How to Use Pressure Washer to Remove Paint from Concrete

How to Use Pressure Washer to Remove Paint from Concrete

A pressure washer can effectively wash and clean any surface, thanks to its ability to generate high water pressure levels. It can blast away layers of dust, grease, and other forms of dirt from wood, metal, fabric, plastic, concrete, and other materials. However, the level of cleaning it does on a surface may depend on the maximum output of your pressure washer and the pressure washer brand and model you are using.

Can you use a pressure washer to remove paint from concrete? Yes, a pressure washer could strip paint off from a concrete surface. However, you would need one with high-pressure levels and flow rates to effectively get the job done. The final results may also depend on other factors, like the kind of paint used.

Not all pressure washers are created equal. There are a few things you need to consider and investigate when picking a pressure washer to wash off paint from concrete. What are these considerations, and what are the brands worth checking out? Moreover, what other factors would affect your cleaning?

How to Clean Paint Off a Concrete Surface With a Pressure Washer

How to Clean Paint Off a Concrete Surface With a Pressure Washer

Once you have your pressure washer, here’s how you go about cleaning your concrete surface and peeling the paint away:

1. Clean and prepare the concrete surface.

Clean the concrete surface thoroughly by wiping off dust, dirt, or debris with a cleaning cloth. If the area is big, use a broom to sweep off the dirt and wash away dust with water. 

You should also manually scratch or peel off loose paint with a scraper or a knife. This is important if the paint you want to get rid of is oil-based. Let the surface dry completely.

2. Prepare the surrounding area.

Prepare the area around the concrete surface you are working on. Remember that high-pressure washers can cut skin, damage wood, and strip paint off surfaces, so if you can, take plants, furniture, and other objects out of the vicinity. If you can’t, get a waterproof cover to protect nearby fixtures and other sensitive surfaces.

You should also close all nearby windows and doors as you will be applying chemical paint strippers. This is to ensure that potentially harmful fumes don’t enter your house.

3. Apply paint stripper to the concrete surface.

Apply a stripper on the concrete in order to soften the paint. Get a paint stripper that is suitable for the type of paint stain used on the concrete surface. If it is water-based paint, get a water-based paint stripper or a solution of methylated spirits. For oil-based paint, you can also get an oil-based paint stripper. However, if you are not sure whether the old layer of paint is oil- or water-based, going for an oil-based stripper is the best option. 

To apply the paint stripper, pour the solution directly on the surface. Make sure to wear gloves, a mask, goggles, and closed-toe shoes before you do this as the chemicals can be harmful to your health. Let the solution sit overnight or for six to eight hours.

4. Clean off the paint using the pressure washer.

Set your pressure washer at 3000 PSI and blast away the paint stripper residue and the layer of old paint with the appropriate nozzle. Make sure to spray pointing downwards and move it in a sweeping motion to blast away paint chips from the surface effectively.

Hold the washer’s wand with firmness, while also keeping a separation of 12 to 18 inches from the concrete surface. This angle and distance allow the force of the water to penetrate through the coats of paint without destroying the surface.

You may want to focus on more manageable portions if it is a large area of concrete.

5. Collect you wash water.

Once you have removed the paint, contain and collect your wash water and dispose of it appropriately.

Is it Okay to Wash Paint Off Without Using a Stripper?

Is it Okay to Wash Paint Off Without Using a Stripper?

If you prefer to skip the paint stripper and just blast the paint away from the concrete surface without the help of any chemicals, you can also do that. In fact, ditching the chemicals is advisable if you have small kids and pets at home.

What are the alternatives?

For one, you can also use sodium bicarbonate, which is more commonly known as baking soda, as an alternative to the paint stripper. You can fill your pressure washer’s reservoir with baking soda and then spray the area you wish to clean.  

You can also go for non-toxic paint strippers, which are available in the market. There’s Soy Gel, which is a biodegradable, low-odor, and non-toxic paint stripper that uses American-grown soybeans instead of methylene chloride to remove paint from surfaces.

Of course, you can also just use water with your pressure washer and skip any other softening solution altogether. But as to whether it will completely get rid of the paint depends on the condition of your concrete surface and the paint used.

Things to Remember When Pressure Washing

Things to Remember When Pressure Washing

Keep in mind that you don’t have to strip all of the old paint. So, when the surface has completely dried, you may have to chisel or lightly buff out any remaining specks of paint that were not removed. If you wish to repaint, you may need to wait for a handful of days before you can start.

