How to Sand Hardwood Floor

Why Sanding Matters

Sanding removes the old finish, levels surface imperfections, and opens the wood grain to accept new stain and sealer. Done correctly, it's the step that determines whether your refinished floor looks professional or patchy. Done incorrectly, it creates swirl marks, uneven surfaces, and finish adhesion problems.

Drum Sander vs. Orbital Sander: Which Do You Need?

• Drum sander — rented from hardware stores, aggressive material removal, best for full-room refinishing. Requires experience — stopping in one place for even a second can gouge the floor.
• Orbital sander (DEWALT 20V) — slower material removal, much more forgiving, ideal for spot repairs, edges, and smaller areas. Also good for final smoothing passes on full refinishing jobs.

For a first-time DIYer refinishing a full room, consider renting a drum sander for the main field and using the orbital for edges and corners.

Sandpaper Grit Sequence

Always work through grits progressively — never skip grits. Each grit removes the scratches left by the previous one.

• 36–60 grit — removes old finish, levels high spots, removes deep scratches (drum sander pass)
• 80 grit — removes scratches from 60 grit, begins smoothing the surface
• 100 grit — further smoothing
• 120 grit — final smoothing before stain or sealer

The sandpaper assortment (400–3000 grit) is ideal for final hand-sanding passes and between-coat sanding after applying finish.

Step-by-Step Sanding Process

1. Prepare the room — remove furniture, seal doorways with plastic, open windows
2. Inspect the floor — nail down loose boards, set protruding nails below the surface, fill large gaps
3. First pass (60 grit) — sand in the direction of the grain across the main field. Never stop moving with a drum sander.
4. Edge sand — use the orbital sander along walls and in corners after each drum pass
5. Vacuum and tack cloth — remove all dust before moving to the next grit
6. Second pass (80 grit) — repeat across the field and edges
7. Third pass (100–120 grit) — final smoothing pass
8. Final vacuum and tack cloth — the floor must be completely dust-free before applying any finish

Common Sanding Mistakes to Avoid

• Sanding across the grain — always sand parallel to the wood grain, never perpendicular
• Skipping grits — jumping from 60 to 120 leaves deep scratches that show through the finish
• Stopping the drum sander in one place — creates a visible gouge in seconds
• Not cleaning between grits — coarse grit particles left on the floor scratch the surface during the next pass
• Sanding a cupped floor before it's dry — causes crowning; always confirm moisture levels with a moisture meter first

After Sanding: Next Steps

Once sanding is complete, the floor is ready for staining and sealing. See our guides on how to stain hardwood floors and how to apply polyurethane for the complete finishing process.

Products Used in This Guide

• DEWALT 20V Orbital Sander DCW210B — edges, corners, spot repairs, and final smoothing
• Sandpaper Assortment 400–3000 Grit — between-coat sanding and final hand passes
• General Tools MMD4E Digital Moisture Meter — confirm floor is dry before sanding cupped or water-damaged boards