Power Wash a House: What the Pros Actually Use

Ever seen a crew blast years of grime off a house in just an hour? It looks simple, but there's real science (and muscle) behind what they do. The machines professionals use aren’t the bargain ones you spot at big box stores. They pack way more punch, pushing water out at pressures that strip away gunk and mold in seconds.

Most pros choose gas-powered pressure washers, often with at least 3,000 PSI (pounds per square inch) and 3 GPM (gallons per minute) for tough siding jobs. That combo cuts cleaning time and gets deeper results. Electric models just can’t match that, especially when you’re dealing with stubborn mildew or baked-on dirt after a tough winter.

Next, it’s all about the right attachments. The wrong nozzle can gouge up your wood or vinyl, while the right one makes your siding look new. That’s why you should always start low and adjust up, never the other way around. If you’re thinking about trying it yourself, size up your gear first—every job (and every house) has its own sweet spot.

• Pro-Grade Pressure Washers: What Sets Them Apart
• Key Nozzles and Tips Pros Swear By
• Must-Have Detergents and Soaps for a Deep Clean
• Other Gear: Hoses, Extensions, and Safety Tools
• The Pro Cleaning Process: How They Work Fast and Safe
• Should You Rent or Call a Pro? What to Consider

Pro-Grade Pressure Washers: What Sets Them Apart

The stuff pros use isn’t just bigger and louder—it’s built to handle serious work all day long. When you see a high-end pressure washer in the back of a truck, you’re looking at a whole different class of machine. These things put out way more pressure and water flow than what you find in a DIY kit from the hardware store.

The biggest difference comes down to PSI (pounds per square inch) and GPM (gallons per minute). Here’s what usually separates pro units from those for casual home use:

• Pressure Washing Pros: Most use machines that push out 3,000 to 4,000 PSI. That’s a huge leap from the 1,800-2,000 PSI on most consumer models.
• Flow Rate: Pros want at least 3-4 GPM to wash away the loosened muck in one go. DIY units might only do 1.5 GPM and take longer to rinse.
• Gas Powered Engines: Most pro gear runs on gas, which means more power and no worries about tripping breakers or running out of cord. These engines last longer, too.
• Induction Motors: Pro washers usually have heavier-duty induction motors, which means less wear and tear and fewer breakdowns over time.
• Heavy-Duty Pumps: Commercial units use triplex or belt-drive pumps, not the cheaper axial types in regular washers. These last thousands of hours instead of just a couple hundred.

Here’s a quick breakdown to show just how much more juice pro models have:

So why don’t most folks own a pro-grade washer? They’re heavy, not cheap (think $800 and up), and they need real upkeep. For pros, though, it’s the only way to work fast without repeat passes, and to handle every surface—from battered old brick to delicate wood siding. The difference in result is huge; you can see it with every clean, streak-free swipe across the house.

Key Nozzles and Tips Pros Swear By

Choosing the right nozzle is a bigger deal than most people think. It can mean the difference between a squeaky clean house and wrecked siding. Every color-coded nozzle has a job, and pros know which ones to grab for every part of the job.

• Red (0°): Fires a pinpoint stream. It’s rare for pros to use this on a house—too much risk of damage, especially on wood and vinyl. Sometimes used for blasting stubborn stains on concrete.
• Yellow (15°): Good for heavy-duty stripping but still risky for siding. You'll see it more often on driveways or brick steps.
• Green (25°): This is the go-to for most house washing. It’s strong enough to lift dirt and mold but wide enough to be safe for siding.
• White (40°): Super gentle. Perfect for windows, screens, and painted surfaces. Some pros use this nozzle for a final rinse to avoid streaks on vinyl.
• Black (Soap): Sends out low pressure to let detergent soak into the grime before rinsing.

Attachment tips aren’t just about the spray pattern. Pros use extension wands to reach two stories, and surface cleaners for decks and patios to avoid tiger stripes. There's also the turbo nozzle, which spins a zero-degree spray in a circle—super effective, but only for brick or concrete.

Here’s a quick cheat sheet on common nozzles and their typical uses:

The main thing pros keep in mind? You want to start with the least aggressive tip that does the job. If you’re ever feeling unsure, stick with white or green. And always spray at an angle—never straight into soft siding or gaps. That keeps water out of places it shouldn’t go, like under the trim or behind shutters.

Must-Have Detergents and Soaps for a Deep Clean

If you want results like the pros, it’s not just about blasting water everywhere. They always use special detergents made for power washing. These are way better than your average household cleaners because they're designed to break down dirt, mold, algae, and even those sticky cobwebs you can never seem to fully remove.

The most common types you'll find in a pro’s truck are:

• House and siding detergents – Formulated to lift grime, tree sap, and dirt from wood, vinyl, and stucco, without damaging the finish.
• Mold and mildew removers – Packed with mildewcides and surfactants, these attack fungus on shady, damp areas.
• Degreasers – Ideal for spots under eaves or in garages where oil and grease love to hide.
• Environmentally safe soaps – When you’ve got pets, gardens, or just want to play it safe, there are plenty of biodegradable picks that still work hard.

Here’s a quick look at what the pros often choose for different messes:

Using the right soap isn’t just about good looks. It can actually help prevent damage. For example, using a mold remover on areas that always get damp means you’ll slow down new growth, and you won’t have to wash again as soon. Also, most pro-grade soap concentrates are made to go straight through pressure washing machines without harming pumps, hoses, or siding.

