Pressure washing your home may seem simple — just aim and spray, right? Not so fast. To pressure wash a house, you’ll need the right equipment, the correct nozzle and technique, and a careful approach to avoid damage.
I spoke with my colleague Sarah, whose dad has years of experience pressure washing their family home. Growing up, Sarah learned firsthand that technique and safety matter just as much as power.
From choosing the right spray pattern to avoiding costly mistakes, this guide (backed by the experience of Sarah and her father) will walk you through the process step by step, so you can clean your home safely and effectively.
| Project difficulty: Easy to Intermediate Estimated time to complete: 20 to 30 minutes per section, 1.5 to 6 hours for whole house (depending on size) Drying time: at least 48 hours (especially before painting or staining) Project cost: $20–$100+ (depending on equipment rental and supplies) |
Supplies Needed
Before you begin, prepare the necessary tools and materials:
- Pressure washer (gas or electric, depending on your needs)
- Nozzles (soap nozzle, 25-degree, and 40-degree tips)
- Detergent (optional, mildew-resistant recommended)
- Garden hose (for water supply)
- Soft-bristle brush (for stubborn stains)
- Safety gear (goggles, gloves, long sleeves, ear protection, closed-toe shoes)
- Plastic covers, duct tape, tarp, and drop cloths (to protect nearby objects)
- Extension wand (if needed for higher areas)
How to Choose the Right Pressure Washer
Not all pressure washers are created equal. Choosing the right one depends on your home’s exterior, the size of the job, and how frequently you plan to use it. Here’s how to decide:
Gas vs. Electric
- Gas-powered washers: More powerful and ideal for large surfaces, while electric models are lighter and suited for smaller areas. They typically have 2,500+ PSI (pounds per square inch) and a higher GPM (gallons per minute).
- Electric-powered washers: Lighter, quieter, and great for smaller jobs. These usually have 1,200 to 2,000 PSI and are easier for beginners to handle.
Sarah’s dad, who has years of experience with DIY pressure washing, recommends gas-powered models for cleaning concrete driveways and brick walls because they offer better power and durability. He notes that electric models work well for light-duty tasks but are generally less sturdy.
PSI and GPM
- A higher GPM means more water is used, which improves cleaning efficiency. Look for a model with at least 2.3 GPM.
- For house exteriors, a pressure washer with a minimum of 2,600 PSI is recommended. However, use lower PSI (1,200 to 1,600) for delicate surfaces like wood and aluminum siding to avoid damage.
Buying vs. Renting
If you plan to pressure wash yearly, buying is a good investment. Rentals cost around $38 to $42 per day, while a decent pressure washer costs an average of $246 (it depends if gas or electric powered).
How to Prepare Your House for Pressure Washing
Jumping straight into pressure washing without preparation can lead to damage, water getting into unwanted places, or missing spots that need extra attention. Spend time getting everything set up properly, and the actual cleaning process will go much smoother. Here’s how to prepare:
- Wear protective gear: Pressure washers are powerful, and water at high pressure can cause injury. Wear safety goggles, gloves, long sleeves, ear protection (a tip from Sarah’s dad), and closed-toe shoes to protect yourself.
- Move or cover furniture, plants, and outdoor decorations: Use plastic sheeting or tarps to cover delicate plants and anything that could be damaged by the water pressure.
- Close all windows and doors: Even small gaps can let water seep inside, potentially damaging walls and floors.
- Cover electrical outlets, doorbells, and light fixtures: Use plastic and secure it with duct tape to keep everything dry.
- Trim overgrown plants or shrubs: This will prevent them from getting in the way while you work.
- Pre-soak the surface with detergent: This will help loosen dirt, mold, and mildew so it washes away more easily.
- Scrub problem areas: If you notice stubborn stains or mildew, use a soft-bristle brush to work in the detergent before rinsing.
Steps to Pressure Wash a House
Step 1: Set Up the Pressure Washer
- Connect the garden hose to your pressure washer.
- Attach the spray wand and choose the right nozzle. If using detergent, go with a soap nozzle (usually black).
- If using detergent, fill the detergent tank with a pressure-washer-approved cleaner.
- Important: Sarah’s dad emphasizes never starting the pressure washer without first turning on the water supply. Doing so can burn out the pump (especially in gas models), leading to costly repairs.
- Test the washer on a small, hidden section before starting to ensure the pressure isn’t too strong.
- According to Sarah’s dad, gas pressure washers have a strong kickback when you pull the trigger, so maintain a steady stance and hold the wand with both hands.
Tip: If you’re using an electric pressure washer, plug it into a GFCI-protected outlet to avoid electrical hazards.
Step 2: Apply Detergent (Optional)
Skip this step if not using detergent.
Applying a detergent can help loosen stubborn dirt, mildew, and algae, especially if your home hasn’t been cleaned in a while.
