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A Guide for Pressure Washing Your House before Painting

May 27, 2019

Painting is one of the sure ways to give an entire new look to your property. For new exterior painting, you need to clean your siding properly. This can be a very hectic job if you are going to scrub your siding with hand. To get this work done soon with convenience, you can go for pressure washing. But remember it is tricky to use the pressure washer on a siding. If you are not paying the attention, the high water pressure will damage your siding. In worse situations, the water can damage the sheathing and wall cavities present below the siding.

To get your house painted well after cleaning your siding properly, you should contact professional house painters Cape Cod of The Barnstable Painters. We are having years of experience. We also use the right techniques and equipment to paint the house.

You might be wondering, how to pressure wash a house before painting? To answer your question, in this blog, we will share detailed information that you should know regarding the pressure washing before painting:

Cleaning is Must

There are many advantages of keeping your siding clean. The clean siding means your exterior paint lasting longer. When you are going to paint the dirty siding, this will reduce your paint lifespan. You know that paint is very expensive so it should be done right. It is better to clean your siding before painting instead of changing the paint after 3 to 4 years due to the dirty siding. Cleaning outside of the house with a pressure washer will make it clean and ready for painting.

Hand Washing or Pressure Washing

Well, both methods are good and the selection is dependent on your own convenience.

In hand washing, you need to have the time and energy to clean your siding with soap and water. This is a very difficult job to do because you have to clean your entire house with hands.

In the case of pressure washing, you don’t have to do any effort. You can get the best results with this method and it is easy as well.

Problems with Pressure Washing  


Do you have to wash a house before painting? The answer is yes! You need this so that your paint can last for longer time period. When we are talking about the pressure washing, the point here is to clean the siding before painting instead of striping the paint. You should remember that some pressure washers are very powerful and they can easily remove the paint. If you are planning to strip the paint, then it should be done using the scraper, heat gun, and sander after washing process.

The two main problems with pressure washing are listed below:

Etching: In some conditions, the pressure washer will damage concrete and brick. Keeping this in view, you can estimate the damage caused to the vinyl, cedar, or fiber-cement siding.

To avoid the problem, you should stand back at a certain distance when going to use the sprayer for siding. According to your PSI rating, an estimated distance can be 18 inches to 6 inches. Furthermore, you can use a fan-spray nozzle instead of a spray nozzle.

Injecting: You need to be careful when spraying at low angles under the siding. The high pressure can move water upward between the siding boards and will make the sheathing or insulation of water interior soggy. To avoid this situation, you should not spray at an upward angle to the siding. You should spray only perpendicular or slightly downward to eliminate the problem. You should also keep an eye on exhaust vents, air vents in crawl space or attic, and cracks around doors or windows.

Pressure Washers Types


A pressure washer is available in both gas and electric-powered models. As siding needs to be treated gently so an electric-powered power washer will be sufficient. The washer having PSI of 100 to 1500 is enough for washing the siding. If you have a two-story house, then you need to have a high-volume gas pressure fitted with a special nozzle to clean the upper area standing on the ground.

Equipment You Need

You need the following equipment:

  • Ladder (if needed).
  • Pressure nozzles and sprayer.
  • Best exterior house cleaning solution.
  • Sponge, bucket, and bleach for treatment of mildew.

Remember one thing that you should use cleaning solution especially made for siding. You should not buy a solution that is having bleach as this will damage the plants and spray washer.

Instruction for Pressure Washing

You need to keep the following instructions in your mind during the pressure washing process:

1-If there are any foundation shrubs or plants that are blocking the siding, then you should protect them with sheets of plastic to prevent stripping leaves of the plant due to pressure sprayer. Moreover, you should cover air conditioner compressors and other electrical utilities with the help of a plastic sheet before pressure washing.

2-You need to use the pressure spraying for removing the debris. Use the plain water to clean the surface from the top down. To get the best result, wide spray angle and low pressure will work best. The main goal here is to remove all the visible debris, insect nest, eaves, and dirt. After this, let the siding dry.

3- If your siding is having areas covered with mildew, then you need to make a bleach solution. Prepare the solution, by mixing 1 part of bleach with 10 part of water and apply the solution with the help of a sponge to the affected area. You can use a garden sprayer too for applying the bleach solution. Make sure that you don’t spill the bleach solution on a plant or other landscape plants.

4– Fill your washer’s tank with cleaning solution and spray the siding with water-solution mixture. The low and wide angle will work best. The pressure washer’s instruction will indicate the proper setting to apply the cleaning solution. When spraying, move upward with a consistent downward angle. You can use a ladder for pointing downward at the siding by moving up to one or two-step.

5-Allow the solution to work 10 minutes and then rinse using fresh water. In rinsing, more powerful setting along with wide spray pattern is used. You should rinse thoroughly for best cleaning.

If you are planning to the paint after couple of weeks, then spraying it down with fresh water will be best. Allow siding to dry properly for 48 hours before you start the painting.

Still wondering, how to paint your house exterior? You need to hire professional painters like The Barnstable Painters. But don’t forget to clean your siding before painting.

To know more about our services, you can call us at (508) 775-6106.


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