House washing: what to know

What the job involves, what changes the price, and what to ask a pro.

What house washing is

House washing cleans a home's siding, trim, windows and soffits with a low-pressure soft wash and cleaners that remove dirt, algae and mildew. It rinses the surfaces and protects plants and entry points along the way. People call when a house has dark streaks, green growth or mildew, or before selling or painting.

Signs you need it

  • Dark streaks or green algae running down siding from the roofline, especially on the north or shaded side
  • Mildew spots on siding, trim, soffits or window frames that look like black or gray patches
  • Dirt and pollen buildup on vinyl or fiber cement that dulls the finish over time
  • Spider webs, wasp nests and dust collecting under the eaves and around entry doors
  • A house being prepared for painting, a sale or a rental, where a clean exterior is wanted

What the pro does

  • Inspect the siding, trim, windows and soffits for loose panels, cracks and failed caulk that could let in water
  • Protect plants, shrubs, outdoor outlets, light fixtures and doorways, and wet down the landscape before the cleaner goes on
  • Apply the soft-wash cleaner from the bottom of the wall up, letting it dwell so it can break down algae and mildew
  • Rinse from the top down at low pressure so the cleaner does not dry on the surface or streak it
  • Check the wash for streaks and missed areas, rinse the plants again, and note any stains or damage found

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Size of the house, number of stories, and total wall area
  • Siding material, since vinyl, fiber cement, wood and stucco each need a different cleaner and rinse approach
  • Level of algae, mildew or dirt, and how long it has been building up
  • Number of windows, trim pieces and soffits that need cleaning
  • Access to the upper stories, including ladders or lifts on tall homes
  • Plant protection and landscape work needed around the house
  • Whether a protective coat or algae inhibitor is applied after the wash

What a written quote should spell out

  • Each surface included, such as siding, trim, windows and soffits, listed by name
  • Cleaner type, dwell approach and rinse method for each material
  • Plant and landscape protection steps, including wet-down and rinse
  • Whether window cleaning is included, and how frames and screens are handled
  • Whether an algae inhibitor or protective coat is included, and what it covers
  • Notes on any loose siding, failed caulk or stains found during the wash

Questions to ask before you hire

  • What cleaner do you use on my siding material, and how do you rinse it?
  • How do you protect my plants, shrubs and outdoor electrical fixtures?
  • Do you clean the windows and screens, or only the exterior walls?
  • Will the wash remove the mildew, and how soon could it come back?
  • What do you do with the cleaner runoff near my lawn and beds?
  • Can you show me a finished house of a similar material and story count?
  • Does your insurance cover work at the height of my upper stories?

Red flags

  • High-pressure washing on vinyl, painted wood or stucco that forces water behind the siding
  • No protection for plants, landscaping or light fixtures before the cleaner goes on
  • A promise that the house will look new, with no mention of the cleaner, dwell time or rinse
  • Cleaner applied to a dry or hot surface, which dries on the siding and streaks
  • Strong chemicals promised with no test spot and no plan to rinse the plants

What you can do yourself

You can safely hose down the lower walls and windows you can reach from the ground, and rinse plants before and after. Do not use a pressure washer on siding, since high pressure can drive water behind it, and do not climb a ladder to reach the upper stories or the soffits. Call a pro for a full house wash, upper stories, and mildew that does not rinse off.

Licenses and permits

House washing is often offered by general exterior cleaning companies, and rules vary by place. Check your state and local licensing requirements, and check the rules for chemical use and runoff where you work.

House washing questions

Is house washing the same as pressure washing?

No. House washing uses low pressure and a cleaner to kill and remove algae and mildew. Pressure washing uses higher pressure, which suits hard surfaces. High pressure can damage siding, so house washing is usually the right method for it.

Will the cleaner harm my plants?

It can, if plants are not protected and rinsed. Ask the pro how they cover and wet down the landscape before the wash and how they rinse it afterward.

How long does a house wash last?

It depends on the sun exposure, the tree cover and the material. A protective coat or algae inhibitor can slow the return of growth. Ask the pro what to expect on your side of the house.

Can house washing remove paint or stain?

A soft wash removes dirt and growth, not paint or stain. If the surface is peeling or failing, the pro should note it before the wash.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

Edit history

How it works

  1. 1. Describe the job

    Pick the service, add your ZIP and a sentence about what is going on.

  2. 2. Pick the pros you want

    See pros who serve your ZIP and choose who you want to hear from.

  3. 3. They reach out

    They contact you the way you chose: phone, email or in-app messages.

More roofs and exterior guides

Find a pro near you

Find a pro

About this guide

Request house washing