When it comes to painting the perfect room, there are a lot of details to consider. One important question is whether to sand the walls before or after applying primer.
Both methods have advantages and disadvantages, so it’s important to weigh your options before deciding which approach is best for your project.
If you want a wall with a smooth surface that is free of bumps and imperfections, sanding the walls before the primer is the way to go. Or, if you need a fast process or need a more consistent paint color on your wall, then sanding the walls after the primer is the choice.
Why Should You Sand The Walls Before Applying Primer?
There are a few reasons why you should sand the walls before applying primer, which include:
Less Likely To See Imperfections
This method helps to create an even surface and gives the paint something to grip onto. If you don’t sand the walls before applying primer, you’re more likely to see imperfections in the finished product.
Even if the walls look smooth, there may be bumps or unevenness that will show up once the paint is applied. By taking the time to sand the walls beforehand, you can avoid these issues and create a professional-looking finish.

Allows For A Deeper Clean
When you sand the walls before applying primer, you also allow yourself to clean them more thoroughly.
This is especially important if the walls are already painted. Pre-existing paint can often contain dirt and debris that can prevent the new paint from adhering properly. By sanding the walls first,
Smoother Finish
Sanding also helps to create a smooth surface for the primer to be applied to. If your walls are bumpy or textured, sanding them down will give the primer a flat surface to adhere to, leading to a smoother and more even finish once applied.
In addition, sanding can help to fill in any small cracks or holes in the wall, further smoothing out the surface and creating a barrier against potential moisture damage.
How to Sand The Walls Before Applying Primer
Now that we’ve gone over some of the benefits of sanding the walls before applying primer, let’s look at how to actually do it.
First, gather your supplies. You’ll need a sheet of sandpaper, a bucket of soapy water, and a sponge. If you’re working in a large room, you may also want to invest in a power sander.
The first step is to choose the right type of sandpaper.

Most Surfaces
You will want to use medium-grit sandpaper. This will be abrasive enough to remove any dirt or debris from the wall’s surface without damaging the paint underneath.
Rough Surfaces
If you’re working with a particularly rough surface, you may need to start with coarse-grit sandpaper and then move on to a medium-grit once the majority of the imperfections have been smoothed out.
Once you’ve selected which sandpaper to use, wet the sponge and wring it out. Then, sandpaper in hand, start at the top of the wall and work your way down. As you sand, wipe away the dust with the sponge. Focus on one small area at a time so that you don’t miss any spots
In addition, it’s essential to keep the sandpaper moving to avoid creating any deep scratches.
Once you’ve gone over the entire wall, rinse the sponge and repeat the process with fresh water. This will remove any residue left behind by the sandpaper.
Finally, let the walls dry completely before applying the primer.
Why Should You Sand The Walls After Applying Primer?
There are a few reasons why you might want to apply primer before sanding the walls, and some are:
Time-Saving
First, it can save you time and effort. You won’t need to sand as much of the surface area by applying primer before sanding. This can be a big time-saver if you’re working on a large project.
Ease Of Application
Applying primer before sanding can also make the process easier. Sanding can be laborious, especially if you’re working on a large project.
By applying primer first, you can sand less of the surface area and focus on the areas that need it most. This can save you time and effort in the long run.
More Consistent Paint Color
You can achieve a more consistent paint color by sanding the walls after applying the primer. By covering the entire surface with primer, you’ll be able to reduce the amount of paint that’s needed to achieve the desired color. This can save you money in the long run.
Protecting The Wall From Scratches
Finally, applying primer before sanding can also help protect the wall’s surface from scratches. By creating a barrier between the paint and the wall, you’ll be able to reduce the amount of wear and tear on the surface. This can extend the life of your paint job.
How To Sand Walls After Applying Primer
Applying primer is an essential step in painting, but it can be tricky to get the perfect finish. If you’re not careful, you can end up with bubbles or streaks in the primer that will show through the paint.
To avoid this, sand your walls after you apply primer. This will smooth out any imperfections and create a more even surface for painting.
Start by using coarse-grit sandpaper to remove any significant flaws in the primer. You’ll want to make sure that you’re using circular motions and not going back and forth, as this can damage the wall.
Start with a small area and work your way up to cover all of the primer. Then, switch to finer-grit sandpaper and gently sand the entire surface.
Vacuum up the dust afterward so that it doesn’t spoil your paint job. With a little bit of effort, you can ensure that your walls are primed and ready for a professional-looking paint job.

Final Thoughts
Now that you know when sand your walls, you can make the best decision for your project. If you’re short on time, sand the walls after applying primer.
If you’re looking for a smoother and cleaner finish, sand your walls before applying primer. Whichever method you choose, make sure to use the proper sandpaper and take your time. With a little bit of effort, you can achieve perfect results.