Moreover, before you get started, you may want to talk to a professional about your home water supply. Find out if you are on well-water or low-pressure municipal water supply. This is because pressure washers rely on a sufficient inflow of water, and if you have low water pressure, your washer may be ineffective and could end up being damaged during use.

It is also important to read your pressure washer’s user guide or owner’s manual. This helps make sure that you will operate it properly and then store it the right way once you are done using it.

Additionally, when you are working with chemical paint strippers, make sure you are in a well-ventilated place. While there are several chemicals that were designed for the specific purpose of removing paint from concrete, their effectiveness is still determined by whether the paint has penetrated into the concrete. These strippers will work well if the paint hasn’t and is merely on the surface.  Also, make sure to follow the directions on the stripper’s container, especially as it pertains to how much you need to apply and how to apply it safely.

Why Use a Pressure Washer to Clean Off Paint?

Why Use a Pressure Washer to Clean Off Paint?

If your fence is made of concrete and you would want to update and give it a fresh coat of paint, you would need to prep the surface first. This means removing the old layer of paint to provide a solid base for the new one. Doing this would also help your new layer of paint adhere to the concrete better.

However, removing the current layer of paint would be time-consuming and ineffective without the aid of a pressure washer. Manual scrubbing and scraping, even if you use a metal brush, would also mean unwanted labor costs. This method is outdated and could end up being counterproductive. Not to mention that dry scrubbing would release paint dust and fine particles into the air, and these could get into your eyes and irritate them or get into your lungs when you breathe them in.

Using chemical strippers exclusively, on the other hand, may speed up the process, but it also increases the risk to your health and to the environment. Moreover, you would need to give it a six to eight hour set time, which is crucial for good results but could add to your labor costs and overall time expense.  

As such, using a pressure washer is practical and more effective at cleaning off the old layer of paint on your concrete surface. Aside from this, your pressure washer would also remove built-up grime, which would promote better adhesion for your new paint.

It’s Not the Same for Other Surfaces

Using a pressure washer to wash off paint may be a convenient and sensible choice if we are talking about concrete. However, that may not be the case for paint on other surfaces like wood, aluminum, sheet steel, fiberglass, old bricks, plastic, and other materials. Using high pressure may not only blast away the paint, but it may also damage the surface. Some materials could break, warp, or dent.  

For surfaces you think could break or get damaged, you may want to consult with a professional or hire one to do the job.

Paint and Concrete 

Paint and Concrete

Concrete is porous and therefore absorbs paint. So while you can clean paint off using a power washer, it might not be as quick and easy as you’d hope. 

Paint is easier to wash off if the concrete surface had been sealed or if a primer had been applied before it was painted on. Otherwise, you can expect the paint pigment to have penetrated deep beneath the surface and to have stained the concrete permanently. If this is the case, you may be able to peel the paint off, but there would likely be some color left behind.

Moreover, water-based and oil-based paints react differently to concrete. Water moves easily through porous materials so that water-based paint would seep into the concrete’s pores and cracks. 

What if it is Lead Paint?

You should be very careful about removing old paint as it might be lead-based, especially if the paint was applied before the late 1970s. Lead-based pigment is dangerous and harmful to your health. If you suspect this, you should consult a professional before you start to do the job of cleaning off the paint yourself.

What if it is Spray Paint?

Spray paint stains can be stubborn. You may be able to clean spray paint using a soapy solution, plus some elbow grease. However, chemicals are more likely to be the most effective at it. More specifically, you can use a mixture of water and trisodium phosphate, which is a chemical compound that is used to remove grease and stains from concrete. This is a common ingredient found in household cleaners.

You can apply a generous amount of trisodium phosphate to the spray-painted surface. Leave it for a few minutes to allow the chemical to set in and permeate the porous surface of the concrete. After that, you can use a pressure washer or a scrub brush to scratch the loose paint.

Choosing the Right Kind of Pressure Washer

A pressure washer can easily remove paint, especially if a sealant was used prior to applying the paint on the concrete surface. And the higher PSI the pressure washer has, the more effective it is going to be at blasting paint off. Pounds per square inch or PSI refers to the level of cleaning pressure your washer can produce. 

Which PSI is More Effective?

A high-pressure washer with 1,200 to 2,000 PSI can clean dirt and grime off surfaces in preparation for a new coat of paint, but it won’t be able to remove much of the old paint. A stronger washer, with a PSI of 2,500, works better in taking off peeling or flaking paint. However, a 3,000 PSI washer is the most effective at cleaning paint off the surface. 

