Drywall Repair: Sanding Blistered Tape Without Damage

Blistered drywall tape creates raised bubbles that ruin the smoothness of walls. While it’s tempting to sand them aggressively, that often enlarges the damage. The key is combining careful cutting, filling, and controlled sanding to restore a flat, paint-ready surface.

Why Blistered Tape Needs Careful Sanding

When tape lifts, it leaves a hollow that sanding alone can’t fix. Over-sanding can shred surrounding paper and create a bigger repair. Correct sanding after cutting and filling makes the patch invisible once painted.

Tools You’ll Need

• Utility knife for cutting blisters
• Joint compound and taping knife
• Drywall sanding sponge or pole sander
• Vacuum or brush for dust
• Tack cloth

Recommended Grit Sequence

• 120 grit: For initial feathering around the cut area.
• 150 grit: For blending joint compound smoothly.
• 220 grit: For final sanding before priming.

Step-by-Step Process

1. Cut the blister. Slice through raised tape with a utility knife and peel away loose sections.
2. Feather edges. Sand surrounding drywall lightly with 120 grit (25-pack) to create a smooth transition.
3. Fill the void. Apply joint compound, pressing firmly to bond with the wall surface.
4. Smooth compound. Once dry, sand with 150 grit (50-pack) to blend the patch.
5. Final sanding. Refine with 220 grit (100-pack) for a paint-ready finish.
6. Clean carefully. Vacuum and tack cloth dust to prevent finish issues.
7. Prime & paint. Apply primer before paint for seamless blending.

Special Cases

If blistering is widespread, re-taping may be necessary. For small bubbles, cutting and spot filling is usually enough. Avoid sanding directly over hollow blisters—it only makes them worse.

Pro Tips

• Use light pressure when sanding drywall—too much force tears paper.
• Feather joint compound at least 6–8 inches around the repair for invisibility.
• Shine a work light at an angle to spot imperfections before painting.
• Always prime repaired areas to seal compound before paint.

Aftercare

• Inspect walls after paint cures—touch up with 220 grit if needed.
• Avoid excess moisture in the room, which can weaken tape adhesion.
• Keep extra sandpaper handy for quick touch-ups before repainting.

FAQs

• Can I just sand a blister flat? No—cutting and filling is required for long-term repair.
• What grit is best for drywall sanding? 120–220 grit is standard—never use coarse grits that damage paper.
• Do I need to re-tape large blisters? Yes, full re-taping ensures structural integrity.

Watch & Learn

By combining careful cutting, filling, and sanding, blistered drywall tape repairs can disappear completely—leaving smooth, paint-ready walls.