

Check What a good job looks like If not
Shaded walls (often north-facing) No green or black left Ask for a second coat (Mold Armor label; Sonlight)
Siding color Even, no zigzag or wand lines May be chalky siding, not dirt (CertainTeed; community thread)
Soffits, peaks, gutter faces Cleaned if quoted Check your quote (KC Splash)
Plants Same color as before; rinsed Photograph them (Sonlight; Mold Armor label)
Driveway, walks, furniture No overspray or debris Ask for cleanup (Gleaming Gutters)
Oil, rust, clay stains Often not included Ask before assuming (Gleaming Gutters)

Zigzag or blotchy siding is the hard call. In a 2025 community thread, a homeowner paid $600 to wash a 2,400 sq ft home. Afterward they found uneven patches. Some pros blamed sloppy technique. Others said the siding was chalky and needed a separate oxidation treatment. One siding maker calls chalk a dull film common on pigmented materials in the sun. Our guide to chalky vinyl siding after a wash explains the difference.

Thin dirty streaks under windows can be water leaking from behind the siding. One pro in that thread suggested a gentle hose rinse instead of wiping. Wiping can disturb chalky siding. The same siding maker warns that power washing vinyl can cause moisture intrusion.

Photograph it, then ask for a touch-up

Take wide shots of each side, then close-ups of anything wrong. Some washers take their own before-and-after photos, so ask for a copy. Didn’t take “before” photos? Our guide to wash damage vs. what was already there helps you sort it out.

Then call soon, while the job is fresh. Be specific: “The north wall still has black streaks by the back door.” One Charlotte company promises to return and fix any issue at no additional cost. Ask whether yours has a similar policy.

The FTC advises never making the final payment until the work is done and you’re satisfied. Next time, settle it up front with our questions to ask a house washing company. How we check our numbers is on our methodology page.

Sources

Based on 12 sources · How we price