So, as a rule, you will need a pressure washer that can generate 3,000 PSI and a flow of at least 2.5 GPM (gallons per minute) to clean dirty concrete effectively in order to wash off the old layer of paint. You can also find pressure washers that come with a maximum water pressure of 4000 PSI, and they can effectively strip off paint from a concrete surface. 

Gas vs. Electric Pressure Washer

Pressure washers are available in both gas-powered and electric models. Both can do the job well. But which one should you get to remove paint from concrete?

If you want something that is cheaper and requires less maintenance, an electric powered pressure washer would be the better choice. However, it may provide you with limited mobility. Because it relies on an electric plug, this pressure washer may not be able to reach areas that are very far away from an outlet.

Electric washers are also less powerful. It may not produce the amount of pressure you need to clean some hard surfaces. Generally, electric pressure washers create only 1300 to 1700 psi with a water flow of 1.5 GPM.

Gas-powered pressure washers, on the other hand, are more powerful and can clean faster. As such, they are more suitable for big cleaning jobs. In fact, a gas-powered pressure washer is perfect for cleaning paint off a concrete surface. It can be too strong for other cleaning applications, though.

How to Choose a Pressure Washer Nozzle

How to Choose a Pressure Washer Nozzle

There are a few types of pressure washer nozzle tips offering you a variety of spray angles and water pressures. The right kind of nozzle will help you remove paint from the surface. 

Nozzle tips for pressure washers are color-coded. These are:

Red, zero-degree nozzle

This tip has a high level of pressure and shoots a direct get of water on to your target surface. It hits an area as small as a quarter coin. 

This nozzle is not recommended for use on surfaces that are easily damaged. For instance, it certainly cannot be used for removing paint on wood. Many manufacturers also advise that you avoid the zero-degree nozzle as much as you can because it can be unsafe. It also comes with a warning to never, ever point it at anyone.

Yellow, 15-degree nozzle

This nozzle creates a 15-degree wide sheet of water spray that is ideal for medium stripping. When the spray of water hits the surface, the pressure is less because the force is spread over a larger area than a zero-degree nozzle. When used from the right distance, you can prepare surfaces for painting. It can also be great at removing tough dirt and mud.

Green, 25-degree nozzle

This tip creates an even bigger sheet or fan of water, thus putting less pressure on the surface. This gentle lifting and cleaning top is the most common nozzle tip to use around the house. It is also great for cleaning cars, boats, patio furniture, and even driveways.

White, 40-degree nozzle

This tip is for minimum spraying. It is considered to be the most gently spray of water and is, therefore, the perfect tip to use for cleaning fragile surfaces like blinds and windows. If you hold it at the right distance, you could effectively remove paint on large surfaces or clean your windows.

Gray or black, 65-degree nozzle

This is a soaping tip nozzle. It has the widest degree and a larger orifice, which helps decrease pressure while increasing pressure in the hose. This, in turn, pulls detergent into the line so that you can apply it to the surface.

Turbo or Rotary Nozzle

This is one of the most useful nozzles as it combines the force of the red nozzle with the spray area of a 25-degree top. It adds a pulsing action by rotating the water jet at 1800 to 3000 rpm. When the water hits the surface, it creates a round cone shape.

What Spray Nozzles and Other Accessories to Use?

Most of the spray tips or nozzles for pressure washers are great for washing off mold and dirt, but there are high-pressure nozzles that give a fine, strong spray for stripping paint. A 15-degree yellow tip and a 25-degree green tip nozzle are usually the best ones to use for blasting off paint from concrete.

Aside from these nozzles, the additional accessories you may need include rotary nozzles and a wet vacuum. You may also need a low-pressure nozzle for applying detergent and a wide-angle nozzle for rinsing.

You would also need a chemical paint stripper, a detergent, a broom, and a cleaning cloth. You should also prepare protective gear like rubber gloves, mask or respirator, and safety goggles.

Best Pressure Washers You Can Buy

Best Pressure Washers You Can Buy

If you are looking for the best pressure washer products for concrete, here are three recommendations:

1. WEN PW3100 Gas Pressure Washer

  • Water pressure: 3100 PSI
  • Flow rate: 2.5 GPM

The WEN PW3100 Gas Pressure Washer is a 3100 PSI unit that boasts a powerful 208cc 4-stroke OHV engine that pumps 2.5 gallons per minute. This product includes five quick-connect nozzles: zero-degree, 15-degree, 25-degree, 40-degree, and a soap nozzle.

