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Pressure Washing 101: A Definitive, Beginner-Friendly Guide

Table of Contents

Before and after results of walkway pressure washing.

Published by: CA WASH PROS
Last Updated: 2025-12-09

When it comes to exterior cleaning, pressure washing always works wonders and never disappoints. The whole process is simple, quick, efficient, and transformative.

Pressure washing removes different types of buildup that accumulate in exterior surfaces.

In the Bay Area, pressure washing can be done all year round so you can keep your outdoor surfaces clean, pristine, and well-maintained regardless of the season.

In this blog, we’ll walk you through everything about pressure washing: what it is, types of pressure washers, applications, nozzles and accessories, do’s and don’ts, and professional services and pricing.

Key Takeaways

  • Pressure washing uses high water pressure to remove a variety of buildup and stains.
  • Gas-powered pressure washers are for commercial use.
  • Electric-powered pressure washers are for household use.
  • The material of the surface determines the pressure level it can handle.
  • Always read the owner’s manual and exercise caution when using a pressure washer.
  • In the Bay Area, professional services are in high-demand all year round.

Pressure Washing Definition

Pressure washing is essentially spraying high water pressure on a sturdy surface to deliver a quick and efficient clean that removes buildup, stains, and bio-organism growth like moss and algae.

Pressure washing and power washing are interchangeable terms. We’ll use both terms to mean the same thing.

Benefits of Pressure Washing

  • Increases curb appeal instantly
  • Eliminates ground-in buildup and stains
  • Delivers quick and efficient cleaning with less time and effort
  • Extends the lifespan of the surfaces

Buildup Pressure Washing Can Remove

  • Dust
  • Dirt
  • Bird droppings
  • Moss*
  • Algae*
  • Mold*
  • Lichen*
  • Mildew*
  • Oil*
  • Grease*
  • Rust*
  • Paint*
  • Graffiti*
  • Efflorescence/calcium*
  • Water stains*
  • Spiderwebs*

*May require additional cleaning solution to fully remove

Patio pressure washing before and after results.

Pressure Washers

We can categorize pressure washers based on power source: gas and electric. Let’s compare and contrast.

Gas-Powered Pressure Washer

A gasoline-powered unit produces higher energy output. It is more powerful it is not restricted by the amperage of the electric outlet. The portability is better.

A gas-powered pressure washer could create loud noises and exhaust fumes. It is ideal for large-scale projects and commercial uses.

Electric-Powered Pressure Washer

Electric-powered pressure washers require consistent connection to an outlet. They produce less noise and do not exhaust fumes.

While they have less power than gas-engine units, they are still effective for smaller projects and household uses. Portability is limited to the length of wire. 

Professional Insights: Gas-Powered vs Electric-Powered Pressure Washers

The main difference is that the electric-powered unit does not generate the same force that a gas-powered unit does.

Typically, electric-powered pressure washers are more for residential consumers that want to pressure wash a car or do minor pressure washing projects.

It’s not recommended to try to pressure wash a driveway with an electric unit because it’s going to take a very long time and the quality would not be that great. 

Compared to a gas-powered unit, it’s like cleaning something with a small toothbrush versus with a large broom.

Factors that Determine Cleaning Rate and Quality

There are also smaller gas-powered pressure washers that are as equally as weak as electric ones.

What really determines the quality and rate of cleaning is the psi (pound per square inch) times the gallons per square unit. The higher the gallon per minute, the more it puts out water and the faster it cleans.

Most residential pressure washers are underneath 2 gallons a minute with the highest from what we’ve seen being at 2.2 gallons a minute.

For commercial pressure washers, the smallest one that we would use is 4 gallons a minute. There’s at least no electric pressure washer that we know of that equals that output.

Buying Guide

Here’s a quick guide to help you determine what type of pressure washer you need.

Electric-powered

  • For smaller projects and occasional convenient uses
  • Minimal maintenance required

Gas-powered

  • Best possible quality and cleaning results
  • Must check local regulations first
  • Units that sit in an extended period of time requires maintenance

Important Things to Consider:

  • Some cities in California, particularly in the Northern part, are banning all small engines so you can’t even purchase gas-powered pressure washers. If you do, you can get fined. Double check the specific regulations in your city when it comes to small engines before buying.
 
  • Your pressure washer (whether gas or electric) should be compatible with different types of attachments because you rarely just want to clean with the standard colored tips. There are instances when an electric-powered unit is not compatible with devices that you can attach to gas-powered units.
 
