Sand Drywall Walls
Achieve a smooth, professional finish by properly sanding your drywall with 120-150 grit sandpaper. This critical step prepares walls for priming and painting.
Why Proper Sanding Matters
Sanding is the final step that transforms rough drywall into a smooth canvas ready for paint. Even perfectly applied joint compound will have ridges, bumps, and texture that must be removed. Paint and primer will actually highlight imperfections rather than hide them, so thorough sanding is essential for a professional-looking finish. While it creates dust and requires patience, proper sanding makes the difference between a basement that looks DIY and one that looks professionally finished.
Tools & Materials Needed
Step-by-Step Sanding Guide
Prepare the Area
Proper preparation minimizes cleanup and protects your health:
- •Seal off the work area with plastic sheeting and zipper doors
- •Close all HVAC vents and cover returns with plastic
- •Wear a quality respirator mask rated for fine dust (N95 or better)
- •Set up work lights at angles to create raking light that reveals imperfections
- •Have shop vacuum ready for periodic cleanup
First Pass with 120-Grit
Attach 120-grit sandpaper to your pole sander and begin removing high spots:
- •Use light to medium pressure - let the paper do the work
- •Work in circular or figure-8 motions to avoid creating grooves
- •Focus on high ridges along seams and screw dimples
- •Feather edges where compound meets bare drywall
- •Stop when surface feels relatively smooth to the touch
Warning: Never sand through the paper face of the drywall. If you see brown paper, stop immediately - you've gone too far and will need to apply more compound.
Check for Imperfections
After the first pass, thoroughly inspect your work:
- •Hold work light at a low angle to cast shadows on the wall
- •Look for bumps, ridges, divots, or uneven areas
- •Run your hand over the surface to feel imperfections
- •Mark problem areas with pencil for additional sanding
- •Large divots may need another coat of compound before final sanding
Second Pass with 150-Grit
Switch to 150-grit paper for the final smoothing:
- •Use lighter pressure than the first pass
- •Focus on creating a uniform, smooth finish across all surfaces
- •Blend all transitions between compound and drywall
- •Pay extra attention to corners and edges
- •Work until the surface feels glass-smooth to your hand
Final Inspection and Cleanup
Complete the sanding process with thorough inspection and cleanup:
- •Do a final inspection with raking light from multiple angles
- •Vacuum all surfaces - walls, ceiling, floor - to remove dust
- •Wipe walls with slightly damp microfiber cloth to pick up remaining dust
- •Allow walls to dry completely before priming
- •Clean or replace HVAC filters after removing dust barriers
Pro Tips
- ✓Invest in a vacuum sander attachment - it captures 90% of dust and saves hours of cleanup
- ✓Sand at night, then inspect with fresh eyes in morning light - you'll spot issues you missed
- ✓Replace sandpaper frequently - dull paper creates more work and damages surfaces
- ✓For tight corners, wrap sandpaper around a sanding sponge for better control
Frequently Asked Questions
What grit sandpaper should I use on drywall?▼
Start with 120-grit sandpaper to knock down high spots and ridges, then finish with 150-grit for a smooth surface. Never use anything coarser than 100-grit as it will damage the paper face of the drywall. For final touch-ups, 220-grit can be used sparingly.
How do I minimize drywall dust when sanding?▼
Use a vacuum sander that captures dust as you work, seal off the work area with plastic sheeting and zipper doors, close HVAC vents, run an air purifier, wear a respirator mask, and consider wet sanding techniques for final passes. Always clean up thoroughly as drywall dust spreads easily.
Should I sand between coats of joint compound?▼
Yes, lightly sand between coats with 120-grit paper to remove any ridges or bumps before applying the next coat. This ensures each layer bonds properly and creates a smoother final surface. The final sanding after the last coat should be more thorough.
How can I tell if my walls are smooth enough?▼
Use a bright work light held at an angle (raking light) to cast shadows that reveal imperfections. Run your hand over the surface to feel for bumps or ridges. The wall should feel smooth with no visible ridges, bumps, or divots. Remember that primer and paint will highlight imperfections, so be thorough.