How to Soft Wash a House

What soft washing is (and how it differs from pressure washing)

Soft washing cleans exterior surfaces with low water pressure and a cleaning solution, rather than relying on force. The solution does the work of loosening or killing algae, mildew, mold, and grime, and a rinse carries it away. Pressure washing does the opposite: it relies on high-pressure water to blast dirt off.

Soft washing is generally preferred for surfaces that can be damaged by strong spray, such as vinyl siding, painted wood, stucco, and roofs. Many professionals use a sodium hypochlorite (bleach) based mix plus a surfactant, which is a soap-like additive that helps the solution cling to the wall. Other cleaners exist, and you can choose a gentler one if you are comfortable with slower results.

Is soft washing right for your house?

Soft washing is usually a good fit when your siding has green, black, or gray streaks, a dusty film, or a general dull look caused by organic growth. It is less suited to heavy paint peeling, rust, or deep stains that need different treatment.

Before you start, consider:

Height. Cleaning above the first storey usually means ladders or lifts. If that is needed, hiring a professional is the safer choice.
Material. Check your siding type and any manufacturer cleaning guidance or warranty. Wood, older paint, and some metals can react poorly to strong solutions.
Surroundings. Plants, pets, pools, and neighbors’ property all need thought, because the solution and runoff can reach them.

Safety first: chemicals, pets, children, and ladders

This is the part not to skip.

Never mix bleach with ammonia. The combination releases toxic chloramine gas. Ammonia is found in some glass cleaners and many other household products, so check labels.
Never mix bleach with vinegar or any acid (including rust removers and some toilet bowl or deck cleaners). The mix can release chlorine gas.
Do not combine different cleaning products unless the label explicitly says it is safe. Add products to your sprayer one at a time and rinse the sprayer between different products.
Wear protective gear. Splash-resistant eye protection, chemical-resistant gloves, long sleeves, and closed shoes are sensible. Follow the product label for any respirator guidance.
Work outdoors in good airflow and avoid windy days when spray can drift onto you, neighbors, or plants.
Keep children and pets away during mixing, application, and rinsing, and until surfaces and nearby grass or soil have been rinsed and are dry. Store chemicals locked up and out of reach in their original containers.
Use ladders carefully. Falls are a real risk when working with wet, slippery surfaces. Do not lean out from a ladder. Leave roofs and upper storeys to professionals.
Read the label and the safety data sheet for every product you use.

If you are not comfortable handling bleach, use one of the gentler options below or hire a professional.

What you need

A garden hose with a spray nozzle
A low-pressure sprayer (a pump garden sprayer is common for small jobs)
A soft-bristle brush on an extension pole for stubborn areas
Your cleaning solution (see below)
Plastic sheeting or bags and painter’s tape for covering outlets and fixtures
Eye protection, gloves, and protective clothing

What goes in a soft wash mix

Professional mixes typically combine three things:

A cleaning agent. Most often sodium hypochlorite, the active ingredient in household bleach. Professionals often use stronger commercial concentrations than household bleach, which is one reason this work is better left to trained people at that strength. Household bleach is weaker, so it is diluted differently.
A surfactant. A soap-like ingredient that helps the mix cling to vertical surfaces and lift dirt. Some people use dish soap or laundry detergent. Check that any detergent you choose contains no ammonia.
Water. To dilute to the intended strength.

The right strength depends on the product, the surface, and the amount of growth. For vinyl siding, commonly cited concentrations of sodium hypochlorite are low, around the range of one percent, but you should follow your siding manufacturer’s guidance and the label of the product you buy rather than a number from a web page. When in doubt, test a small hidden area first and start weaker.

