Sanding Wooden Floors Before Refinishing: Complete Grit Guide

Refinishing hardwood floors can transform a dull, scratched surface into a stunning centerpiece of your home. The key to success is sanding with the proper grit sequence. Rushing or skipping grits can leave swirl marks, uneven surfaces, or a finish that won’t last. Here’s a complete guide to sanding wood floors step by step.

Why Sanding Floors Matters

Floor sanding removes old finish, evens out scratches and dents, and opens the pores of the wood for stain or polyurethane. Without thorough sanding, the new finish won’t bond properly, leading to peeling, uneven color, and wasted effort.

Essential Tools

• Drum sander for main floor areas
• Edger sander for corners and walls
• Vacuum with brush attachment
• Tack cloth or microfiber rag
• Silicon carbide sandpaper sheets and belts

Recommended Grit Sequence for Floor Sanding

• 60 grit: Heavy removal of old finish and deep scratches.
• 100 grit: Intermediate smoothing after coarse sanding.
• 150 grit: Refining and leveling for a clean, even look.
• 220 grit: Final pass before stain or polyurethane.

Step-by-Step: Sanding Wooden Floors

1. Start coarse. Load a drum sander with 60 grit (25-pack) to strip old finish and tackle scratches.
2. Smooth with 100 grit. Use 100 grit (25-pack) to remove coarse marks and prepare for finer sanding.
3. Refine with 150 grit. Switch to 150 grit (50-pack) to blend the floor and smooth transitions.
4. Finish with 220 grit. Sand using 220 grit (100-pack) for a silky surface ready for finishing coats.
5. Edge sanding. Repeat the same grit sequence on edges and corners with an edger sander.
6. Clean thoroughly. Vacuum and wipe with a tack cloth to remove dust before staining or sealing.

Special Cases

Old floors with heavy damage may need two passes with 60 grit. For engineered wood floors, avoid sanding too aggressively as veneer thickness is limited.

Pro Tips

• Always sand in the direction of the wood grain.
• Overlap sanding passes by one-third for even coverage.
• Replace sandpaper frequently—dull sheets burnish wood instead of cutting.

Aftercare

• Apply stain or polyurethane within 24 hours for best adhesion.
• Use floor protectors on furniture legs to prevent scratches.
• Keep sandpaper stored flat and dry for future projects.

FAQs

• Can I skip directly from 60 to 150 grit? No—each step removes scratches left by the previous grit.
• Do I need to sand between polyurethane coats? A light pass with 320 grit between coats ensures a flawless finish.

Watch & Learn

Sanding properly is the foundation of a professional hardwood floor refinish. Explore our floor sanding collection to get the right grits for your project.