How to Pressure Wash a House Like a Pro

Want your house to look freshly painted without actually painting it? A thorough exterior wash removes years of dirt, algae, mold, and grime to reveal the clean surface underneath. But here's what most homeowners don't realize: most houses shouldn't be pressure washed at all. They should be soft washed. Using the wrong method on your siding is one of the most common (and expensive) DIY mistakes in exterior cleaning.

This guide covers both methods — when to use each one, how to do it safely, and what to watch out for.

Pressure Washing vs. Soft Washing: Which Does Your House Need?

Before you rent a machine or hire someone, figure out what your house is made of. The exterior material determines the method.

How to Soft Wash a House (The Right Way for Most Homes)

Step 1: Protect Your Property

Close all windows and doors. Move outdoor furniture, rugs, and anything that shouldn't get wet away from the house. Pre-wet all landscaping, grass, and plants within 10 feet of the house. Cover particularly sensitive or valuable plants with plastic sheeting. Pre-wetting creates a barrier that dilutes any cleaning solution runoff.

Step 2: Apply Cleaning Solution Bottom to Top

Using a soft wash pump or a downstream injector on your pressure washer (with a low-pressure soap tip), apply the cleaning solution starting from the bottom and working up. Why bottom to top? If you start at the top, solution running down the dry siding below creates streaks. Applying from the bottom ensures even coverage.

Step 3: Let the Solution Dwell

The cleaning solution needs 10-15 minutes to work. It's killing algae, mold, and bacteria on contact. Don't let it dry — if the sun is baking a particular wall, mist it lightly with water to keep it damp. On hot days, work one wall at a time rather than treating the whole house at once.

Step 4: Rinse Top to Bottom

Rinse at low pressure (the same as a garden hose or slightly more) from the top down. This washes all the dead organic material and cleaning solution off the house and away from the siding. Work methodically — overlapping your passes so you don't miss strips. Pay extra attention under eaves, around windows, and behind downspouts where grime accumulates.

Step 5: Rinse All Landscaping

After the house is rinsed, thoroughly rinse all surrounding plants, grass, and hardscape. This dilutes any cleaning solution that reached the ground and ensures your landscaping stays healthy.

How to Pressure Wash a Brick or Stone House

If your house has brick, stone, or concrete block exterior, you can use pressure. But technique still matters:

• Use 1,500-2,500 PSI — you don't need the full 3,000+ PSI you'd use on a driveway
• Use a 25-degree or 40-degree fan tip — never a zero-degree tip on any house surface
• Pre-treat with a cleaning solution for best results
• Keep the nozzle 12-18 inches from the surface
• Work top to bottom so dirty water flows down and away
• Avoid mortar joints at close range — pressure can erode old or soft mortar
• Never pressure wash painted brick — use soft washing instead

Common House Washing Mistakes

• Pressure washing vinyl siding — cracks it, forces water behind it, and voids warranties
• Using a ladder with a pressure washer — the kickback from the wand can knock you off balance. Soft wash from the ground with extendable nozzles instead
• Spraying directly at windows — high pressure can crack glass and destroy seals
• Ignoring electrical outlets, light fixtures, and vents — cover them or avoid spraying directly at them
• Washing in direct sunlight on a hot day — the cleaning solution dries before it can work
• Skipping the landscaping protection — chemical runoff can burn or kill plants
• Starting at the top when applying solution — causes streaks on the dry siding below

How Often Should You Wash Your House?

In the SC Midlands, every 1-2 years is the sweet spot. Our warm, humid climate promotes fast growth of algae, mold, and mildew on exterior surfaces. North-facing walls and shaded areas get dirty fastest. If you're noticing green or black discoloration on your siding, it's time — waiting longer just means more buildup and a harder (more expensive) cleaning job.

DIY vs. Hiring a Professional

House washing is one of the services where hiring a professional makes the most sense. The equipment for proper soft washing (pump system, chemical injection, extendable nozzles) costs more than a single professional cleaning. The risk of damage from improper technique is high — cracked siding, water damage behind walls, and dead landscaping. And a professional can typically wash a full house in 1-2 hours, while a DIY job takes most of a day.

Professional house washing typically costs $200-$600 depending on home size. That's a small price for a service that protects your siding, preserves your paint, and makes your home look brand new.