Step-by-step: how to soft wash a house

Choose the day. Pick a mild, calm, overcast day if you can. Direct sun can make the solution dry before it works.
Clear the area. Move furniture, grills, toys, and vehicles away from the walls.
Protect the house. Close windows and doors. Cover outdoor electrical outlets, light fixtures, and doorbell cameras with plastic and tape.
Protect plants. Wet nearby plants and lawn thoroughly with plain water before you start, and again afterward. Cover delicate plants if needed.
Wet the wall. Lightly rinse the section you will clean with plain water.
Mix carefully. Prepare the solution outdoors according to the label, never in a closed space.
Apply from the bottom up. This helps avoid streaks. Work in small sections you can rinse before they dry.
Let it dwell. Leave the solution on for the time the label suggests, often several minutes. Keep it wet and do not let it dry on the wall.
Scrub if needed. Use a soft brush on stubborn spots.
Rinse from the top down. Use plenty of clean water. Rinse thoroughly, including window frames, trim, and the ground at the base of the wall.
Rinse plants and soil again.
Clean up. Rinse your sprayer and tools, and store leftover chemicals safely out of reach of children and pets.

Gentler alternatives to bleach

If you would rather avoid bleach, there are other approaches:

Dish soap and water with a soft brush removes light dirt and pollen, though it is not as effective on algae and mildew.
Oxygen bleach (sodium percarbonate) cleaners are marketed for exterior cleaning and are generally gentler on plants than chlorine bleach, but still need eye and skin protection and a thorough rinse. Check that the product suits your siding.
Products labeled specifically for house or siding washing give you instructions matched to the formula.

Do not assume that “natural” means harmless. Vinegar, for example, is an acid and can dull or etch some surfaces, and it must never be mixed with bleach.

Soft washing different surfaces

Siding is only part of the picture. Different materials in your yard call for different care:

Manufactured or natural stone needs gentle handling. See how to clean stone veneer.
Powder-coated aluminum railings are usually cleaned with mild soap and water, not strong chemicals. See how to clean powder coated aluminum railings.
Screened porches and lanais have aluminum frames and screens that can be harmed by harsh products. See how to clean a lanai.
Artificial grass near the house can be damaged by runoff and bleach. See whether artificial grass is easy to keep clean and rinse it well if any solution lands on it.
Patio furniture near the walls can be hit by runoff, so move it clear first and rinse it well afterward. See how to clean wicker patio furniture for washing it once the job is done.
Windows and screens get rinsed along with the walls. Afterward, how professionals clean windows covers spot-free glass.
Garage doors and aprons are often washed in the same session, and our guide on keeping a garage clean covers what to do inside.

Using a pressure washer for soft washing

A pressure washer can be used on a low-pressure setting or with a wide-angle nozzle, and some have a downstream injector that draws solution into the water stream. This can make the mix weaker at the wall than what is in the bucket, so follow the equipment instructions. Keep the nozzle at a distance and never use a narrow, high-pressure tip on siding, because it can force water behind the boards or damage the surface. If you are unsure about the setting, use a pump sprayer instead.

For tips on washing siding with higher pressure, note that many siding manufacturers advise against it; check their guidance first.

How much does professional soft washing cost?

Prices vary widely by region, house size, height, siding type, and how dirty the surfaces are. Because quotes differ so much, ask two or three companies for written estimates that spell out what is included, such as plant protection and rinsing. Also ask whether they are licensed and insured where required locally.

Common mistakes

Letting the solution dry on the wall
Skipping the pre-wet and rinse of plants
Cleaning in direct sun or wind
Mixing products without checking labels
Using high pressure on siding
Working from a ladder in an unsafe position
Ignoring the manufacturer’s care instructions

FAQ

What is the best soap for house cleaning? For light dirt, mild dish soap works. For algae and mildew, a product made for exterior washing is usually more effective. Whatever you choose, avoid products containing ammonia if bleach is involved, and follow the label.

Can I soft wash with just water and bleach? It will clean, but the mix may run off quickly without a surfactant. Remember the safety rules above, and never add other cleaners to it.

How do I power wash siding? Use the lowest pressure that works, a wide nozzle, and keep your distance. Many manufacturers recommend gentler approaches, so check your siding guidance.

How often should I wash my house? It depends on climate and shade. Many homes need it every year or two, but let the look of the surface guide you.