Do You Sand Plaster Walls Before Painting: A Guide

March 13, 2023

Painting the walls of your home or business can be a daunting task. There are many questions that arise when it comes to preparing for painting, such as: do you sand plaster walls before painting?

The answer is yes. Sanding plaster walls prior to painting has several benefits and is an important step in ensuring quality results.

In this blog post, we will discuss why you should sand plaster walls before painting, what tools and materials are needed for the job, and how to go about prepping them properly. So if you're wondering "do I need to sand my plaster wall before applying paint?", then read on.

Table of Contents

Preparing Plaster Walls for Painting

Cleaning the Walls

Before painting plaster walls, it is important to clean them first. This will remove any dirt and debris that could interfere with paint adhesion.

A mild detergent mixed with warm water can be used to wipe down the walls, followed by a rinse of plain water. Allow the walls to dry completely before proceeding with primer or sanding.

Applying Primer

Applying primer helps create a uniform surface for painting and provides additional protection against moisture damage. Primers are available in both oil-based and latex varieties, so choose one that best suits your needs. Be sure to follow all manufacturer instructions when applying primer for optimal results.

Sanding is necessary in order to smooth out any uneven surfaces on plaster walls prior to painting. Start by using coarse grit sandpaper (60-80) to remove any imperfections in the wall surface such as bumps or ridges; then move on to medium grit paper (100-120) for smoothing out uneven areas; finish up with fine grit paper (150-180) for an evenly textured surface prior to painting application. It is also important not to forget protective gear like goggles, masks, and gloves when sanding plaster walls as this will help protect you from dust particles and other potential hazards associated with this task.

Preparing plaster walls for painting is essential to ensure a quality finish. Sanding the walls helps to create an even surface and improves paint adhesion, resulting in better coverage and longer-lasting results.

Benefits of Sanding Plaster Walls Before Painting

Sanding plaster walls before painting offer several benefits that can help to ensure a professional-looking end result. Smoothing out uneven surfaces is one of the most important advantages of sanding. By using coarse grit sandpaper, any imperfections in the wall surface can be removed, resulting in an even application of paint and preventing visible brush strokes or roller marks from appearing on the finished product.

Using medium grit paper to smooth out uneven areas further helps to create a uniform texture across the entire wall surface. This ensures that no areas are missed when applying paint and provides a more consistent look overall. Finally, fine-grit paper should be used for an evenly textured surface with minimal imperfections.

Enhancing paint adhesion is another benefit of sanding plaster walls before painting. Sanding creates tiny grooves in the wall’s surface which allow for better absorption of primer and paint, ensuring that it will last longer without chipping or peeling off over time. Additionally, this improved adhesion helps prevent moisture damage by providing an extra layer between the plaster and exterior elements such as rain or snow.

Tools and Materials Needed for Sanding Plaster Walls

Sandpaper or a sanding block is necessary for removing any imperfections in the wall surface prior to painting. Coarse grit sandpaper should be used first to remove any bumps or ridges, followed by medium grit paper to smooth out uneven areas and fine grit paper for an evenly textured surface. Sandpaper can be purchased at most hardware stores and comes in various sizes depending on the area being worked on.

A vacuum cleaner or dustpan and brush are also needed when sanding plaster walls as they help remove dust created during the process. Vacuuming up excess debris will prevent it from settling onto furniture, floors, carpets, etc., while brushing away any remaining particles ensures that no dirt gets left behind after sanding has been completed.

Protective gear such as goggles, a mask, and gloves should also be worn when sanding plaster walls in order to protect against inhaling dust particles or getting debris in your eyes or skin. Goggles provide full eye protection from flying pieces of plaster while masks filter out airborne particles so you don’t breathe them into your lungs. Gloves help keep hands clean while providing extra grip for better control over tools like sanders and blocks which can slip easily if not held securely enough due to their weight.

do you sand plaster walls before painting


Steps to Follow When Sanding Plaster Walls Before Painting

Prepare the Room and Protect Furniture and Floors from Dust and Debris: Before beginning your sanding project, make sure to protect furniture, floors, and other surfaces from dust created during sanding by covering them with drop cloths or plastic sheeting. Also, be sure to open windows for ventilation if possible.

Start with Coarse Grit Sandpaper to Remove Any Imperfections in the Wall Surface: Start by using coarse grit sandpaper (around 40-60 grit) on an electric sander or hand block sander to remove any imperfections such as bumps or ridges that may have formed over time due to wear and tear of wallpaper or previous coats of paint. Be sure not to press too hard while sanding so you don’t damage the wall surface further.

Move on to Medium Grit Paper To Smooth Out Uneven Areas: Once all imperfections have been removed, switch out your coarse grit paper for medium grit paper (around 80-100). This will help smooth out any uneven areas left behind after removing larger imperfections with coarse grit paper. Make sure you move slowly across each area being careful not to apply too much pressure which can cause damage instead of smoothing it out like intended.

Finish With Fine Grit Paper For An Evenly Textured Surface: Finally, use fine grain paper (150 - 180) along edges where two different textures meet such as corners between ceiling/wall junctions or window frames/walls junctions, etc., this helps create a seamless transition between textures giving your finished product a professional look once painted over.

Key Takeaway: Sanding plaster walls before painting is essential to achieving a smooth, even finish. To do this, use coarse grit sandpaper (40-60) to remove any imperfections in the wall surface, medium grit paper (80-100) for smoothing out uneven areas, and fine-grain paper (150 - 180) along edges for an evenly textured surface.

FAQs in Relation to Do You Sand Plaster Walls Before Painting

How do you prepare plaster walls for painting?

First, it is important to clean the wall surface with a damp cloth or sponge to remove any dust and dirt. Next, fill in any cracks or holes with spackling paste and sand them down until smooth.

Finally, apply an even coat of primer before beginning the actual painting process. This will help ensure that the paint adheres properly and provides a better finish when completed. With the right preparation, your plaster walls will be ready for a beautiful paint job.

How do you sand plaster walls for painting?

Sanding plaster walls is an important step in preparing them for painting. It helps to create a smooth surface and remove any imperfections or bumps. To sand plaster walls, start by using medium-grit sandpaper to lightly scuff the entire wall. Then switch to a finer grit paper and repeat the process until the wall is completely smooth.

Finally, use a vacuum cleaner with an attachment designed for drywall dust removal to ensure all particles are removed from the surface before painting begins. With proper preparation, your interior paint job will look professional and last longer.


In conclusion, sanding plaster walls before painting is a great way to ensure that your paint job will look its best. It helps to create a smooth surface for the paint and can also help reduce any imperfections in the wall. Sanding is an important step when it comes to preparing plaster walls for painting and should not be overlooked.

By following these steps and using the right tools, you can make sure that your do-it-yourself project turns out just as good as if it were done by a professional painter. So, if you're wondering "do you sand plaster walls before painting?" The answer is yes. 

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