Pro tip: never use bleach unless the label says it’s safe for your surface. Straight bleach can wreck paint, kill plants, and eat away at your gear. If in doubt, test a small spot first.

Other Gear: Hoses, Extensions, and Safety Tools

Pressure washers don’t do the heavy lifting alone. Professionals carry a lineup of must-have accessories that make big cleaning jobs faster, safer, and just plain doable. Let’s face it: pro jobs are full of ladders, obstacles, weird angles, and hard-to-reach grime.

The hose is no place to cheap out. Pros use non-marking, heavy-duty hoses—usually rated for at least 4,000 PSI. Those gray or blue hoses you sometimes see are built to handle high pressure without kinking like a garden hose. Most standard setup comes with 50 feet, but pros snap multiple hoses together to reach all sides of a big house without constantly moving their rig.

Extensions and wands are another secret weapon. Telescoping wands stretch 12–24 feet (sometimes even more), so you can clean second stories from the ground. That means less time on ladders, which is a huge deal for safety. Some pro setups use pivoting couplers to hit awkward spots—like under eaves—without twisting your arm off.

Safety is no joke with this much pressure. Professional crews always wear PPE (personal protective equipment), including:

• Goggles or sealed safety glasses (no one wants a dirt chunk in their eye at 3,000 PSI)
• Rubber gloves for chemical protection
• Sturdy boots with grip (soapy surfaces get slick fast)
• Hearing protection, especially for gas-powered pressure washers

Here’s a quick peek at typical gear you’ll spot on any serious pressure washing job:

Skipping any of these just isn’t worth a hospital trip or a half-clean house. If you’re getting prepped for a big clean, stock up on real pro-grade gear before firing up that pressure washer.

The Pro Cleaning Process: How They Work Fast and Safe

Watching a pro clean a house isn’t just about blasting water everywhere. The best guys follow a proven order so nothing gets missed (and nothing gets wrecked). Here’s how the pros break it down:

1. Prep and Safety Check: First thing—move furniture, cover electrical boxes, tape up outlets, and check windows are closed tight. Safety glasses go on before that wand comes out. Pro tip: Walk around the house and spot any loose siding or damage before starting. This saves you a big headache later.
2. Detergent Soak: Pros don’t just spray; they use a cleaning solution that lifts dirt and kills mildew. Most use a low-pressure nozzle to coat the house from bottom to top, which avoids streaks.
3. Dwell Time: Letting the soap sit for 5-10 minutes makes a big difference. This soak breaks up grime so it rinses right off.
4. Rinse, Top to Bottom: Next, they grab a higher-pressure nozzle and rinse everything, working from the roofline down. Always rinse windows last to avoid spots.
5. Spot Check and Touch Up: If any spots refuse to budge, pros use a soft brush or try a tighter nozzle for a second pass. No rushing—details matter.

What makes pros fast? Experience and equipment. With a crew of two, a 2,500-square-foot house usually gets done in under two hours. Solo? Give it three, tops. They don’t drag their feet because they know exactly where things slow down—like around screened porches and railings. They also use extension wands on two-story houses so they don’t need to mess with ladders every five minutes.

One essential rule: never point the stream up under the siding. Water behind the boards can lead to mold, rot, or some wild repair bills. As Kevin Farrell, a certified pressure wash instructor, puts it:

“Downward angles are the golden rule. You protect every bit of siding and never risk water sneaking inside.”

It’s not just about speed, though—accidents from high-pressure equipment are for real. OSHA reports that about 6,000 pressure washer injuries show up in U.S. ERs every year, plenty from people trying to reach tricky spots by overreaching or skipping safety steps. Pros keep both feet on the ground whenever possible, and their gear has built-in stops so wands don’t jerk suddenly if a hand slips.

That’s the pro playbook: fast, smart, and safe. Following these steps with the right equipment is what separates a spot-free house from a risky weekend project.

Should You Rent or Call a Pro? What to Consider

Deciding between renting equipment and bringing in a professional comes down to time, safety, your house’s condition, and your comfort level with heavy gear. Before you haul a giant pressure washer home from the rental shop, it’s good to weigh the real-world pros and cons.

If you rent, expect to pay around $50–$100 a day for a basic model. The ones most rental stores offer top out at around 2,400 PSI—good for cars, decks, and some siding, but not the serious stuff. On top of that, you’ll likely need a deposit and to buy your own soap. You also have to be honest about your stamina: using a washer for hours can be exhausting if you’re not used to it.

Professionals, on the other hand, bring gear that’s tougher and faster, like commercial units with over 3,000 PSI and accessories that let them reach high or awkward areas. Most cleaning companies are insured, so if anything goes wrong (think broken windows, wood splinters, or water in places it shouldn’t be), you’re covered. And for tough mold or high, two-story houses, it’s safer. No ladders, less risk to you.

Here’s a quick look at the tradeoffs:

If your home’s siding has stubborn stains, or if the last time you cleaned was years ago, pros usually get better results. Renting makes sense for smaller jobs or if you’ve got time to learn the ropes (and don’t mind a wet afternoon). Whatever you pick, test a small hidden area first. And remember, strong pressure washing can do real damage fast—better safe than sorry with old paint or delicate surfaces.