  • Identify the attachments that you need before purchase. There are a variety of fittings for different surfaces such as surface cleaner, x-jet, telescopic wand, and more.

Applications: Materials You Can and Cannot Pressure Wash

Can Pressure Wash

In general, these exterior surfaces can be pressure washed. The type of material determines how much pressure the surface can handle.

  • Driveway, Walkway, Sidewalk
  • Walls and Siding
  • Deck and Patio*
  • Wood Fence and Pergola

 

*Certain type of materials need extra care or can’t be pressure washed

Concrete
Driveways
Flagstone
Siding and Walls
Patio
Wood Deck
Pergola

Caution in Pressure Washing

Pavers

Pressure washing will likely remove the sand within the joints. The more it’s been washed before, the more sand can come off since there are more gaps in the joint.

Some Deck Types

There are some decks we don’t recommend pressure washing, but more so recommend applying a chemical solution and then brushing because pressure washing can be more harsh on that type of surface and shorten its lifespan.

Contact the deck manufacturer for specific cleaning guidelines.

Cannot Pressure Wash

Asphalt

Close up high pressure wash can cause scarring and markings. Asphalt is an extremely soft material and pressure is going to rip it off. If you want the asphalt to look brand new, you might consider a resurface service instead.

Aggregate Patio

For patios, one type we don’t recommend pressure washing is aggregate. A lot of little pebbles will come loose when you pressure wash aggregate.

Pressure Washer Accessories: Nozzles and Attachments

Pressure washer accessories are not universal. Some devices can only be attached into gas-powered pressure washers and not on electric-powered units.

Make sure to read manufacturer’s guidelines for compatibility. Incorrect fittings may affect cleaning performance and potentially damage the machine.

Pressure Washer Nozzles

Standard pressure washer nozzles are categorized in colors that specify the use, degree, and capacity.

Red - 0°

  • Highly concentrated stream of water for tougher stains and deep cleaning
  • Powerful and direct
  • Can easily damage delicate surfaces
  • Use with caution

Yellow - 15°

  • Medium-intensity pressure washing
  • Can remove old paint
  • Can damage siding if sprayed too long

Green - 25°

  • General-purpose and most commonly used
  • Most recommended for first time use
  • Covers large areas fast
  • Very effective for removing mud or dirt on vehicles and household furniture

White - 40°

  • Best for gentle cleaning of delicate and fragile surfaces like glass, windows, and freshly painted surfaces
  • Lower pressure and very wide spray pattern
  • Less risk of damage

Black - 65°

  • Also known as detergent or soaping tip nozzle
  • For applying detergents and cleaning solutions
  • Ideal for soaking the surface before pressure washing

Common Pressure Washing Attachments

Surface cleaner attachment for pressure washers

Surface cleaner

A surface cleaner is a large disc-shaped equipment specifically used for washing floors. It has a round head with rotating spray bars for quick and even cleaning. You’ve probably seen one in videos about pressure washing floors and driveways.

Telescoping Wand

The telescoping wand is your partner in cleaning hard-to-reach areas like windows and siding. It’s an extended lance that allows you to keep your feet on the ground while pressure washing surfaces in higher stories.

Xjet

An x-jet attachment allows you to spray chemicals and cleaning solutions without running them through the pump itself. It’s very popular in soft wash methods.

It’s used in house washing and wood pressure washing because the x-jet runs the pressure down. It prevents scarring of the wood, stripping of pain, and tearing off stucco on homes.

Types of Buildup and Cleaning Solutions to Remove Them

Bio-organisms growth (moss, algae, mold, mildew, lichen)

The biocide treatment is a very mild bleach mixture used to kill or neutralize any of the bio organisms that the initial pressure washing did not remove.

Pressure washing outdoor stairs to remove moss and algae buildup.

Oil Spills

First, you need to use hot water since cold water can not properly loosen it. You’re going to need a degreaser to pull oil from the concrete because pressure washing only cleans the surface level. If the oil has worked its way too deep on the surface, it might be impossible to fully remove it.

Oil spill treatment on a driveway - before and after.

Rust

Rust is natural so it grows and spreads over time. You’re going to need a heavy duty cleaning solution like an F9 Barc rust remover. The longer the rust has been there, the less likelihood of removing it.

Efflorescence on Brick

It is common for bricks to have efflorescence or calcium buildup, which appears as white haze or streaks. Pressure washing alone is not enough to remove this and you’ll need a specific chemical to break the molecular bond and remove the calcium buildup.

