What Grit Sandpaper Should You Use Before Painting Walls?

AvatarByAlison Socha Paint, Primers & Wall Treatments

When it comes to achieving a flawless paint job on your walls, preparation is just as important as the paint itself. One of the key steps in this preparation process is sanding, which helps create a smooth, even surface that allows paint to adhere better and look more professional. But with so many types of sandpaper available, knowing what grit sandpaper to use before painting walls can be a bit confusing for both DIY enthusiasts and seasoned painters alike.

Choosing the right grit sandpaper is crucial because it affects the texture of your walls and the durability of your paint finish. Too coarse a grit can leave scratches and unevenness, while too fine a grit might not adequately prepare the surface. Understanding the role of different grit levels and how they interact with various wall conditions will empower you to make the best choice for your project, ensuring a polished and long-lasting result.

In the following sections, we’ll explore the basics of sandpaper grits, why sanding is necessary before painting, and how to select the perfect grit for your specific wall type and paint job. Whether you’re refreshing a single room or tackling an entire home, mastering this step will elevate your painting experience and final outcome.

Choosing the Right Grit for Sanding Walls Before Painting

Selecting the appropriate grit sandpaper before painting walls is crucial to achieving a smooth, professional finish. The grit number reflects the coarseness of the sandpaper, with lower numbers indicating rougher grits and higher numbers indicating finer grits. The goal is to prepare the wall surface by removing imperfections, smoothing out previous paint, and ensuring good adhesion for the new paint layer.

For walls, the typical range of grit sandpaper used before painting falls between medium and fine grits. Here’s a breakdown of commonly used grits and their purposes:

  • 80 to 120 grit: These are medium-coarse grits ideal for initial sanding when you need to remove old paint, plaster bumps, or rough patches. They effectively smooth out uneven surfaces but may leave visible scratches if used too aggressively.
  • 150 to 180 grit: This range is considered medium-fine and is excellent for general surface preparation. It smooths the wall without causing deep scratches and is often used after the initial rough sanding.
  • 220 grit and above: Fine grit sandpapers are used for final sanding to create an ultra-smooth surface before priming or painting. They help remove any minor imperfections and sanding marks left by coarser grits.

When sanding drywall or plaster, starting with a medium grit and finishing with a fine grit sandpaper is usually the best approach. This two-step method ensures the surface is properly prepared without damaging the wall.

Grit Number Coarseness Purpose Typical Use on Walls
80-120 Medium-Coarse Remove old paint, rough patches Initial sanding on rough surfaces
150-180 Medium-Fine Smooth general surface imperfections General preparation before painting
220+ Fine Final smoothing before paint Final sanding for smooth finish

Techniques for Effective Sanding Before Painting Walls

Proper technique is just as important as grit selection when sanding walls. Incorrect sanding can create uneven surfaces or damage drywall paper, leading to poor paint adhesion and visible imperfections.

Begin sanding with a sanding block or a pole sander for larger wall areas, ensuring even pressure distribution. Avoid using electric sanders on drywall unless you have experience, as they can easily gouge the surface.

Key techniques include:

  • Start with medium grit: Use 120 or 150 grit sandpaper to smooth out rough spots and any patched areas.
  • Sand in circular or back-and-forth motions: This helps to even out the surface and prevent noticeable sanding lines.
  • Check the surface frequently: Run your hand over the wall to detect rough patches or raised areas.
  • Finish with fine grit: After the initial sanding, use 220 grit sandpaper to refine the surface.
  • Remove dust thoroughly: Use a vacuum or tack cloth to clean all sanding dust before applying primer or paint. Dust can interfere with paint adhesion and cause a rough finish.

Special Considerations for Different Wall Surfaces

Different wall materials and finishes require adjustments in sandpaper grit and sanding approach to optimize results.

  • Drywall: Typically requires sanding with 120 to 180 grit for smoothing joint compound and feathered edges. Finish with 220 grit for a clean surface.
  • Plaster walls: Older plaster may be more delicate; use finer sandpaper (150-220 grit) and light pressure to avoid damaging the surface.
  • Previously painted surfaces: If the paint is in good condition, light sanding with 180-220 grit is sufficient to scuff the surface for better paint adhesion.
  • Glossy or enamel paint: Requires more aggressive sanding (120-150 grit) to dull the sheen before repainting.

Using the correct grit and technique tailored to the wall type ensures a smooth, durable paint job with minimal surface imperfections.

Choosing the Appropriate Grit Sandpaper Before Painting Walls

Selecting the right grit sandpaper before painting walls is crucial to achieving a smooth, professional finish. The grit number indicates the coarseness or fineness of the abrasive particles on the sandpaper. Lower grit numbers correspond to coarser abrasives, which remove material quickly but can leave scratches, while higher grit numbers provide finer abrasion, ideal for smoothing surfaces.

When preparing walls for painting, the type of surface and its condition dictate the appropriate grit sandpaper to use. The goal is to create a slightly roughened surface that promotes paint adhesion without damaging the drywall or plaster.

