Soft washing is how most professionals clean siding, and it is the service that separates a pressure washing company from a guy with a pressure washer. Instead of blasting the dirt off with pressure, you apply a diluted cleaning solution at low pressure, let it kill and loosen the mildew and algae, and rinse it away. Done right, the house looks new and nothing gets damaged. Done wrong, you strip paint, burn shrubs or force water behind the siding. This post walks through the process, the mixing basics, plant protection, the order of work and what to tell the customer before and after.
Why Low Pressure on Siding
Vinyl, painted wood, fiber cement and stucco do not need high pressure to get clean, and most of them are harmed by it. High pressure forces water up behind lapped siding, into window seals and soffit vents, and through cracked caulk. It can etch soft wood, chip paint and leave visible wand marks. On older vinyl it can crack brittle panels.
The green and black on most houses is organic growth: mildew, algae and mold. Pressure moves it around; it does not kill it, so it grows back fast. A cleaning solution kills it at the root, which is why a soft washed house usually stays clean longer than one that was blasted.
That is the pitch to the customer, too. "We clean siding at low pressure with a solution that kills the mildew, so we do not damage the siding and it stays clean longer." Most homeowners have heard a horror story about someone who stripped a neighbor's paint, and they appreciate the explanation.
Mixing the Solution Safely
Most house wash mixes are built on sodium hypochlorite (the active ingredient in bleach, sold to pros at higher strength), diluted with water and paired with a surfactant that helps it cling to the wall and break down grime. The right strength depends on the surface and how dirty it is. Light mildew on vinyl needs a weaker mix than heavy algae on the shady north wall.
Follow the label and the manufacturer's guidance for every product you use, and start weaker rather than stronger. A mix that is too strong can damage plants, fade some finishes and irritate the crew's skin and eyes. Wear eye protection and gloves when mixing, mix in a ventilated spot, and never combine chlorine products with acids or ammonia.
Write down what you used. Recording the product and mix on each visit, along with notes about how well it worked, means next year's crew starts with what worked on that house instead of guessing. If you track product mixes with rates in the software, the crew can log the mix and amount used on the visit from the phone.
Protect the Plants, the Customer's Stuff and Yourself
Plant damage is the most common soft washing complaint. Chlorine runoff can brown leaves and burn tender plants, especially on hot days. The routine is simple and it works: wet the plants thoroughly before you apply solution, keep them wet while you work, and rinse them again afterward. Some crews also use a neutralizing product on landscaping. Cover delicate plants or move potted ones away from the wall.
Look around before you start. Close windows and doors (the night-before text should ask the customer to do this, but check). Move patio furniture, grills and toys away from the walls. Cover outdoor outlets and light fixtures, or at least be careful around them. Note cars parked close to the house; mist drifts.
Check the wind. If it is gusty, mist will carry onto cars, windows and the neighbor's house. Many crews will not soft wash a house in steady wind, and it is a reasonable rule. Moving the job a day costs much less than repainting a neighbor's car trim.
Work the House in Order
A consistent order prevents missed spots and streaks. A common approach: start on the shady side of the house, wet the plants, then apply solution from the bottom of the wall up. Applying bottom to top keeps the solution from running down dry siding and leaving streaks. Let it dwell for a few minutes (keep it from drying on the wall) and rinse from the top down at low pressure.
Do soffits and the underside of eaves as part of each wall, and check the gutter faces. Black streaks on gutters are often oxidation and road film, which a standard house wash does not fully remove. If you offer gutter brightening as an add-on, this is where it comes up.
Rinse the windows well at the end so they do not dry with spots. Walk the house when you finish, looking up at the corners and under the eaves. Missed spots almost always hide in the same places: behind downspouts, above doors and in the corners of the porch ceiling.
Prep the Customer Before and After
The customer has a few jobs: close the windows, move cars away from the house, keep pets inside, make sure the outside spigot works and leave the gate open. Put all of that in the night-before text so it is in writing. A customer who left a window open and got a wet bedroom is less upset when they can see they were asked to close it.
Set expectations about what soft washing does not do. Rust stains, irrigation stains and oxidation on old vinyl or aluminum siding do not come out with a standard wash. Chalky, faded siding may look more uneven after cleaning because the dirt was hiding the fading. Tell the customer before you start, not after.
After the job, send photos. A completed alert with before and after photos and a short note ("All four sides, soffits and gutters exterior washed, plants rinsed before and after") does two things: it shows the customer what they paid for, and it creates a record if someone later claims a plant died or a window was damaged. The crew takes the photos on the crew app during the visit and the alert sends them out when the job is marked done.
Turn the First House Wash Into a Yearly One
A house that was soft washed properly usually looks good for a year or more, depending on shade, trees and climate. That makes house washing a natural yearly repeat. Most customers would rather be reminded than have to remember.
Offer the repeat at the end of the job, while the house looks great. A small discount for booking the yearly wash in advance is an easy yes. Set it up as a recurring service every 365 days and next year's wash comes due on the Waiting List on its own, with this year's notes, mix and photos on the property. Our post on turning one-time washes into recurring customers covers how to price and schedule repeats.
If the customer is also a lawn customer, mention the house wash in the same message as spring lawn service. Customers who already trust your crew on their property are the easiest house wash sales you will make. The pressure washing hub shows how wash work and lawn work share one customer list.
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