The product has 12-inch wheels, allowing you to move the washer effortlessly throughout various tough terrains. It also has a 30-foot reinforced hose, a quick-connect spray gun, and an onboard soap tank. 

This gas-powered pressure washer is perfect for cleaning driveways and for blasting off dirt and grime from any surface. It comes with a two-year warranty.

2. Simpson Cleaning MSH3125 MegaShot Gas Pressure Washer

  • Water pressure: 3200 PSI
  • Flow rate: 2.5 GPM

The Simpson MegaShot Gas Pressure Washer is powered by a Honda GC 190 premium residential engine that pumps 2.5 GPM of water at 3200 psi through an ergonomic spray gun. It has 10-inch four-ply premium pneumatic wheels that offer your utmost mobility as well as increased stability and shock absorption.

What’s more, this product is very durable, with a heavy-duty steel frame tube and base plate. It comes with five quick-connect nozzle tips: zero-degree, 15-degree, 25-degree, 40-degree, and a soap nozzle. It also has a flexible 25-meter Morflex hose.

This easy-to-use gas-powered pressure washer is ideal for use on cleaning driveways, cars, house sidings, RV’s, decks, patios, and outdoor furniture. It is also great for prepping home exteriors for painting. It is a practical choice for homeowners because it is lightweight and easy to maneuver. 

It comes with a two-year limited warranty for its Honda consumer engine, a one-year limited warranty for its pump, a five-year limited warranty for its frame, and a 90-day warranty for its accessory.

3. TEANDE Gas Pressure Washer

  • Water pressure: 3600 PSI
  • Flow rate: 2.8 GPM

The TEANDE Gas Pressure Washer is equipped with a powerful 7HP 4-stroke OHV engine. It has a water pressure of up to 3600 PSI and a flow rate of up to 2.8 GPM, both ensuring a smooth high-pressure output, which is needed for heavy and long-time washing.

This product comes with five nozzles that are quick and easy to attach. You can use the zero-degree, 15-degree, 25-degree, 40-degree, and soap nozzles for various cleaning tasks, like cleaning porch, driveways, walkways, fences, tiles, terraces, garden, cars, trucks & boats, and pools. 

It has heavy-duty 10-inch premium pneumatic rubber wheels, which allow you to take it anywhere beyond your garage. Its 7.5-meter flexible hose allows you to maneuver it easily while you are cleaning, and even when you are storing it after use. This product also comes with a high-pressure gun, a metal extension lance, a detergent can, and a cleaning needle.

Is Pressure Washing Environmentally Friendly?

Is Pressure Washing Environmentally Friendly?

Using a pressure washer to clean surfaces, whether of dirt, dust, grime, grease, or paint, is actually environmentally friendly, especially if you decide to skip the use of chemical paint strippers. It helps keep pollution at bay.

When done correctly, pressure washing also helps keep pollution away from local waterways. It’s because clean surfaces mean less dust, dirt, and contaminants are washed off and released into the waterways or sewers. The important thing is to make sure the wastewater from pressure washing is collected and properly disposed of.

How to Safely Dispose of Water from Pressure Washing?

Different states and cities have listed down the acceptable practices for the disposal of wash water from pressure washing and other surface cleaning operations. 

Here is one example–Charlotte, North Carolina permits individuals to discharge wastewater into the storm drain, the sanitary sewer, landscaped area, and environmental waste company as long as the cleaning only involves dust and dirt and as long as soap or chemicals have not been used. However, if soap and chemicals were used, or if the cleaning involves oil and grease buildup, the discharge options will be limited.

In this example, when it comes to pressure washing building exteriors, fences, walls, and other structures to remove paint, whether or not soap or chemicals have been used, you are generally not allowed to discharge wastewater into the storm drain or into the sanitary sewer. You can, however, discharge it into landscaped areas or have an environmental waste company take care of it. This is to ensure that wastewater possibly containing hazardous lead or mercury-based paint is handled accordingly and does not make its way into the waterway.

Moreover, residents are requested to collect paint chips that are dislodged while pressure washing. They recommend that a canvas tarp or filter fabric be laid on the ground where the structure or object is being washed. This tarp or fabric will catch the wastewater and keep it from entering the street drainage.

Final Thoughts

Using a pressure washer is an excellent way to remove paint from concrete.  With the right machine and a little know-how and safety precautions, you can be well on your way to having concrete ready for whatever project you have in mind.

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