Skip to Content

Pressure Wash: How to Strip Paint from Wood, Concrete, Metal

Planning on painting your house? Well, it’s common practice to strip off the old paint before priming and painting the new coat on. This can be a very labor intensive task. You can speed things up with a pressure washer.

Pressure washers can quickly strip off old paint and clean the underlying surface as you prepare for the new paint job. To strip paint off using a pressure washer you need to spray with a yellow nozzle. Stand about a foot or two away from the surface and spray with a sweeping motion. Work in manageable sections while never letting the nozzle spray in one location for too long. Most of the paint chips will fall off after several passes. You might need to scrape or sand any stubborn spots.

Seems easy, right? It definitely beats scraping and sanding by hand. While the task is indeed pretty straightforward, there are some minor details that you should be aware of before you start the job. Things regarding how to properly select and use the equipment and safety. Continue reading on to get the full picture of the process.

Basic Steps

  • Clear the area where you’ll be pressure washing. Be careful not to trip over anything.
  • Set up pressure washer. This includes connecting the unit to a water source and supplying the unit power. If you’re using an electric washer, plug it into a GFCI outlet and if you’re using a gas washer make sure there’s gas in the tank.
  • Connect the yellow nozzle to the pressure washer wand.
  • Turn the water on. Turn the power on.
  • Start with a standing position 2 feet away from the surface you’ll be cleaning.
  • Hold the spray wand with two hands. Aim while holding the wand at a 45 degree angle to the surface.
  • Pull the trigger and spray.
  • Use a sweeping motion while working in sections, and never allow an area to completely dry out. If spraying on wood surface work along with the grain.
  • Adjust standing position as needed. Move closer for more water pressure and further for less.
  • Use multiple passes to wash off stubborn stains.

Choosing the Right Equipment.

Electric or gas

People usually group pressure washers into those that are electric or gas. Electric pressure washers are more popular, simply because they’re more affordable and practical. Most of what you have around the house that can be pressure washed can be done with an electrical washer. The caveat is that these washers require an outlet, preferably a GFCI one.

Gas pressure washers are powered by gas motors. This design gives them more power. Their pumps are able to generate more pressure and the streams of water that come out are discharged at a much higher velocity. More powerful blasts of water mean more ability to break apart and lift up stubborn stains.

For stripping paint, an electric pressure washer is sufficient. It’s the most cost-effective choice. You can use it for other things around the house like cleaning fences or even washing cars.

Nozzles

Most pressure washer purchases include a set of color-coded nozzles. Each nozzle has a unique design that allows it to be used for specific applications. For example, the black nozzle is generally used for dispensing soap or detergent. It’s design has it putting out a wide spray pattern with low pressurized water.

For stripping paint most people use the yellow nozzle. It’s actually called the paint stripper, though it can be used on other jobs such as removing tough stains from concrete. The yellow nozzle has a narrow 15 degree spray pattern. With such a focused water stream, paint chips are easily lifted up from surfaces when blasted with water. They just fall to the ground.

PSI

You see the term PSI (pounds-force per square inch) used in conjunction with describing how powerful a pressure washer is. The higher the number the more powerful the water spray is. Of course, the nozzle has a part in it too. So while it may seem like power is a good thing, in certain instances it isn’t. 

I noted earlier that gas washers are able to reach higher PSI levels. A PSI of 3,000 or higher is typical on these types of machines. Electric washers usually pump out between 1,000 and 3,000 PSI, which is sufficient for most common pressure washing tasks.

If you’re pressure washing a wood house siding, a good starting point to consider is somewhere around 2,500 PSI with a yellow nozzle. Note, this setting is for stripping paint. If you’re just cleaning wood, choose a lower setting. Wood is a little bit more fragile in its composition and can chip if too much force is applied to it. Compared to a concrete surface, which is a lot more dense, wood is relatively soft.

It’s basically all trial and error. Once you start with a safe choice and setting, conduct a test spray to see the results. Adjust your spray distance or nozzle selection. You adapt to what’s suitable to your situation.

Safety

People often take their safety for granted. Usually it’s done for the sake of convenience. However, a pressure washer can be a very dangerous tool. Getting hit with pressurized water can cause serious injury or damage.

At the very least, consider wearing safety goggles. Protect your eyes. You don’t want to go blind when water droplets traveling at high velocities hit your eyes. There’s always that risk.

Other than that, gloves and boots are good at protecting other areas of your body.

In most instances of paint stripping, you’ll probably be washing a house.

Utilizing the Right Technique

Pressure washers are often used to strip paint off wood surfaces, such as from the siding of a house before painting. However, they can be used to strip paint from other things as well. Whatever you’re pressure washing, the technique is basically the same.

Assessing the surface to be cleaned

You can use a pressure washer to strip paint off of many things. It’s not just wood. Do you have graffiti on a concrete floor or wall that needs to be cleaned? How about paint on a metal surface.

Depending on what you’re cleaning, you may have to vary your approach. Some surfaces are are dense than others. Concrete is certainly more dense than wood. With concrete you can be a little bit more lax in your choice of water pressure selection.

Sweep the sections to be cleaned

When using a pressure washer, you never want to aim and spray straight onto a surface. This action might cause damage. Instead, spray at a 45 degree angle so that the spray is less intense and so that the pressurized stream of water can also do its job of lifting the paint.

Sweep back and forth using even strokes. Never linger around an area for too long. Make multiple overlapping passes to make sure sections are thoroughly covered.

An important note to keep in mind when pressure washing wood surfaces is that you want to wash with the wood grains.

Understanding Perks of Using a Pressure Washer

There are many, many perks to using a pressure washer as opposed to other methods for stripping paint. Although the machines can be pricey if you don’t have one, you’ll quickly see why you want one.

Uses

There are countless uses for a pressure washer, from cleaning cars and homes to stripping paint off of floors, it will come in handy quite often.

If this is an investment that you are a bit weary on whether or not you should go forth with, let me tell you that it is worth it by far. What is great as well as the machines vary as well, so it shouldn’t be too hard to find one that works with your budget. 

Time-Saver

Another great benefit that these machines offer is that they are true time-savers on practically any project that you use them. They are especially a time-saver when it comes to a task such as stripping paint, which can be an absolutely grueling process if you are not being efficient with it. 

This is another perk in my eyes as to why you should be looking to invest in one of these machines, as if you are using them for commercial purposes, they are great on cutting down on time, even by half in some cases. 

They aren’t just time savers on stripping paint, either. They are great for reducing time on pretty much any project, as I mentioned earlier. 

Final Thoughts

Stripping paint is not an easy task. You might be painstakingly scraping paint chips off with a scraping tool. Chemical strippers take time to kick in. Pressure washers can do the job quickly and easily. It’s quite fun as well.