Results of house wash service by CA Wash pros on a brick siding to remove mold and dirt buildup.

Paint and Graffiti

Pressure washing paint and graffiti doesn’t always need chemicals but there are instances when you’ll need some to fully remove it.

Pressure Washing Do’s and Dont’s

DO’s

Wear Protective Gear

Safety glasses, long sleeves shirt, gloves, closed-toe rubber-soled shoes

Ensure Proper Set up

For electric-powered pressure washers, test the ground fault circuit interrupter (GFCI) before using. Secure the plugs and and keep power cords out of standing water and away from runoff.

Make sure the parts and accessories are properly attached. Always read the owner’s manual for specific guidelines.

Test it First on an Unseen Spot

Start with low settings and wider angles and spray out on a hidden spot. Gradually increase until you’re comfortable in using it.

Determine the suitable setting and attachment for the surface you’re washing and do a test run.

Always maintain a safe distance of at least 3 feet away from the surface and hold 3 seconds maximum on one spot.

DON’Ts

Don’t Point or Spray At People, Animals, and Plants

Never point or spray the pressure washer at yourself, others, animals, and plants as it can cause serious injuries and destroy plants.

Don’t Use Gas-Powered Units In Enclosed Spaces

There’s a risk of carbon monoxide poisoning when using gas-powered pressure washers on enclosed spaces or areas without proper ventilation.

Don’t Allow Children To Operate The Machine

Always keep children at a safe distance when pressure washing and never let them operate the unit.

Don’t Touch Electrical Cords and Outlets When Using

Avoid unplugging the power cord when still in use. Turn the switch off first. Allow the machine to dry before storage.

Safety Tips: Risks of Injury in Pressure Washing

  • Strong water pressure can cause serious wounds
  • High water pressure can dislodge objects and hit others in the surrounding
  • Electric shock can occur from incorrect setup and loose wiring
  • Gas-powered pressure washers should not be used in enclosed spaces or areas without proper ventilation
Pressure washing exterior stairs to remove dirt and mildew buildup.

Step-by-Step Guide: Using A Pressure Washer

1. Prepare the area.
2. Remove things you don’t want pressure washed.
3. Properly set up the pressure washer.
4. Connect the pressure washer to a water source.
5. Attach the necessary nozzle and accessory.
6. Spray at the surface keeping at least 3 feet away and not holding longer than 3 seconds on one spot.
7. Apply a cleaning solution if needed.
8. Do multiple passes on stubborn spots.
9. Let the surfaces dry and inspect.
10. Disassemble and store your pressure washer in an appropriate place.

Professional Pressure Washing Services

If you’ve decided that the project is way beyond DIY pressure washing, you can hire an expert instead. Pressure washing is a high-demand service in property maintenance.

CA Wash Pros is a top-rated pressure washing company serving residential and commercial properties throughout San Jose, CA and South Bay Area cities. We specialize in both pressure washing and soft washing solutions for your exterior surfaces.

Pressure Washing and Exterior Cleaning Prices

Here’s a quick list of our professional services and costs. Click on the links to learn more.

NOTES:

  • Prices are general estimates and do not determine your final quote for service.
  • Estimates depend on the size and scope of project
  • Additional cleaning solutions and minor repairs may incur additional costs

Start Pressure Washing Today

We hope you learned something from this definitive guide. It’s time to start that pressure washing project you’ve been planning to do. We wish you good luck!

Just remember, we are always here to help. For inquiries, call us today at 408-800-3692 or fill up our quote form to get in touch with a trusted professional.

FAQs: Pressure Washing

Does pressure washing increase the water bill?

Yes, pressure washing will cause a slight increase in your average cost of water bill. The increase depends on what you’re getting pressure washed and the size of the area getting pressure washed.

We do not have a fixed rate for the increase. We cannot determine it based on what we will pressure wash as well. But yes, there will be a slight increase.

It’s ideal to pressure wash exterior surfaces at least once or twice a year. Properties surrounded by trees, exposed to heavy rainfall, prone to mold and algae buildup, and high-traffic areas may require more frequent cleanings

Wait at least one day after pressure washing before you proceed with staining, sealing, or repainting. If you’re using a water-based sealer, you can proceed with sealing right away. Overall, it’s really a case-by-case basis.

Pressure washing uses high water pressure (2,500 to 3,500 psi) often without chemicals. Soft washing uses gentle water pressure (60 to 120 psi depending on the water spigot) and a biocide treatment.

Yes, our estimates are free of charge. Call us today at 408-800-3692 to get your FREE online quote!