Sanding Drywall Joints: Smooth Walls Ready for Paint

Drywall finishing is all about seamless walls and ceilings. Even with perfect taping and mudding, sanding is the step that makes joints invisible under paint. Done right, it leaves a smooth surface; done wrong, it creates dust clouds, grooves, or visible seams. This guide walks you through sanding drywall joints like a pro.

Why Sanding Drywall Joints Matters

Joint compound shrinks and leaves ridges as it dries. Sanding levels these ridges, smooths tape edges, and blends repaired areas into the surrounding wall. Skipping this step results in flashing lines and uneven paint.

Tools You’ll Need

• Drywall sanding sheets (120–220 grit)
• Pole sander or sanding block
• Shop vacuum with dust attachment
• Respirator and safety glasses
• Work light to check seams

Recommended Grit Sequence

• 120 grit: First pass to knock down ridges and high spots.
• 150 grit: Smooth transitions between compound and drywall.
• 220 grit: Final finish before priming and painting.

Step-by-Step: Sanding Drywall Joints

1. Check seams under light. Hold a work light at an angle to reveal imperfections.
2. Start with 120 grit. Use 120 grit (25-pack) sheets to level ridges.
3. Smooth with 150 grit. Switch to 150 grit (50-pack) for feathering edges.
4. Refine with 220 grit. Use 220 grit (100-pack) for a flawless surface ready for paint.
5. Vacuum dust. Use a shop vac attachment or wipe with a damp sponge.
6. Inspect and touch up. Reapply joint compound where needed, then re-sand lightly.

Special Cases

For ceilings, use a pole sander to reduce strain. In tight corners, fold sandpaper into thirds for control. For dust-sensitive environments, use a damp sponge to lightly smooth compound instead of dry sanding.

Pro Tips

• Work in circular motions for consistent blending.
• Don’t oversand—removing too much can expose drywall paper.
• Always prime before painting to lock in dust and prevent flashing.

Aftercare

• Use a primer-sealer before paint for uniform coverage.
• Inspect under different lighting angles before painting.
• Patch dents or scratches with a thin skim coat, then re-sand.

FAQs

• Do I need to sand between coats of compound? Yes, lightly sand after each coat for smooth buildup.
• Can I use power sanders? Yes, but control is key—hand sanding avoids oversanding seams.
• What grit is best before paint? Always finish with 220 grit for a professional result.

Watch & Learn

Sanding drywall joints is the secret to walls that look perfectly smooth. Stock up on drywall sanding sheets—available in packs of 25, 50, and 100. Shop drywall sanding sheets here.