- Start at the bottom of the house and work your way up to prevent streaks.
- Use slow, sweeping horizontal motions to ensure even coverage.
- For higher areas, attach an extension pole and keep the spray at a downward angle to prevent water from seeping behind the siding.
- If you see any problem spots, use a soft brush to gently scrub the surface clean.
- Let the detergent sit for 10 to 15 minutes to break down dirt and mildew.
Tip: Avoid letting the detergent dry on the surface. Keep an eye on sunny spots where it may evaporate quickly.
Step 3: Switch to a Rinsing Nozzle
- If using detergent, swap the soap nozzle for a 40-degree or 25-degree nozzle.
- For a general clean, use a 40-degree nozzle (white).
- For tougher spots, a 25-degree nozzle (green) will give you more power.
- If not using detergent, start washing with the 25-degree or 40-degree nozzle immediately.
Step 4: Rinse/Wash the House
- Keep the nozzle 2 to 3 feet away from the siding. Move closer, in small increments (around 4 to 6 inches), if needed.
- Start at the top of the house and work your way down to rinse away detergent and dirt.
- Use even, side-to-side motions to avoid damage.
- Clean the overhangs and gutters first, maintaining a 45-degree angle, then you can move on to the siding.
- Be cautious around windows, vents, and soft surfaces.
See Related: How to Pressure Wash a House With Vinyl Siding
Step 5: Clean Up
- Turn off the pressure washer and disconnect the hose.
- Remove protective coverings from plants and electrical outlets.
- Let the house dry for at least 48 hours before painting or staining.
How to Use a Pressure Washer Safely
Pressure washers are powerful tools, and improper use can cause injury or property damage. Follow these safety tips:
✔ DO:
- Test the washer on a small area first.
- Keep the nozzle moving constantly to prevent damage.
- Use low-pressure settings for delicate surfaces.
- Check surroundings for power lines, children, or pets before starting.
✗ DON’T:
- Never refill a gas-powered pressure washer while the engine is hot (an important reminder from Sarah’s dad).
- Never aim the pressure washer at people, pets, or glass windows.
- Avoid spraying into cracks, vents, or electrical outlets.
- Don’t use a pressure washer while standing on a ladder. The recoil can cause you to lose balance.
When It’s Best to Soft Wash Your House Instead
Not all surfaces can handle high-pressure cleaning. Soft washing uses low-pressure water and specialized cleaning solutions to remove dirt and mold.
When to Soft Wash
- If your home has vinyl, stucco, or wood siding.
- If you’re concerned about paint damage or cracks.
- If you’re cleaning delicate surfaces like roofs or shingles.
FAQ
For general house washing, use a pressure-washer-approved detergent. Many contain a mix of surfactants and mild bleach to remove dirt, mold, and mildew.
You can also consider the following cleaning solutions:
• 1 part bleach with 10 parts water
• a diluted vinegar solution (70% water, 30% vinegar)
Typically, the recommended PSI when pressure washing is from 1,300 to 3,000. But the ideal PSI depends on your surface or siding material:
• Vinyl or aluminum siding: 1,300 to 1,600
• Wood surfaces: 500 to 1,200 (start low to prevent damage)
• Stucco: 1,200 to 1,500
• Brick and stone: 500 to 2,000 (be careful around mortar)
• Concrete driveways and walkways: 2500 to 3000
Keep in mind: Using too much PSI can crack stucco, strip paint, and even dent vinyl.
It is recommended to stick with a 25-degree or 40-degree nozzle for best results. However, it will still depend on the surface you’re cleaning. The nozzle tip determines the spray angle and pressure. Here’s a quick guide to the most commonly used system:
🟢 Green (25°): Great for general house washing.
⚪ White (40°): Ideal for delicate surfaces like windows or painted siding.
🔵 Black (Soap nozzle): For applying detergent (low pressure, wide spray).
🔴 Red (0°): Do NOT use on siding (it’s too powerful and can cause damage).
Note: Some manufacturers may not follow this same system. Familiarize yourself with the operating instructions before using any power washer.
The amount of water a pressure washer uses depends entirely on the brand, model, and manufacturer.
On average, most standard residential pressure washers operate between 2 to 4 GPM. Over the course of an hour, that adds up to 120 to 240 gallons of water.
However, high-end units can operate at 8 to 20 GPM, requiring massive water tanks and often mounted on trailers for mobility. But these machines are designed for large-scale jobs, like cleaning commercial buildings or heavy equipment.
A Clean Home, Done Right
In pressure washing your house, the right tools, technique, and a few safety tips can make all the difference between a job well done and a costly mistake. Luckily, Sarah’s dad has been through it all and shared some must-know advice, like why you should always turn on the water before starting the machine unless you want to burn out the pump.
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Main Image Credit: Victor / Adobe Stock Free / License
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