Preparing Your Exterior Wall for Painting

Whether you are painting exterior walls for the first time or repainting, painting exterior walls is an excellent investment to bring out the best of a property.

Unfortunately, the most common mistake of painting exterior walls is the preparation process.

Preparing the walls for painting is the most crucial aspect of it, and how much work goes into preparing the walls for painting determines the result.

Hence, it is best to go through the right guide to prepare your walls for painting.

Scrap Exterior Walls
Do you want to know how to prepare this kind of wall before painting?

Here is exterior wall painting process step by step and all you need to know about painting them.

Can I Just Paint Over Old Paint?

Yes, you can paint over old paint. Painting over old exterior paint is even easier than painting new walls since old paint means the walls have been prepared during the previous painting, requiring less preparation.

However, if the walls are old, you might want to consider filling and sanding them before applying new paint. Here are a few tips to get you started.

Wash the walls

Washing is the first preparation step for painting new paint on an old one. This helps free the walls of grease and dust.

Fill the cracks

Cracks and holes in the walls absorb paints, requiring more paint than needed. Hence, invest in a flexible filler to fill gaps and holes in the walls.


While you might not need sanding for the walls since they have been painted before, sanding is necessary for the filled cracks and holes. Also, apply a primer to the filled areas to prevent a patchy look.

Apply a white matte emulsion

Applying a white matte emulsion is necessary to paint a lighter color than the old one. This process will help prevent the former color from showing through.

Do I Need To Scrap Exterior Walls Before Painting?

Scraping your exterior walls before painting is one important step you don’t want to skip out. By scraping, you remove loose paint to give a smooth surface for a new painting.

Remember, the smoothness of your painting job depends on the surface and not on the paint, such that smooth painting is impossible on an unprepared, unsmooth surface. Hence, take the time to scrape off the loose paint.

How To Paint Exterior Walls
Scraping before painting | Source:

A 5-way painter’s tool is the best tool for this task. Working your 5-way painter’s tool on the affected areas, remove the loose paint from the walls.

Also, note that some areas might not show signs of loose paint but have air in between. The best way to check air is to tap suspected areas and listen to the sound they give. An area with a hollow sound calls for scrapping, while a strong sound indicates skipping.

Do I Need To Sand Exterior Walls Before Painting?

Like scraping, sanding is another step on how to clean exterior walls before painting. Several reasons call for sanding the surface. For example, if there were cracks and holes in the walls you have filled, you want to sand the areas, as fillers are not as smooth to give smooth painting.

Sand Exterior Walls
Exterior wall sanding | Source:

While you don’t need to sand the whole surface, ensure you sand uniform areas to have a smooth, uniform surface after painting.

Do I Need To Wash Exterior Walls Before Painting?

Yes, it is best to wash your exterior walls before painting. Washing your walls helps remove dirt and dust from the surface.

Pressure washing exterior walls is considered the best practice. While pressure washing helps save time, it also enhances adequate cleaning of the surface.

Clean Exterior Walls Before Painting
It is essential to clean a wall before painting it | Source:

However, you can still use regular water through a garden hose to clean exterior walls, but note that it will take time and won’t be as adequate as using a pressure wash.

Do I Need To Prime Exterior Walls Before Painting?

Priming is a crucial preparation process for exterior wall painting, as it helps prepare the wall for better adhesion by sealing the surface. However, the question is, is it necessary to apply prime every time you paint?

The answer is, “it depends.”

Whether you need to prime your exterior walls before painting or not depends on a few factors, such as the condition of the wall, the paint type, and the colors of the new and old paint.

When not to prime exterior walls before painting

  • The wall is smooth and clean, and the colors of the old and new paint are the same
  • The former and new paint types are the same

When to prime your exterior walls

  • You are applying oil-based paint on latex paint (latex paints won’t hold oil paint)
  • The walls are damaged, and you need something to cover-up
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proPERLA® offers a range of exterior super hydrophobic waterproof paints & coatings designed to reduce energy costs and protect homes.

Through our official network of applicators, we provide services to end customers, ensuring the correct application of our products for your benefit.

Whether you are a professional interested in working with our products, or a customer looking for solutions, contact us for more information.

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