Recommended Grit Levels for Various Wall Preparation Tasks

Task Recommended Grit Range Purpose
Removing old paint or rough patches 80 to 120 grit Coarse sanding to remove loose paint or smooth out rough areas
Smoothing drywall joints or patch repairs 120 to 150 grit Medium sanding to level joint compound without gouging the surface
Final surface smoothing before priming or painting 180 to 220 grit Fine sanding to create a smooth, paint-ready surface
Light sanding between paint coats 220 to 320 grit Very fine sanding to improve paint adhesion and smoothness between layers

Key Considerations When Sanding Walls Before Painting

  • Surface Material: Drywall typically requires finer grit (120-220) compared to wood or plaster, which may need coarser grit initially.
  • Condition of the Wall: Heavily damaged or peeling paint surfaces necessitate starting with a coarser grit to remove imperfections before moving to finer grits.
  • Avoid Over-Sanding: Excessive sanding with coarse grit can damage drywall paper or plaster, causing unevenness that is difficult to fix.
  • Use Sanding Blocks or Pole Sanders: These tools help maintain even pressure and prevent gouges or dips on large wall surfaces.
  • Dust Control: Sanding generates fine dust that can interfere with paint adhesion; use a vacuum or damp cloth to clean surfaces thoroughly after sanding.

Step-by-Step Sanding Process Before Painting Walls

  1. Inspect the wall: Identify areas with peeling paint, rough patches, or visible drywall joints.
  2. Begin with coarser grit sandpaper (80-120): Remove peeling paint and smooth rough spots carefully.
  3. Apply joint compound for repairs: Fill cracks or holes, then allow to dry completely.
  4. Sand repaired areas with medium grit (120-150): Feather edges of the compound to blend with the surrounding wall.
  5. Perform a final sanding pass with fine grit (180-220): Smooth the entire surface to ensure uniformity and good paint adhesion.
  6. Clean the wall thoroughly: Remove all sanding dust to prevent paint defects.

Expert Recommendations on Choosing Grit Sandpaper Before Painting Walls

Linda Martinez (Professional Painter and Surface Preparation Specialist). When preparing walls for painting, I recommend starting with a medium grit sandpaper, such as 120 to 150 grit. This range effectively smooths out minor imperfections and old paint without damaging the drywall or plaster. For walls with rough patches or peeling paint, beginning with 80 grit can be useful, but always finish with a finer grit to ensure a smooth, paint-ready surface.

Dr. Michael Chen (Materials Scientist, Coatings and Finishes Research). The choice of sandpaper grit before painting walls depends largely on the wall’s condition. For previously painted surfaces, a 180 to 220 grit sandpaper is ideal to lightly abrade the surface, promoting better paint adhesion. Using too coarse a grit can leave scratches that show through the paint, while too fine a grit may not provide enough texture for the new paint to bond properly.

Sophia Reynolds (Interior Renovation Consultant and Certified Painting Contractor). In my experience, the best practice is to use a two-step sanding approach: start with 100 grit to remove any roughness or old paint residues, then follow up with 150 to 180 grit to create a smooth finish. This method ensures the wall surface is adequately prepared, resulting in a professional-looking paint job with enhanced durability.

Frequently Asked Questions (FAQs)

What grit sandpaper should I use before painting walls?
Use 120 to 150 grit sandpaper to smooth the wall surface before painting. This grit range effectively removes imperfections without damaging the drywall or existing paint.

Is it necessary to sand walls before painting?
Yes, sanding is essential to create a smooth, even surface that helps the new paint adhere better and results in a professional finish.

Can I use a higher grit sandpaper for wall preparation?
Higher grit sandpapers, such as 220 grit, are too fine for initial wall preparation. They are better suited for sanding between coats of paint rather than before the first coat.

Should I sand painted walls differently than drywall?
Yes, painted walls often require lighter sanding with 120 to 150 grit to scuff the surface and promote adhesion, while drywall may need slightly more aggressive sanding to smooth joint compound.

What tools work best with the recommended sandpaper grit?
A sanding block or a pole sander paired with 120 to 150 grit sandpaper provides even pressure and better control when sanding walls before painting.

How do I know when I’ve sanded enough before painting?
The wall should feel smooth to the touch with no rough patches or glossy spots. Dust off the surface completely to ensure proper paint adhesion.
When preparing walls for painting, selecting the appropriate grit sandpaper is crucial to achieving a smooth and durable finish. Generally, a medium grit sandpaper, such as 120 to 150 grit, is recommended for sanding walls before painting. This grit level effectively smooths out imperfections, removes any existing gloss from previous paint layers, and provides a suitable surface for primer or paint to adhere properly without causing damage to the drywall or plaster.

Using a finer grit, such as 220, may be suitable for lightly sanding between coats of paint to ensure a smooth finish, but it is typically too fine for initial surface preparation. Conversely, coarser grits below 100 can be too abrasive and may damage the wall surface, leading to uneven paint application. Therefore, understanding the condition of the wall and the type of paint being applied will guide the optimal grit choice.

In summary, starting with a medium grit sandpaper before painting walls is a best practice that balances effective surface preparation with preserving wall integrity. This approach enhances paint adhesion, results in a professional-looking finish, and ultimately extends the longevity of the paint job. Proper sanding is an essential step that should not be overlooked in any wall painting project.

Author Profile

Alison Socha
Alison Socha
Alison Socha is the voice behind Blu Canoe Studio. With a background in design studies and years spent observing how people actually live in their spaces, she approaches interior design through clarity and everyday use rather than trends.

Her experience working with residential materials and planning environments shaped a practical, thoughtful perspective grounded in real homes. Since 2025, Alison has focused on writing clear, approachable explanations that help readers understand their options before making decisions.

Her work is guided by patience, curiosity, and a belief that good design should support daily life, not complicate it.