How to Sand Drywall for Smooth Walls Before Painting (120, 180, 220, 320 Grit Guide)

Freshly installed drywall or patched repairs need proper sanding before painting. If you skip this step, paint will highlight every seam, ridge, or uneven spot. With the right grit progression, you can achieve a perfectly smooth surface that looks seamless once painted. This guide explains how to sand drywall without over-sanding or creating dust clouds.

Why Sanding Drywall Matters

Joint compound (mud) used on drywall seams dries rough and uneven. Sanding levels it to match the board surface and prepares it for primer and paint. Proper sanding also reduces the risk of visible tape lines or glossy patches after painting.

Tools & Supplies Needed

• Drywall sanding pole or hand sander
• Vacuum with HEPA filter or dust extraction system
• Respirator or dust mask
• Tack cloth or microfiber cloth
• Drop cloth to protect floors

Best Grit Sequence for Drywall

• 120 grit: Knock down ridges and high spots in joint compound.
• 180 grit: Smooth out broader areas for uniform texture.
• 220 grit: Refine surface and prepare for primer.
• 320 grit: Final sanding for a silky finish before painting.

Step-by-Step: Sanding Drywall

1. Inspect the wall. Use a bright work light to identify ridges and uneven seams.
2. Start coarse. Sand with 120 grit (25-pack) to flatten obvious imperfections.
3. Smooth seams. Move to 180 grit (50-pack) for a more consistent surface across joints.
4. Refine the finish. Use 220 grit (100-pack) to prep for primer application.
5. Final polish. Finish with 320 grit (25-pack) for a professional-grade smoothness.
6. Clean the surface. Vacuum dust and wipe with a tack cloth before priming.

Special Cases

• Ceilings: Use a sanding pole to reduce strain and reach evenly.
• Heavy buildup: Scrape excess mud before sanding to save time.
• Spot repairs: Feather edges with 220 grit to blend patches into surrounding drywall.

Pro Tips

• Work under angled light to catch imperfections you might miss head-on.
• Do not oversand—removing too much mud exposes tape and requires rework.
• Always sand in wide, overlapping strokes for consistency.
• Keep rooms ventilated but avoid fans that blow dust everywhere.

Aftercare

• Prime walls as soon as possible after sanding to lock down surface dust.
• Touch up small imperfections with spot sanding before painting.
• Use high-quality paint rollers for best wall coverage.

FAQs

• Can I use a power sander? Yes, but be cautious—power sanders can oversand quickly.
• Do I need to wet sand drywall? Wet sanding reduces dust but is slower; ideal for small repairs.
• What grit is best before primer? 220 grit is the sweet spot for primer adhesion.

Watch & Learn

Sanding drywall properly makes painting faster and flawless. Stock up on 120 to 320 grit sandpaper sheets in different pack sizes to prepare walls like a pro. Explore the full fine sandpaper collection for wall finishing projects.