How to Wash a House: Beginner Guide to Vinyl Siding Cleaning

New to house washing? This step-by-step guide breaks down the safe and effective way to clean vinyl siding. From identifying common growths to taping outlets and applying solution, we walk you through every stage of the process using downstreaming. Let’s get started.

What Typically Grows on Vinyl Siding?

Over time, vinyl siding becomes a magnet for organic growth. Here are common contaminants:

• Algae: Greenish film, often on the north side of homes.
• Mildew: Appears gray or black and thrives in shaded areas.
• Mold: Typically black and stubborn—especially behind vegetation.
• Dirt and Spiderwebs: From nearby landscaping or windows.

Pre-Wash Instructions & Checklist

90% of a successful house wash is preparation. Before you pull the trigger (pun intended), run through this checklist:

1. Cover all electrical components: Use blue painter's tape to seal outlets, ring doorbells, cameras, and breaker boxes.
2. Remove or protect delicate items: Cushions, flags, furniture, umbrellas, and grill covers may discolor or spot—move or cover them.
3. Pre-wet vegetation: Grass, shrubs, and nearby trees should be thoroughly soaked to prevent chemical absorption.
4. Test for oxidation: Rub your finger across the siding. A chalky residue indicates oxidation, which is not removed with a standard house wash and should be listed as an upcharge.
5. Check for sunlight: If washing in direct sun, always pre-wet siding before applying solution to avoid flash drying.

House Washing Process

Let’s break it down into simple steps you can follow every time:

1. Mix Your Solution: Combine SH (Sodium Hypochlorite) with a surfactant like Elemonator in a 5-gallon bucket. Your downstream injector will dilute this to the proper 1% strength.
2. Pre-Wet Everything: Soak siding, vegetation, cars, and nearby surfaces with water before applying any chemical.
3. Apply Cleaning Solution: Switch to chemical feed. Begin applying from bottom to top to prevent streaks and ensure dwell time. Apply one elevation at a time.
4. Let Dwell: Allow the solution to dwell for 1–3 minutes. Never let it dry—rinse sooner if it's hot and sunny.
5. Rinse Thoroughly: Switch back to water and rinse from top to bottom. Maintain a safe distance to avoid disturbing oxidation.

Pro tip: Use a bypass injector to quickly switch between soap and rinse modes without walking back to your machine.

Before and After Photos

Watch the Full Tutorial

Quick Tips for Success

• Only wash one side at a time—never let soap dry on siding.
• Pre-wet black trim, doors, or painted accents to avoid spotting.
• Test surfaces for oxidation and set expectations with customers.
• Use the black soap tip or a J-rod to apply solution properly.
• Rinse thoroughly—especially windows, doors, and any vehicles.

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